Commit Graph

4284 Commits

Author SHA1 Message Date
Tejun Heo
54baa7ac0c Revert "sched_ext: Use shorter slice while bypassing"
This reverts commit 6f34d8d382.

Slice length is ignored while bypassing and tasks are switched on every tick
and thus the patch does not make any difference. The perceived difference
was from test noise.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-10-10 11:41:44 -10:00
Honglei Wang
c425180d88 sched_ext: use correct function name in pick_task_scx() warning message
pick_next_task_scx() was turned into pick_task_scx() since
commit 753e2836d1 ("sched_ext: Unify regular and core-sched pick
task paths"). Update the outdated message.

Signed-off-by: Honglei Wang <jameshongleiwang@126.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-10-10 06:35:28 -10:00
Tejun Heo
9b671793c7 sched_ext, scx_qmap: Add and use SCX_ENQ_CPU_SELECTED
scx_qmap and other schedulers in the SCX repo are using SCX_ENQ_WAKEUP to
tell whether ops.select_cpu() was called. This is incorrect as
ops.select_cpu() can be skipped in the wakeup path and leads to e.g.
incorrectly skipping direct dispatch for tasks that are bound to a single
CPU.

sched core has been updated to specify ENQUEUE_RQ_SELECTED if
->select_task_rq() was called. Map it to SCX_ENQ_CPU_SELECTED and update
scx_qmap to test it instead of SCX_ENQ_WAKEUP.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Cc: Daniel Hodges <hodges.daniel.scott@gmail.com>
Cc: Changwoo Min <multics69@gmail.com>
Cc: Andrea Righi <andrea.righi@linux.dev>
Cc: Dan Schatzberg <schatzberg.dan@gmail.com>
2024-10-07 10:16:18 -10:00
Tejun Heo
f207dc2dcd sched/core: Add ENQUEUE_RQ_SELECTED to indicate whether ->select_task_rq() was called
During ttwu, ->select_task_rq() can be skipped if only one CPU is allowed or
migration is disabled. sched_ext schedulers may perform operations such as
direct dispatch from ->select_task_rq() path and it is useful for them to
know whether ->select_task_rq() was skipped in the ->enqueue_task() path.

Currently, sched_ext schedulers are using ENQUEUE_WAKEUP for this purpose
and end up assuming incorrectly that ->select_task_rq() was called for tasks
that are bound to a single CPU or migration disabled.

Make select_task_rq() indicate whether ->select_task_rq() was called by
setting WF_RQ_SELECTED in *wake_flags and make ttwu_do_activate() map that
to ENQUEUE_RQ_SELECTED for ->enqueue_task().

This will be used by sched_ext to fix ->select_task_rq() skip detection.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-10-07 10:16:18 -10:00
Tejun Heo
b62933eee4 sched/core: Make select_task_rq() take the pointer to wake_flags instead of value
This will be used to allow select_task_rq() to indicate whether
->select_task_rq() was called by modifying *wake_flags.

This makes try_to_wake_up() call all functions that take wake_flags with
WF_TTWU set. Previously, only select_task_rq() was. Using the same flags is
more consistent, and, as the flag is only tested by ->select_task_rq()
implementations, it doesn't cause any behavior differences.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-10-07 10:16:18 -10:00
Tejun Heo
ec010333ce sched_ext: scx_cgroup_exit() may be called without successful scx_cgroup_init()
568894edbe ("sched_ext: Add scx_cgroup_enabled to gate cgroup operations
and fix scx_tg_online()") assumed that scx_cgroup_exit() is only called
after scx_cgroup_init() finished successfully. This isn't true.
scx_cgroup_exit() can be called without scx_cgroup_init() being called at
all or after scx_cgroup_init() failed in the middle.

As init state is tracked per cgroup, scx_cgroup_exit() can be used safely to
clean up in all cases. Remove the incorrect WARN_ON_ONCE().

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 568894edbe ("sched_ext: Add scx_cgroup_enabled to gate cgroup operations and fix scx_tg_online()")
2024-10-04 10:12:11 -10:00
Tejun Heo
cc9877fb76 sched_ext: Improve error reporting during loading
When the BPF scheduler fails, ops.exit() allows rich error reporting through
scx_exit_info. Use scx.exit() path consistently for all failures which can
be caused by the BPF scheduler:

- scx_ops_error() is called after ops.init() and ops.cgroup_init() failure
  to record error information.

- ops.init_task() failure now uses scx_ops_error() instead of pr_err().

- The err_disable path updated to automatically trigger scx_ops_error() to
  cover cases that the error message hasn't already been generated and
  always return 0 indicating init success so that the error is reported
  through ops.exit().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Vernet <void@manifault.com>
Cc: Daniel Hodges <hodges.daniel.scott@gmail.com>
Cc: Changwoo Min <multics69@gmail.com>
Cc: Andrea Righi <andrea.righi@linux.dev>
Cc: Dan Schatzberg <schatzberg.dan@gmail.com>
2024-10-04 10:11:43 -10:00
Zhang Qiao
95b873693a sched_ext: Remove redundant p->nr_cpus_allowed checker
select_rq_task() already checked that 'p->nr_cpus_allowed > 1',
'p->nr_cpus_allowed == 1' checker in scx_select_cpu_dfl() is redundant.

Signed-off-by: Zhang Qiao <zhangqiao22@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-27 10:23:45 -10:00
Tejun Heo
efe231d9de sched_ext: Decouple locks in scx_ops_enable()
The enable path uses three big locks - scx_fork_rwsem, scx_cgroup_rwsem and
cpus_read_lock. Currently, the locks are grabbed together which is prone to
locking order problems.

For example, currently, there is a possible deadlock involving
scx_fork_rwsem and cpus_read_lock. cpus_read_lock has to nest inside
scx_fork_rwsem due to locking order existing in other subsystems. However,
there exists a dependency in the other direction during hotplug if hotplug
needs to fork a new task, which happens in some cases. This leads to the
following deadlock:

       scx_ops_enable()                               hotplug

                                          percpu_down_write(&cpu_hotplug_lock)
   percpu_down_write(&scx_fork_rwsem)
   block on cpu_hotplug_lock
                                          kthread_create() waits for kthreadd
					  kthreadd blocks on scx_fork_rwsem

Note that this doesn't trigger lockdep because the hotplug side dependency
bounces through kthreadd.

With the preceding scx_cgroup_enabled change, this can be solved by
decoupling cpus_read_lock, which is needed for static_key manipulations,
from the other two locks.

- Move the first block of static_key manipulations outside of scx_fork_rwsem
  and scx_cgroup_rwsem. This is now safe with the preceding
  scx_cgroup_enabled change.

- Drop scx_cgroup_rwsem and scx_fork_rwsem between the two task iteration
  blocks so that __scx_ops_enabled static_key enabling is outside the two
  rwsems.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Aboorva Devarajan <aboorvad@linux.ibm.com>
Link: http://lkml.kernel.org/r/8cd0ec0c4c7c1bc0119e61fbef0bee9d5e24022d.camel@linux.ibm.com
2024-09-27 10:02:40 -10:00
Tejun Heo
160216568c sched_ext: Decouple locks in scx_ops_disable_workfn()
The disable path uses three big locks - scx_fork_rwsem, scx_cgroup_rwsem and
cpus_read_lock. Currently, the locks are grabbed together which is prone to
locking order problems. With the preceding scx_cgroup_enabled change, we can
decouple them:

- As cgroup disabling no longer requires modifying a static_key which
  requires cpus_read_lock(), no need to grab cpus_read_lock() before
  grabbing scx_cgroup_rwsem.

- cgroup can now be independently disabled before tasks are moved back to
  the fair class.

Relocate scx_cgroup_exit() invocation before scx_fork_rwsem is grabbed, drop
now unnecessary cpus_read_lock() and move static_key operations out of
scx_fork_rwsem. This decouples all three locks in the disable path.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Aboorva Devarajan <aboorvad@linux.ibm.com>
Link: http://lkml.kernel.org/r/8cd0ec0c4c7c1bc0119e61fbef0bee9d5e24022d.camel@linux.ibm.com
2024-09-27 10:02:40 -10:00
Tejun Heo
568894edbe sched_ext: Add scx_cgroup_enabled to gate cgroup operations and fix scx_tg_online()
If the BPF scheduler does not implement ops.cgroup_init(), scx_tg_online()
didn't set SCX_TG_INITED which meant that ops.cgroup_exit(), even if
implemented, won't be called from scx_tg_offline(). This is because
SCX_HAS_OP(cgroupt_init) is used to test both whether SCX cgroup operations
are enabled and ops.cgroup_init() exists.

Fix it by introducing a separate bool scx_cgroup_enabled to gate cgroup
operations and use SCX_HAS_OP(cgroup_init) only to test whether
ops.cgroup_init() exists. Make all cgroup operations consistently use
scx_cgroup_enabled to test whether cgroup operations are enabled.
scx_cgroup_enabled is added instead of using scx_enabled() to ease planned
locking updates.

Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-27 10:02:40 -10:00
Tejun Heo
4269c603cc sched_ext: Enable scx_ops_init_task() separately
scx_ops_init_task() and the follow-up scx_ops_enable_task() in the fork path
were gated by scx_enabled() test and thus __scx_ops_enabled had to be turned
on before the first scx_ops_init_task() loop in scx_ops_enable(). However,
if an external entity causes sched_class switch before the loop is complete,
tasks which are not initialized could be switched to SCX.

The following can be reproduced by running a program which keeps toggling a
process between SCHED_OTHER and SCHED_EXT using sched_setscheduler(2).

  sched_ext: Invalid task state transition 0 -> 3 for fish[1623]
  WARNING: CPU: 1 PID: 1650 at kernel/sched/ext.c:3392 scx_ops_enable_task+0x1a1/0x200
  ...
  Sched_ext: simple (enabling)
  RIP: 0010:scx_ops_enable_task+0x1a1/0x200
  ...
   switching_to_scx+0x13/0xa0
   __sched_setscheduler+0x850/0xa50
   do_sched_setscheduler+0x104/0x1c0
   __x64_sys_sched_setscheduler+0x18/0x30
   do_syscall_64+0x7b/0x140
   entry_SYSCALL_64_after_hwframe+0x76/0x7e

Fix it by gating scx_ops_init_task() separately using
scx_ops_init_task_enabled. __scx_ops_enabled is now set after all tasks are
finished with scx_ops_init_task().

Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-27 10:02:40 -10:00
Tejun Heo
9753358a6a sched_ext: Fix SCX_TASK_INIT -> SCX_TASK_READY transitions in scx_ops_enable()
scx_ops_enable() has two task iteration loops. The first one calls
scx_ops_init_task() on every task and the latter switches the eligible ones
into SCX. The first loop left the tasks in SCX_TASK_INIT state and then the
second loop switched it into READY before switching the task into SCX.

The distinction between INIT and READY is only meaningful in the fork path
where it's used to tell whether the task finished forking so that we can
tell ops.exit_task() accordingly. Leaving task in INIT state between the two
loops is incosistent with the fork path and incorrect. The following can be
triggered by running a program which keeps toggling a task between
SCHED_OTHER and SCHED_SCX while enabling a task:

  sched_ext: Invalid task state transition 1 -> 3 for fish[1526]
  WARNING: CPU: 2 PID: 1615 at kernel/sched/ext.c:3393 scx_ops_enable_task+0x1a1/0x200
  ...
  Sched_ext: qmap (enabling+all)
  RIP: 0010:scx_ops_enable_task+0x1a1/0x200
  ...
   switching_to_scx+0x13/0xa0
   __sched_setscheduler+0x850/0xa50
   do_sched_setscheduler+0x104/0x1c0
   __x64_sys_sched_setscheduler+0x18/0x30
   do_syscall_64+0x7b/0x140
   entry_SYSCALL_64_after_hwframe+0x76/0x7e

Fix it by transitioning to READY in the first loop right after
scx_ops_init_task() succeeds.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Vernet <void@manifault.com>
2024-09-27 10:02:40 -10:00
Tejun Heo
8c2090c504 sched_ext: Initialize in bypass mode
scx_ops_enable() used preempt_disable() around the task iteration loop to
switch tasks into SCX to guarantee forward progress of the task which is
running scx_ops_enable(). However, in the gap between setting
__scx_ops_enabled and preeempt_disable(), an external entity can put tasks
including the enabling one into SCX prematurely, which can lead to
malfunctions including stalls.

The bypass mode can wrap the entire enabling operation and guarantee forward
progress no matter what the BPF scheduler does. Use the bypass mode instead
to guarantee forward progress while enabling.

While at it, release and regrab scx_tasks_lock between the two task
iteration locks in scx_ops_enable() for clarity as there is no reason to
keep holding the lock between them.

Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-27 10:02:40 -10:00
Tejun Heo
fc1fcebead sched_ext: Remove SCX_OPS_PREPPING
The distinction between SCX_OPS_PREPPING and SCX_OPS_ENABLING is not used
anywhere and only adds confusion. Drop SCX_OPS_PREPPING.

Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-27 10:02:39 -10:00
Tejun Heo
1bbcfe620e sched_ext: Relocate check_hotplug_seq() call in scx_ops_enable()
check_hotplug_seq() is used to detect CPU hotplug event which occurred while
the BPF scheduler is being loaded so that initialization can be retried if
CPU hotplug events take place before the CPU hotplug callbacks are online.

As such, the best place to call it is in the same cpu_read_lock() section
that enables the CPU hotplug ops. Currently, it is called in the next
cpus_read_lock() block in scx_ops_enable(). The side effect of this
placement is a small window in which hotplug sequence detection can trigger
unnecessarily, which isn't critical.

Move check_hotplug_seq() invocation to the same cpus_read_lock() block as
the hotplug operation enablement to close the window and get the invocation
out of the way for planned locking updates.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Vernet <void@manifault.com>
2024-09-27 10:02:39 -10:00
Tejun Heo
6f34d8d382 sched_ext: Use shorter slice while bypassing
While bypassing, tasks are scheduled in FIFO order which favors tasks that
hog CPUs. This can slow down e.g. unloading of the BPF scheduler. While
bypassing, guaranteeing timely forward progress is the main goal. There's no
point in giving long slices. Shorten the time slice used while bypassing
from 20ms to 5ms.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-09-26 12:56:46 -10:00
Tejun Heo
b7b3b2dbae sched_ext: Split the global DSQ per NUMA node
In the bypass mode, the global DSQ is used to schedule all tasks in simple
FIFO order. All tasks are queued into the global DSQ and all CPUs try to
execute tasks from it. This creates a lot of cross-node cacheline accesses
and scheduling across the node boundaries, and can lead to live-lock
conditions where the system takes tens of minutes to disable the BPF
scheduler while executing in the bypass mode.

Split the global DSQ per NUMA node. Each node has its own global DSQ. When a
task is dispatched to SCX_DSQ_GLOBAL, it's put into the global DSQ local to
the task's CPU and all CPUs in a node only consume its node-local global
DSQ.

This resolves a livelock condition which could be reliably triggered on an
2x EPYC 7642 system by running `stress-ng --race-sched 1024` together with
`stress-ng --workload 80 --workload-threads 10` while repeatedly enabling
and disabling a SCX scheduler.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-09-26 12:56:46 -10:00
Tejun Heo
bba26bf356 sched_ext: Relocate find_user_dsq()
To prepare for the addition of find_global_dsq(). No functional changes.

Signed-off-by: tejun heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-09-26 12:56:46 -10:00
Tejun Heo
63fb3ec805 sched_ext: Allow only user DSQs for scx_bpf_consume(), scx_bpf_dsq_nr_queued() and bpf_iter_scx_dsq_new()
SCX_DSQ_GLOBAL is special in that it can't be used as a priority queue and
is consumed implicitly, but all BPF DSQ related kfuncs could be used on it.
SCX_DSQ_GLOBAL will be split per-node for scalability and those operations
won't make sense anymore. Disallow SCX_DSQ_GLOBAL on scx_bpf_consume(),
scx_bpf_dsq_nr_queued() and bpf_iter_scx_dsq_new(). This means that
SCX_DSQ_GLOBAL can only be used as a dispatch target from BPF schedulers.

With scx_flatcg, which was using SCX_DSQ_GLOBAL as the fallback DSQ,
updated, this shouldn't affect any schedulers.

This leaves find_dsq_for_dispatch() the only user of find_non_local_dsq().
Open code and remove find_non_local_dsq().

Signed-off-by: tejun heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-09-26 12:56:46 -10:00
Tejun Heo
42268ad0eb sched_ext: Build fix for !CONFIG_SMP
move_remote_task_to_local_dsq() is only defined on SMP configs but
scx_disaptch_from_dsq() was calling move_remote_task_to_local_dsq() on UP
configs too causing build failures. Add a dummy
move_remote_task_to_local_dsq() which triggers a warning.

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 4c30f5ce4f ("sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq()")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409241108.jaocHiDJ-lkp@intel.com/
2024-09-24 11:10:07 -10:00
Andrea Righi
431844b65f sched_ext: Provide a sysfs enable_seq counter
As discussed during the distro-centric session within the sched_ext
Microconference at LPC 2024, introduce a sequence counter that is
incremented every time a BPF scheduler is loaded.

This feature can help distributions in diagnosing potential performance
regressions by identifying systems where users are running (or have ran)
custom BPF schedulers.

Example:

 arighi@virtme-ng~> cat /sys/kernel/sched_ext/enable_seq
 0
 arighi@virtme-ng~> sudo scx_simple
 local=1 global=0
 ^CEXIT: unregistered from user space
 arighi@virtme-ng~> cat /sys/kernel/sched_ext/enable_seq
 1

In this way user-space tools (such as Ubuntu's apport and similar) are
able to gather and include this information in bug reports.

Cc: Giovanni Gherdovich <giovanni.gherdovich@suse.com>
Cc: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Cc: Marcelo Henrique Cerri <marcelo.cerri@canonical.com>
Cc: Phil Auld <pauld@redhat.com>
Signed-off-by: Andrea Righi <andrea.righi@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-23 06:53:02 -10:00
Tejun Heo
62d3726d4c sched_ext: Fix build when !CONFIG_STACKTRACE
a2f4b16e73 ("sched_ext: Build fix on !CONFIG_STACKTRACE[_SUPPORT]") tried
fixing build when !CONFIG_STACKTRACE but didn't so fully. Also put
stack_trace_print() and stack_trace_save() inside CONFIG_STACKTRACE to fix
build when !CONFIG_STACKTRACE.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409220642.fDW2OmWc-lkp@intel.com/
2024-09-23 06:45:22 -10:00
Pat Somaru
edf1c586e9 sched, sched_ext: Disable SM_IDLE/rq empty path when scx_enabled()
Disable the rq empty path when scx is enabled. SCX must consult the BPF
scheduler (via the dispatch path in balance) to determine if rq is empty.

This fixes stalls when scx is enabled.

Signed-off-by: Pat Somaru <patso@likewhatevs.io>
Fixes: 3dcac251b0 ("sched/core: Introduce SM_IDLE and an idle re-entry fast-path in __schedule()")
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-23 05:40:53 -10:00
Yu Liao
7ebd84d627 sched: Put task_group::idle under CONFIG_GROUP_SCHED_WEIGHT
When build with CONFIG_GROUP_SCHED_WEIGHT && !CONFIG_FAIR_GROUP_SCHED,
the idle member is not defined:

kernel/sched/ext.c:3701:16: error: 'struct task_group' has no member named 'idle'
  3701 |         if (!tg->idle)
       |                ^~

Fix this by putting 'idle' under new CONFIG_GROUP_SCHED_WEIGHT.

tj: Move idle field upward to avoid breaking up CONFIG_FAIR_GROUP_SCHED block.

Fixes: e179e80c5d ("sched: Introduce CONFIG_GROUP_SCHED_WEIGHT")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409220859.UiCAoFOW-lkp@intel.com/
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-23 05:24:12 -10:00
Yu Liao
bdeb868c0d sched: Add dummy version of sched_group_set_idle()
Fix the following error when build with CONFIG_GROUP_SCHED_WEIGHT &&
!CONFIG_FAIR_GROUP_SCHED:

kernel/sched/core.c:9634:15: error: implicit declaration of function
'sched_group_set_idle'; did you mean 'scx_group_set_idle'? [-Wimplicit-function-declaration]
  9634 |         ret = sched_group_set_idle(css_tg(css), idle);
       |               ^~~~~~~~~~~~~~~~~~~~
       |               scx_group_set_idle

Fixes: e179e80c5d ("sched: Introduce CONFIG_GROUP_SCHED_WEIGHT")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409220859.UiCAoFOW-lkp@intel.com/
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-23 05:18:03 -10:00
Linus Torvalds
88264981f2 sched_ext: Initial pull request for v6.12
This is the initial pull request of sched_ext. The v7 patchset
 (https://lkml.kernel.org/r/20240618212056.2833381-1-tj@kernel.org) is
 applied on top of tip/sched/core + bpf/master as of Jun 18th.
 
   tip/sched/core 793a62823d1c ("sched/core: Drop spinlocks on contention iff kernel is preempti
 ble")
   bpf/master f6afdaf72a ("Merge branch 'bpf-support-resilient-split-btf'")
 
 Since then, the following pulls were made:
 
 - v6.11-rc1 is pulled to keep up with the mainline.
 
 - tip/sched/core was pulled several times:
 
   - 7b9f6c864a, 0df340ceae, 5ac998574f, 0b1777f0fa: To resolve
     conflicts. See each commit for details on conflicts and their
     resolutions.
 
   - d7b01aef9d: To receive fd03c5b858 ("sched: Rework pick_next_task()")
     and related commits. @prev in added to sched_class->put_prev_task() and
     put_prev_task() is reordered after ->pick_task(), which makes
     sched_class->switch_class() unnecessary. The follow-up commits update
     sched_ext accordingly and drop sched_class->switch_class().
 
 - bpf/master was pulled to receive baebe9aaba ("bpf: allow passing struct
   bpf_iter_<type> as kfunc arguments") and related changes in preparation
   for the DSQ iterator patchset
 
 To obtain the net sched_ext changes, diff against:
 
   git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext.git for-6.12-base
 
 which is the merge of:
 
   tip/sched/core bc9057da1a ("sched/cpufreq: Use NSEC_PER_MSEC for deadline task")
   bpf/master 2ad6d23f46 ("selftests/bpf: Do not update vmlinux.h unnecessarily")
 
 Since the v7 patchset, the following changes were made:
 
 - cpuperf support which was a part of the v6 patchset was posted separately
   and then applied after reviews.
 
 - cgroup support which was a part of the v6 patchset was posted seprately,
   iterated and then applied.
 
 - Improve integration with sched core.
 
 - Double locking usage in migration paths dropped. Depend on
   TASK_ON_RQ_MIGRATING synchronization instead.
 
 - The BPF scheduler couldn't directly dispatch to the local DSQ of another
   CPU using a SCX_DSQ_LOCAL_ON verdict. This caused difficulties around
   handling non-wakeup enqueues. Updated so that SCX_DSQ_LOCAL_ON can be used
   in the enqueue path too.
 
 - DSQ iterator which was a part of the v6 patchset was posted separately.
   The iterator itself was applied after a couple revisions. The associated
   selective consumption kfunc can use further improvements and is still
   being worked on.
 
 - scx_bpf_dispatch[_vtime]_from_dsq() added to increase flexibility. A task
   can now be transferred between two DSQs from almost any context. This
   involved significant refactoring of migration code.
 
 - Various fixes and improvements.
 
 As the branch is based on top of tip/sched/core + bpf/master, please merge
 after both are applied.
 -----BEGIN PGP SIGNATURE-----
 
 iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCZuOSuA4cdGpAa2VybmVs
 Lm9yZwAKCRCxYfJx3gVYGVZyAQDBU3WPkYKB8gl6a6YQ+/PzBXorOK7mioS9A2iJ
 vBR3FgEAg1vtcss1S+2juWmVq7ItiFNWCqtXzUr/bVmL9CqqDwA=
 =bOOC
 -----END PGP SIGNATURE-----

Merge tag 'sched_ext-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

Pull sched_ext support from Tejun Heo:
 "This implements a new scheduler class called ‘ext_sched_class’, or
  sched_ext, which allows scheduling policies to be implemented as BPF
  programs.

  The goals of this are:

   - Ease of experimentation and exploration: Enabling rapid iteration
     of new scheduling policies.

   - Customization: Building application-specific schedulers which
     implement policies that are not applicable to general-purpose
     schedulers.

   - Rapid scheduler deployments: Non-disruptive swap outs of scheduling
     policies in production environments"

See individual commits for more documentation, but also the cover letter
for the latest series:

Link: https://lore.kernel.org/all/20240618212056.2833381-1-tj@kernel.org/

* tag 'sched_ext-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (110 commits)
  sched: Move update_other_load_avgs() to kernel/sched/pelt.c
  sched_ext: Don't trigger ops.quiescent/runnable() on migrations
  sched_ext: Synchronize bypass state changes with rq lock
  scx_qmap: Implement highpri boosting
  sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq()
  sched_ext: Compact struct bpf_iter_scx_dsq_kern
  sched_ext: Replace consume_local_task() with move_local_task_to_local_dsq()
  sched_ext: Move consume_local_task() upward
  sched_ext: Move sanity check and dsq_mod_nr() into task_unlink_from_dsq()
  sched_ext: Reorder args for consume_local/remote_task()
  sched_ext: Restructure dispatch_to_local_dsq()
  sched_ext: Fix processs_ddsp_deferred_locals() by unifying DTL_INVALID handling
  sched_ext: Make find_dsq_for_dispatch() handle SCX_DSQ_LOCAL_ON
  sched_ext: Refactor consume_remote_task()
  sched_ext: Rename scx_kfunc_set_sleepable to unlocked and relocate
  sched_ext: Add missing static to scx_dump_data
  sched_ext: Add missing static to scx_has_op[]
  sched_ext: Temporarily work around pick_task_scx() being called without balance_scx()
  sched_ext: Add a cgroup scheduler which uses flattened hierarchy
  sched_ext: Add cgroup support
  ...
2024-09-21 09:44:57 -07:00
Linus Torvalds
617a814f14 ALong with the usual shower of singleton patches, notable patch series in
this pull request are:
 
 "Align kvrealloc() with krealloc()" from Danilo Krummrich.  Adds
 consistency to the APIs and behaviour of these two core allocation
 functions.  This also simplifies/enables Rustification.
 
 "Some cleanups for shmem" from Baolin Wang.  No functional changes - mode
 code reuse, better function naming, logic simplifications.
 
 "mm: some small page fault cleanups" from Josef Bacik.  No functional
 changes - code cleanups only.
 
 "Various memory tiering fixes" from Zi Yan.  A small fix and a little
 cleanup.
 
 "mm/swap: remove boilerplate" from Yu Zhao.  Code cleanups and
 simplifications and .text shrinkage.
 
 "Kernel stack usage histogram" from Pasha Tatashin and Shakeel Butt.  This
 is a feature, it adds new feilds to /proc/vmstat such as
 
     $ grep kstack /proc/vmstat
     kstack_1k 3
     kstack_2k 188
     kstack_4k 11391
     kstack_8k 243
     kstack_16k 0
 
 which tells us that 11391 processes used 4k of stack while none at all
 used 16k.  Useful for some system tuning things, but partivularly useful
 for "the dynamic kernel stack project".
 
 "kmemleak: support for percpu memory leak detect" from Pavel Tikhomirov.
 Teaches kmemleak to detect leaksage of percpu memory.
 
 "mm: memcg: page counters optimizations" from Roman Gushchin.  "3
 independent small optimizations of page counters".
 
 "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from David
 Hildenbrand.  Improves PTE/PMD splitlock detection, makes powerpc/8xx work
 correctly by design rather than by accident.
 
 "mm: remove arch_make_page_accessible()" from David Hildenbrand.  Some
 folio conversions which make arch_make_page_accessible() unneeded.
 
 "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David Finkel.
 Cleans up and fixes our handling of the resetting of the cgroup/process
 peak-memory-use detector.
 
 "Make core VMA operations internal and testable" from Lorenzo Stoakes.
 Rationalizaion and encapsulation of the VMA manipulation APIs.  With a
 view to better enable testing of the VMA functions, even from a
 userspace-only harness.
 
 "mm: zswap: fixes for global shrinker" from Takero Funaki.  Fix issues in
 the zswap global shrinker, resulting in improved performance.
 
 "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao.  Fill in
 some missing info in /proc/zoneinfo.
 
 "mm: replace follow_page() by folio_walk" from David Hildenbrand.  Code
 cleanups and rationalizations (conversion to folio_walk()) resulting in
 the removal of follow_page().
 
 "improving dynamic zswap shrinker protection scheme" from Nhat Pham.  Some
 tuning to improve zswap's dynamic shrinker.  Significant reductions in
 swapin and improvements in performance are shown.
 
 "mm: Fix several issues with unaccepted memory" from Kirill Shutemov.
 Improvements to the new unaccepted memory feature,
 
 "mm/mprotect: Fix dax puds" from Peter Xu.  Implements mprotect on DAX
 PUDs.  This was missing, although nobody seems to have notied yet.
 
 "Introduce a store type enum for the Maple tree" from Sidhartha Kumar.
 Cleanups and modest performance improvements for the maple tree library
 code.
 
 "memcg: further decouple v1 code from v2" from Shakeel Butt.  Move more
 cgroup v1 remnants away from the v2 memcg code.
 
 "memcg: initiate deprecation of v1 features" from Shakeel Butt.  Adds
 various warnings telling users that memcg v1 features are deprecated.
 
 "mm: swap: mTHP swap allocator base on swap cluster order" from Chris Li.
 Greatly improves the success rate of the mTHP swap allocation.
 
 "mm: introduce numa_memblks" from Mike Rapoport.  Moves various disparate
 per-arch implementations of numa_memblk code into generic code.
 
 "mm: batch free swaps for zap_pte_range()" from Barry Song.  Greatly
 improves the performance of munmap() of swap-filled ptes.
 
 "support large folio swap-out and swap-in for shmem" from Baolin Wang.
 With this series we no longer split shmem large folios into simgle-page
 folios when swapping out shmem.
 
 "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao.  Nice performance
 improvements and code reductions for gigantic folios.
 
 "support shmem mTHP collapse" from Baolin Wang.  Adds support for
 khugepaged's collapsing of shmem mTHP folios.
 
 "mm: Optimize mseal checks" from Pedro Falcato.  Fixes an mprotect()
 performance regression due to the addition of mseal().
 
 "Increase the number of bits available in page_type" from Matthew Wilcox.
 Increases the number of bits available in page_type!
 
 "Simplify the page flags a little" from Matthew Wilcox.  Many legacy page
 flags are now folio flags, so the page-based flags and their
 accessors/mutators can be removed.
 
 "mm: store zero pages to be swapped out in a bitmap" from Usama Arif.  An
 optimization which permits us to avoid writing/reading zero-filled zswap
 pages to backing store.
 
 "Avoid MAP_FIXED gap exposure" from Liam Howlett.  Fixes a race window
 which occurs when a MAP_FIXED operqtion is occurring during an unrelated
 vma tree walk.
 
 "mm: remove vma_merge()" from Lorenzo Stoakes.  Major rotorooting of the
 vma_merge() functionality, making ot cleaner, more testable and better
 tested.
 
 "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.  Minor
 fixups of DAMON selftests and kunit tests.
 
 "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.  Code
 cleanups and folio conversions.
 
 "Shmem mTHP controls and stats improvements" from Ryan Roberts.  Cleanups
 for shmem controls and stats.
 
 "mm: count the number of anonymous THPs per size" from Barry Song.  Expose
 additional anon THP stats to userspace for improved tuning.
 
 "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more folio
 conversions and removal of now-unused page-based APIs.
 
 "replace per-quota region priorities histogram buffer with per-context
 one" from SeongJae Park.  DAMON histogram rationalization.
 
 "Docs/damon: update GitHub repo URLs and maintainer-profile" from SeongJae
 Park.  DAMON documentation updates.
 
 "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and improve
 related doc and warn" from Jason Wang: fixes usage of page allocator
 __GFP_NOFAIL and GFP_ATOMIC flags.
 
 "mm: split underused THPs" from Yu Zhao.  Improve THP=always policy - this
 was overprovisioning THPs in sparsely accessed memory areas.
 
 "zram: introduce custom comp backends API" frm Sergey Senozhatsky.  Add
 support for zram run-time compression algorithm tuning.
 
 "mm: Care about shadow stack guard gap when getting an unmapped area" from
 Mark Brown.  Fix up the various arch_get_unmapped_area() implementations
 to better respect guard areas.
 
 "Improve mem_cgroup_iter()" from Kinsey Ho.  Improve the reliability of
 mem_cgroup_iter() and various code cleanups.
 
 "mm: Support huge pfnmaps" from Peter Xu.  Extends the usage of huge
 pfnmap support.
 
 "resource: Fix region_intersects() vs add_memory_driver_managed()" from
 Huang Ying.  Fix a bug in region_intersects() for systems with CXL memory.
 
 "mm: hwpoison: two more poison recovery" from Kefeng Wang.  Teaches a
 couple more code paths to correctly recover from the encountering of
 poisoned memry.
 
 "mm: enable large folios swap-in support" from Barry Song.  Support the
 swapin of mTHP memory into appropriately-sized folios, rather than into
 single-page folios.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZu1BBwAKCRDdBJ7gKXxA
 jlWNAQDYlqQLun7bgsAN4sSvi27VUuWv1q70jlMXTfmjJAvQqwD/fBFVR6IOOiw7
 AkDbKWP2k0hWPiNJBGwoqxdHHx09Xgo=
 =s0T+
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Along with the usual shower of singleton patches, notable patch series
  in this pull request are:

   - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
     consistency to the APIs and behaviour of these two core allocation
     functions. This also simplifies/enables Rustification.

   - "Some cleanups for shmem" from Baolin Wang. No functional changes -
     mode code reuse, better function naming, logic simplifications.

   - "mm: some small page fault cleanups" from Josef Bacik. No
     functional changes - code cleanups only.

   - "Various memory tiering fixes" from Zi Yan. A small fix and a
     little cleanup.

   - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
     simplifications and .text shrinkage.

   - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
     Butt. This is a feature, it adds new feilds to /proc/vmstat such as

       $ grep kstack /proc/vmstat
       kstack_1k 3
       kstack_2k 188
       kstack_4k 11391
       kstack_8k 243
       kstack_16k 0

     which tells us that 11391 processes used 4k of stack while none at
     all used 16k. Useful for some system tuning things, but
     partivularly useful for "the dynamic kernel stack project".

   - "kmemleak: support for percpu memory leak detect" from Pavel
     Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.

   - "mm: memcg: page counters optimizations" from Roman Gushchin. "3
     independent small optimizations of page counters".

   - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
     David Hildenbrand. Improves PTE/PMD splitlock detection, makes
     powerpc/8xx work correctly by design rather than by accident.

   - "mm: remove arch_make_page_accessible()" from David Hildenbrand.
     Some folio conversions which make arch_make_page_accessible()
     unneeded.

   - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
     Finkel. Cleans up and fixes our handling of the resetting of the
     cgroup/process peak-memory-use detector.

   - "Make core VMA operations internal and testable" from Lorenzo
     Stoakes. Rationalizaion and encapsulation of the VMA manipulation
     APIs. With a view to better enable testing of the VMA functions,
     even from a userspace-only harness.

   - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
     issues in the zswap global shrinker, resulting in improved
     performance.

   - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
     in some missing info in /proc/zoneinfo.

   - "mm: replace follow_page() by folio_walk" from David Hildenbrand.
     Code cleanups and rationalizations (conversion to folio_walk())
     resulting in the removal of follow_page().

   - "improving dynamic zswap shrinker protection scheme" from Nhat
     Pham. Some tuning to improve zswap's dynamic shrinker. Significant
     reductions in swapin and improvements in performance are shown.

   - "mm: Fix several issues with unaccepted memory" from Kirill
     Shutemov. Improvements to the new unaccepted memory feature,

   - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
     DAX PUDs. This was missing, although nobody seems to have notied
     yet.

   - "Introduce a store type enum for the Maple tree" from Sidhartha
     Kumar. Cleanups and modest performance improvements for the maple
     tree library code.

   - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
     more cgroup v1 remnants away from the v2 memcg code.

   - "memcg: initiate deprecation of v1 features" from Shakeel Butt.
     Adds various warnings telling users that memcg v1 features are
     deprecated.

   - "mm: swap: mTHP swap allocator base on swap cluster order" from
     Chris Li. Greatly improves the success rate of the mTHP swap
     allocation.

   - "mm: introduce numa_memblks" from Mike Rapoport. Moves various
     disparate per-arch implementations of numa_memblk code into generic
     code.

   - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
     improves the performance of munmap() of swap-filled ptes.

   - "support large folio swap-out and swap-in for shmem" from Baolin
     Wang. With this series we no longer split shmem large folios into
     simgle-page folios when swapping out shmem.

   - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
     performance improvements and code reductions for gigantic folios.

   - "support shmem mTHP collapse" from Baolin Wang. Adds support for
     khugepaged's collapsing of shmem mTHP folios.

   - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
     performance regression due to the addition of mseal().

   - "Increase the number of bits available in page_type" from Matthew
     Wilcox. Increases the number of bits available in page_type!

   - "Simplify the page flags a little" from Matthew Wilcox. Many legacy
     page flags are now folio flags, so the page-based flags and their
     accessors/mutators can be removed.

   - "mm: store zero pages to be swapped out in a bitmap" from Usama
     Arif. An optimization which permits us to avoid writing/reading
     zero-filled zswap pages to backing store.

   - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
     window which occurs when a MAP_FIXED operqtion is occurring during
     an unrelated vma tree walk.

   - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
     the vma_merge() functionality, making ot cleaner, more testable and
     better tested.

   - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
     Minor fixups of DAMON selftests and kunit tests.

   - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
     Code cleanups and folio conversions.

   - "Shmem mTHP controls and stats improvements" from Ryan Roberts.
     Cleanups for shmem controls and stats.

   - "mm: count the number of anonymous THPs per size" from Barry Song.
     Expose additional anon THP stats to userspace for improved tuning.

   - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
     folio conversions and removal of now-unused page-based APIs.

   - "replace per-quota region priorities histogram buffer with
     per-context one" from SeongJae Park. DAMON histogram
     rationalization.

   - "Docs/damon: update GitHub repo URLs and maintainer-profile" from
     SeongJae Park. DAMON documentation updates.

   - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
     improve related doc and warn" from Jason Wang: fixes usage of page
     allocator __GFP_NOFAIL and GFP_ATOMIC flags.

   - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
     This was overprovisioning THPs in sparsely accessed memory areas.

   - "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
     Add support for zram run-time compression algorithm tuning.

   - "mm: Care about shadow stack guard gap when getting an unmapped
     area" from Mark Brown. Fix up the various arch_get_unmapped_area()
     implementations to better respect guard areas.

   - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
     of mem_cgroup_iter() and various code cleanups.

   - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
     pfnmap support.

   - "resource: Fix region_intersects() vs add_memory_driver_managed()"
     from Huang Ying. Fix a bug in region_intersects() for systems with
     CXL memory.

   - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
     a couple more code paths to correctly recover from the encountering
     of poisoned memry.

   - "mm: enable large folios swap-in support" from Barry Song. Support
     the swapin of mTHP memory into appropriately-sized folios, rather
     than into single-page folios"

* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
  zram: free secondary algorithms names
  uprobes: turn xol_area->pages[2] into xol_area->page
  uprobes: introduce the global struct vm_special_mapping xol_mapping
  Revert "uprobes: use vm_special_mapping close() functionality"
  mm: support large folios swap-in for sync io devices
  mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
  mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
  mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
  set_memory: add __must_check to generic stubs
  mm/vma: return the exact errno in vms_gather_munmap_vmas()
  memcg: cleanup with !CONFIG_MEMCG_V1
  mm/show_mem.c: report alloc tags in human readable units
  mm: support poison recovery from copy_present_page()
  mm: support poison recovery from do_cow_fault()
  resource, kunit: add test case for region_intersects()
  resource: make alloc_free_mem_region() works for iomem_resource
  mm: z3fold: deprecate CONFIG_Z3FOLD
  vfio/pci: implement huge_fault support
  mm/arm64: support large pfn mappings
  mm/x86: support large pfn mappings
  ...
2024-09-21 07:29:05 -07:00
Linus Torvalds
2004cef11e In the v6.12 scheduler development cycle we had 63 commits from 18 contributors:
- Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot de Oliveira's
    last major contribution to the kernel:
 
      "SCHED_DEADLINE servers can help fixing starvation issues of low priority
      tasks (e.g., SCHED_OTHER) when higher priority tasks monopolize CPU
      cycles. Today we have RT Throttling; DEADLINE servers should be able to
      replace and improve that."
 
      (Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes,
       Youssef Esmat, Huang Shijie)
 
  - Preparatory changes for sched_ext integration:
 
      - Use set_next_task(.first) where required
      - Fix up set_next_task() implementations
      - Clean up DL server vs. core sched
      - Split up put_prev_task_balance()
      - Rework pick_next_task()
      - Combine the last put_prev_task() and the first set_next_task()
      - Rework dl_server
      - Add put_prev_task(.next)
 
       (Peter Zijlstra, with a fix by Tejun Heo)
 
  - Complete the EEVDF transition and refine EEVDF scheduling:
 
      - Implement delayed dequeue
      - Allow shorter slices to wakeup-preempt
      - Use sched_attr::sched_runtime to set request/slice suggestion
      - Document the new feature flags
      - Remove unused and duplicate-functionality fields
      - Simplify & unify pick_next_task_fair()
      - Misc debuggability enhancements
 
       (Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann,
        Valentin Schneider and Chuyi Zhou)
 
  - Initialize the vruntime of a new task when it is first enqueued,
    resulting in significant decrease in latency of newly woken tasks.
    (Zhang Qiao)
 
  - Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
    (K Prateek Nayak, Peter Zijlstra)
 
  - Clean up and clarify the usage of Clean up usage of rt_task()
    (Qais Yousef)
 
  - Preempt SCHED_IDLE entities in strict cgroup hierarchies
    (Tianchen Ding)
 
  - Clarify the documentation of time units for deadline scheduler
    parameters. (Christian Loehle)
 
  - Remove the HZ_BW chicken-bit feature flag introduced a year ago,
    the original change seems to be working fine.
    (Phil Auld)
 
  - Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie,
    Peilin He, Qais Yousefm and Vincent Guittot)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmbr8qcRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1gdbw/+Mj3zWfYP+dtUkfgrR2FClPAJoo1/9Dz0
 LYD8XgYHu8rEJ0Aq+VbdkgYGUt9utvzUFPIxvWFDcldQl57KwhF4hp9Ir+PqJyYC
 NolQ1q8ddo1hnslxnEg6SgHVzQq/4FqMM0nDNUkQETCx6zTyFFeRf+q7o/2c2m5B
 uI9dSU1Wrx7XrXm2D3kB8+xP+ZRy+qhbFN5Pfuz96mhelfklylgKMfPzgAiCT/7T
 JTbQhQ2HdcCNgiLoSrWsHBDy2UYpouP4zb4jyd+lDQzhSUJrj3u4Xy4vVmuTKq+y
 sTgWlgKB+MTuh9UuJ4UYzSnMqg161UlMvtXeH84ABmAqDNGHRPtOKrrlcLtJ3D4x
 m1SPhNnsvpjOu2pH0XLIS8al3VUesWND5S+rucHRYSq6Nvhivf4MTvRJlicXXurL
 Mt2APnIlhGJuKBNWnmyZovVdtO0ZUUPlaZWfr3rCS4txAVo+HwWhsm3uhtTycQqN
 gazsCiuGh6Jds90ZqA/BvdLWG+DY8J0xLlV3ex4pCXuQ/HFrabVWTyThJsULhrZ2
 5mTdWIsocPctNMO9/RHMy7vJI7G7ljgHEquWVn5kiGGzXhK6VwVwKAMpfgXGw+YA
 yVP6/M7a7g2yEzj69gXkcDa8k/kedMVquJ/G/8YhZM7u7sPqsMjpmaGsqsJRfnpT
 ChngAzap+kA=
 =TEC6
 -----END PGP SIGNATURE-----

Merge tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:

 - Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot
   de Oliveira's last major contribution to the kernel:

     "SCHED_DEADLINE servers can help fixing starvation issues of low
      priority tasks (e.g., SCHED_OTHER) when higher priority tasks
      monopolize CPU cycles. Today we have RT Throttling; DEADLINE
      servers should be able to replace and improve that."

   (Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes, Youssef
   Esmat, Huang Shijie)

 - Preparatory changes for sched_ext integration:
     - Use set_next_task(.first) where required
     - Fix up set_next_task() implementations
     - Clean up DL server vs. core sched
     - Split up put_prev_task_balance()
     - Rework pick_next_task()
     - Combine the last put_prev_task() and the first set_next_task()
     - Rework dl_server
     - Add put_prev_task(.next)

   (Peter Zijlstra, with a fix by Tejun Heo)

 - Complete the EEVDF transition and refine EEVDF scheduling:
     - Implement delayed dequeue
     - Allow shorter slices to wakeup-preempt
     - Use sched_attr::sched_runtime to set request/slice suggestion
     - Document the new feature flags
     - Remove unused and duplicate-functionality fields
     - Simplify & unify pick_next_task_fair()
     - Misc debuggability enhancements

   (Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann, Valentin
   Schneider and Chuyi Zhou)

 - Initialize the vruntime of a new task when it is first enqueued,
   resulting in significant decrease in latency of newly woken tasks
   (Zhang Qiao)

 - Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
   (K Prateek Nayak, Peter Zijlstra)

 - Clean up and clarify the usage of Clean up usage of rt_task()
   (Qais Yousef)

 - Preempt SCHED_IDLE entities in strict cgroup hierarchies
   (Tianchen Ding)

 - Clarify the documentation of time units for deadline scheduler
   parameters (Christian Loehle)

 - Remove the HZ_BW chicken-bit feature flag introduced a year ago,
   the original change seems to be working fine (Phil Auld)

 - Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie,
   Peilin He, Qais Yousefm and Vincent Guittot)

* tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
  sched/cpufreq: Use NSEC_PER_MSEC for deadline task
  cpufreq/cppc: Use NSEC_PER_MSEC for deadline task
  sched/deadline: Clarify nanoseconds in uapi
  sched/deadline: Convert schedtool example to chrt
  sched/debug: Fix the runnable tasks output
  sched: Fix sched_delayed vs sched_core
  kernel/sched: Fix util_est accounting for DELAY_DEQUEUE
  kthread: Fix task state in kthread worker if being frozen
  sched/pelt: Use rq_clock_task() for hw_pressure
  sched/fair: Move effective_cpu_util() and effective_cpu_util() in fair.c
  sched/core: Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
  sched: Add put_prev_task(.next)
  sched: Rework dl_server
  sched: Combine the last put_prev_task() and the first set_next_task()
  sched: Rework pick_next_task()
  sched: Split up put_prev_task_balance()
  sched: Clean up DL server vs core sched
  sched: Fixup set_next_task() implementations
  sched: Use set_next_task(.first) where required
  sched/fair: Properly deactivate sched_delayed task upon class change
  ...
2024-09-19 15:55:58 +02:00
Linus Torvalds
067610ebaa RCU pull request for v6.12
This pull request contains the following branches:
 
 context_tracking.15.08.24a: Rename context tracking state related
         symbols and remove references to "dynticks" in various context
         tracking state variables and related helpers; force
         context_tracking_enabled_this_cpu() to be inlined to avoid
         leaving a noinstr section.
 
 csd.lock.15.08.24a: Enhance CSD-lock diagnostic reports; add an API
         to provide an indication of ongoing CSD-lock stall.
 
 nocb.09.09.24a: Update and simplify RCU nocb code to handle
         (de-)offloading of callbacks only for offline CPUs; fix RT
         throttling hrtimer being armed from offline CPU.
 
 rcutorture.14.08.24a: Remove redundant rcu_torture_ops get_gp_completed
         fields; add SRCU ->same_gp_state and ->get_comp_state
         functions; add generic test for NUM_ACTIVE_*RCU_POLL* for
         testing RCU and SRCU polled grace periods; add CFcommon.arch
         for arch-specific Kconfig options; print number of update types
         in rcu_torture_write_types();
         add rcutree.nohz_full_patience_delay testing to the TREE07
         scenario; add a stall_cpu_repeat module parameter to test
         repeated CPU stalls; add argument to limit number of CPUs a
         guest OS can use in torture.sh;
 
 rcustall.09.09.24a: Abbreviate RCU CPU stall warnings during CSD-lock
         stalls; Allow dump_cpu_task() to be called without disabling
         preemption; defer printing stall-warning backtrace when holding
         rcu_node lock.
 
 srcu.12.08.24a: Make SRCU gp seq wrap-around faster; add KCSAN checks
         for concurrent updates to ->srcu_n_exp_nodelay and
         ->reschedule_count which are used in heuristics governing
         auto-expediting of normal SRCU grace periods and
         grace-period-state-machine delays; mark idle SRCU-barrier
         callbacks to help identify stuck SRCU-barrier callback.
 
 rcu.tasks.14.08.24a: Remove RCU Tasks Rude asynchronous APIs as they
         are no longer used; stop testing RCU Tasks Rude asynchronous
         APIs; fix access to non-existent percpu regions; check
         processor-ID assumptions during chosen CPU calculation for
         callback enqueuing; update description of rtp->tasks_gp_seq
         grace-period sequence number; add rcu_barrier_cb_is_done()
         to identify whether a given rcu_barrier callback is stuck;
         mark idle Tasks-RCU-barrier callbacks; add
         *torture_stats_print() functions to print detailed
         diagnostics for Tasks-RCU variants; capture start time of
         rcu_barrier_tasks*() operation to help distinguish a hung
         barrier operation from a long series of barrier operations.
 
 rcu_scaling_tests.15.08.24a:
         refscale: Add a TINY scenario to support tests of Tiny RCU
         and Tiny SRCU; Optimize process_durations() operation;
 
         rcuscale: Dump stacks of stalled rcu_scale_writer() instances;
         dump grace-period statistics when rcu_scale_writer() stalls;
         mark idle RCU-barrier callbacks to identify stuck RCU-barrier
         callbacks; print detailed grace-period and barrier diagnostics
         on rcu_scale_writer() hangs for Tasks-RCU variants; warn if
         async module parameter is specified for RCU implementations
         that do not have async primitives such as RCU Tasks Rude;
         make all writer tasks report upon hang; tolerate repeated
         GFP_KERNEL failure in rcu_scale_writer(); use special allocator
         for rcu_scale_writer(); NULL out top-level pointers to heap
         memory to avoid double-free bugs on modprobe failures; maintain
         per-task instead of per-CPU callbacks count to avoid any issues
         with migration of either tasks or callbacks; constify struct
         ref_scale_ops.
 
 fixes.12.08.24a: Use system_unbound_wq for kfree_rcu work to avoid
         disturbing isolated CPUs.
 
 misc.11.08.24a: Warn on unexpected rcu_state.srs_done_tail state;
         Better define "atomic" for list_replace_rcu() and
         hlist_replace_rcu() routines; annotate struct
         kvfree_rcu_bulk_data with __counted_by().
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQSi2tPIQIc2VEtjarIAHS7/6Z0wpQUCZt8+8wAKCRAAHS7/6Z0w
 pTqoAPwPN//tlEoJx2PRs6t0q+nD1YNvnZawPaRmdzgdM8zJogD+PiSN+XhqRr80
 jzyvMDU4Aa0wjUNP3XsCoaCxo7L/lQk=
 =bZ9z
 -----END PGP SIGNATURE-----

Merge tag 'rcu.release.v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux

Pull RCU updates from Neeraj Upadhyay:
 "Context tracking:
   - rename context tracking state related symbols and remove references
     to "dynticks" in various context tracking state variables and
     related helpers
   - force context_tracking_enabled_this_cpu() to be inlined to avoid
     leaving a noinstr section

  CSD lock:
   - enhance CSD-lock diagnostic reports
   - add an API to provide an indication of ongoing CSD-lock stall

  nocb:
   - update and simplify RCU nocb code to handle (de-)offloading of
     callbacks only for offline CPUs
   - fix RT throttling hrtimer being armed from offline CPU

  rcutorture:
   - remove redundant rcu_torture_ops get_gp_completed fields
   - add SRCU ->same_gp_state and ->get_comp_state functions
   - add generic test for NUM_ACTIVE_*RCU_POLL* for testing RCU and SRCU
     polled grace periods
   - add CFcommon.arch for arch-specific Kconfig options
   - print number of update types in rcu_torture_write_types()
   - add rcutree.nohz_full_patience_delay testing to the TREE07 scenario
   - add a stall_cpu_repeat module parameter to test repeated CPU stalls
   - add argument to limit number of CPUs a guest OS can use in
     torture.sh

  rcustall:
   - abbreviate RCU CPU stall warnings during CSD-lock stalls
   - Allow dump_cpu_task() to be called without disabling preemption
   - defer printing stall-warning backtrace when holding rcu_node lock

  srcu:
   - make SRCU gp seq wrap-around faster
   - add KCSAN checks for concurrent updates to ->srcu_n_exp_nodelay and
     ->reschedule_count which are used in heuristics governing
     auto-expediting of normal SRCU grace periods and
     grace-period-state-machine delays
   - mark idle SRCU-barrier callbacks to help identify stuck
     SRCU-barrier callback

  rcu tasks:
   - remove RCU Tasks Rude asynchronous APIs as they are no longer used
   - stop testing RCU Tasks Rude asynchronous APIs
   - fix access to non-existent percpu regions
   - check processor-ID assumptions during chosen CPU calculation for
     callback enqueuing
   - update description of rtp->tasks_gp_seq grace-period sequence
     number
   - add rcu_barrier_cb_is_done() to identify whether a given
     rcu_barrier callback is stuck
   - mark idle Tasks-RCU-barrier callbacks
   - add *torture_stats_print() functions to print detailed diagnostics
     for Tasks-RCU variants
   - capture start time of rcu_barrier_tasks*() operation to help
     distinguish a hung barrier operation from a long series of barrier
     operations

  refscale:
   - add a TINY scenario to support tests of Tiny RCU and Tiny
     SRCU
   - optimize process_durations() operation

  rcuscale:
   - dump stacks of stalled rcu_scale_writer() instances and
     grace-period statistics when rcu_scale_writer() stalls
   - mark idle RCU-barrier callbacks to identify stuck RCU-barrier
     callbacks
   - print detailed grace-period and barrier diagnostics on
     rcu_scale_writer() hangs for Tasks-RCU variants
   - warn if async module parameter is specified for RCU implementations
     that do not have async primitives such as RCU Tasks Rude
   - make all writer tasks report upon hang
   - tolerate repeated GFP_KERNEL failure in rcu_scale_writer()
   - use special allocator for rcu_scale_writer()
   - NULL out top-level pointers to heap memory to avoid double-free
     bugs on modprobe failures
   - maintain per-task instead of per-CPU callbacks count to avoid any
     issues with migration of either tasks or callbacks
   - constify struct ref_scale_ops

  Fixes:
   - use system_unbound_wq for kfree_rcu work to avoid disturbing
     isolated CPUs

  Misc:
   - warn on unexpected rcu_state.srs_done_tail state
   - better define "atomic" for list_replace_rcu() and
     hlist_replace_rcu() routines
   - annotate struct kvfree_rcu_bulk_data with __counted_by()"

* tag 'rcu.release.v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (90 commits)
  rcu: Defer printing stall-warning backtrace when holding rcu_node lock
  rcu/nocb: Remove superfluous memory barrier after bypass enqueue
  rcu/nocb: Conditionally wake up rcuo if not already waiting on GP
  rcu/nocb: Fix RT throttling hrtimer armed from offline CPU
  rcu/nocb: Simplify (de-)offloading state machine
  context_tracking: Tag context_tracking_enabled_this_cpu() __always_inline
  context_tracking, rcu: Rename rcu_dyntick trace event into rcu_watching
  rcu: Update stray documentation references to rcu_dynticks_eqs_{enter, exit}()
  rcu: Rename rcu_momentary_dyntick_idle() into rcu_momentary_eqs()
  rcu: Rename rcu_implicit_dynticks_qs() into rcu_watching_snap_recheck()
  rcu: Rename dyntick_save_progress_counter() into rcu_watching_snap_save()
  rcu: Rename struct rcu_data .exp_dynticks_snap into .exp_watching_snap
  rcu: Rename struct rcu_data .dynticks_snap into .watching_snap
  rcu: Rename rcu_dynticks_zero_in_eqs() into rcu_watching_zero_in_eqs()
  rcu: Rename rcu_dynticks_in_eqs_since() into rcu_watching_snap_stopped_since()
  rcu: Rename rcu_dynticks_in_eqs() into rcu_watching_snap_in_eqs()
  rcu: Rename rcu_dynticks_eqs_online() into rcu_watching_online()
  context_tracking, rcu: Rename rcu_dynticks_curr_cpu_in_eqs() into rcu_is_watching_curr_cpu()
  context_tracking, rcu: Rename rcu_dynticks_task*() into rcu_task*()
  refscale: Constify struct ref_scale_ops
  ...
2024-09-18 07:52:24 +02:00
Linus Torvalds
9ea925c806 Updates for timers and timekeeping:
- Core:
 
 	- Overhaul of posix-timers in preparation of removing the
 	  workaround for periodic timers which have signal delivery
 	  ignored.
 
         - Remove the historical extra jiffie in msleep()
 
 	  msleep() adds an extra jiffie to the timeout value to ensure
 	  minimal sleep time. The timer wheel ensures minimal sleep
 	  time since the large rewrite to a non-cascading wheel, but the
 	  extra jiffie in msleep() remained unnoticed. Remove it.
 
         - Make the timer slack handling correct for realtime tasks.
 
 	  The procfs interface is inconsistent and does neither reflect
 	  reality nor conforms to the man page. Show the correct 0 slack
 	  for real time tasks and enforce it at the core level instead of
 	  having inconsistent individual checks in various timer setup
 	  functions.
 
         - The usual set of updates and enhancements all over the place.
 
   - Drivers:
 
         - Allow the ACPI PM timer to be turned off during suspend
 
 	- No new drivers
 
 	- The usual updates and enhancements in various drivers
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmbn7jQTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYobqnD/9COlU0nwsulABI/aNIrsh6iYvnCC9v
 14CcNta7Qn+157Wfw9BWOyHdNhR1/fPCXE8jJ71zTyIOeW27HV2JyTtxTwe9ZcdK
 ViHAaj7YcIjcVUEC3StCoRCPnvLslEw4qJA5AOQuDyMivdQn+YVa2c0baJxKaXZt
 xk4HZdMj4NAS0jRKnoZSwtKW/+Oz6rR4GAWrZo+Zs1/8ur3HfqnQfi8lJ1hJtLLW
 V7XDCVRvamVi6Ah3ocYPPp/1P6yeQDA1ge9aMddqaza5STWISXRtSnFMUmYP3rbS
 FaL8TyL+ilfny8pkGB2WlG6nLuSbtvogtdEh1gG1k1RmZt44kAtk8ba/KiWFPBSb
 zK9cjojRMBS71f9G4kmb5F4rnXoLsg1YbD1Nzhz3wq2Cs1Z90dc2QwMren0zoQ1x
 Fn56ueRyAiagBlnrSaKyso/2RvqJTNoSdi3RkpjYeAph0UoDCqvTvKjGAf1mWiw1
 T/1lUWSVqWHnzZbM7XXzzajIN9bl6A7bbqlcAJ2O9vZIDt7273DG+bQym9Vh6Why
 0LTGGERHxzKBsG7WRg+2Gmvv6S18UPKRo8tLtlA758rHlFuPTZCShWrIriwSNl1K
 Hxon+d4BparSnm1h9W/NHPKJA574UbWRCBjdk58IkAj8DxZZY4ORD9SMP+ggkV7G
 F6p9cgoDNP9KFg==
 =jE0N
 -----END PGP SIGNATURE-----

Merge tag 'timers-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "Core:

   - Overhaul of posix-timers in preparation of removing the workaround
     for periodic timers which have signal delivery ignored.

   - Remove the historical extra jiffie in msleep()

     msleep() adds an extra jiffie to the timeout value to ensure
     minimal sleep time. The timer wheel ensures minimal sleep time
     since the large rewrite to a non-cascading wheel, but the extra
     jiffie in msleep() remained unnoticed. Remove it.

   - Make the timer slack handling correct for realtime tasks.

     The procfs interface is inconsistent and does neither reflect
     reality nor conforms to the man page. Show the correct 0 slack for
     real time tasks and enforce it at the core level instead of having
     inconsistent individual checks in various timer setup functions.

   - The usual set of updates and enhancements all over the place.

  Drivers:

   - Allow the ACPI PM timer to be turned off during suspend

   - No new drivers

   - The usual updates and enhancements in various drivers"

* tag 'timers-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
  ntp: Make sure RTC is synchronized when time goes backwards
  treewide: Fix wrong singular form of jiffies in comments
  cpu: Use already existing usleep_range()
  timers: Rename next_expiry_recalc() to be unique
  platform/x86:intel/pmc: Fix comment for the pmc_core_acpi_pm_timer_suspend_resume function
  clocksource/drivers/jcore: Use request_percpu_irq()
  clocksource/drivers/cadence-ttc: Add missing clk_disable_unprepare in ttc_setup_clockevent
  clocksource/drivers/asm9260: Add missing clk_disable_unprepare in asm9260_timer_init
  clocksource/drivers/qcom: Add missing iounmap() on errors in msm_dt_timer_init()
  clocksource/drivers/ingenic: Use devm_clk_get_enabled() helpers
  platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended
  clocksource: acpi_pm: Add external callback for suspend/resume
  clocksource/drivers/arm_arch_timer: Using for_each_available_child_of_node_scoped()
  dt-bindings: timer: rockchip: Add rk3576 compatible
  timers: Annotate possible non critical data race of next_expiry
  timers: Remove historical extra jiffie for timeout in msleep()
  hrtimer: Use and report correct timerslack values for realtime tasks
  hrtimer: Annotate hrtimer_cpu_base_.*_expiry() for sparse.
  timers: Add sparse annotation for timer_sync_wait_running().
  signal: Replace BUG_ON()s
  ...
2024-09-17 07:25:37 +02:00
Linus Torvalds
cb69d86550 Updates for the interrupt subsystem:
- Core:
 	- Remove a global lock in the affinity setting code
 
 	  The lock protects a cpumask for intermediate results and the lock
 	  causes a bottleneck on simultaneous start of multiple virtual
 	  machines. Replace the lock and the static cpumask with a per CPU
 	  cpumask which is nicely serialized by raw spinlock held when
 	  executing this code.
 
 	- Provide support for giving a suffix to interrupt domain names.
 
 	  That's required to support devices with subfunctions so that the
 	  domain names are distinct even if they originate from the same
 	  device node.
 
 	- The usual set of cleanups and enhancements all over the place
 
   - Drivers:
 
 	- Support for longarch AVEC interrupt chip
 
 	- Refurbishment of the Armada driver so it can be extended for new
           variants.
 
 	- The usual set of cleanups and enhancements all over the place
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmbn5p8THHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoRFtD/43eB3h5usY2OPW0JmDqrE6qnzsvjPZ
 1H52BcmMcOuI6yCfTnbi/fBB52mwSEGq9Dmt1GXradyq9/CJDIqZ1ajI1rA2jzW2
 YdbeTDpKm1rS2ddzfp2LT2BryrNt+7etrRO7qHn4EKSuOcNuV2f58WPbIIqasvaK
 uPbUDVDPrvXxLNcjoab6SqaKrEoAaHSyKpd0MvDd80wHrtcSC/QouW7JDSUXv699
 RwvLebN1OF6mQ2J8Z3DLeCQpcbAs+UT8UvID7kYUJi1g71J/ZY+xpMLoX/gHiDNr
 isBtsuEAiZeNaFpksc7A6Jgu5ljZf2/aLCqbPLlHaduHFNmo94x9KUbIF2cpEMN+
 rsf5Ff7AVh1otz3cUwLLsm+cFLWRRoZdLuncn7rrgB4Yg0gll7qzyLO6YGvQHr8U
 Ocj1RXtvvWsMk4XzhgCt1AH/42cO6go+bhA4HspeYykNpsIldIUl1MeFbO8sWiDJ
 kybuwiwHp3oaMLjEK4Lpq65u7Ll8Lju2zRde65YUJN2nbNmJFORrOLmeC1qsr6ri
 dpend6n2qD9UD1oAt32ej/uXnG160nm7UKescyxiZNeTm1+ez8GW31hY128ifTY3
 4R3urGS38p3gazXBsfw6eqkeKx0kEoDNoQqrO5gBvb8kowYTvoZtkwMGAN9OADwj
 w6vvU0i+NIyVMA==
 =JlJ2
 -----END PGP SIGNATURE-----

Merge tag 'irq-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "Core:

   - Remove a global lock in the affinity setting code

     The lock protects a cpumask for intermediate results and the lock
     causes a bottleneck on simultaneous start of multiple virtual
     machines. Replace the lock and the static cpumask with a per CPU
     cpumask which is nicely serialized by raw spinlock held when
     executing this code.

   - Provide support for giving a suffix to interrupt domain names.

     That's required to support devices with subfunctions so that the
     domain names are distinct even if they originate from the same
     device node.

   - The usual set of cleanups and enhancements all over the place

  Drivers:

   - Support for longarch AVEC interrupt chip

   - Refurbishment of the Armada driver so it can be extended for new
     variants.

   - The usual set of cleanups and enhancements all over the place"

* tag 'irq-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (73 commits)
  genirq: Use cpumask_intersects()
  genirq/cpuhotplug: Use cpumask_intersects()
  irqchip/apple-aic: Only access system registers on SoCs which provide them
  irqchip/apple-aic: Add a new "Global fast IPIs only" feature level
  irqchip/apple-aic: Skip unnecessary enabling of use_fast_ipi
  dt-bindings: apple,aic: Document A7-A11 compatibles
  irqdomain: Use IS_ERR_OR_NULL() in irq_domain_trim_hierarchy()
  genirq/msi: Use kmemdup_array() instead of kmemdup()
  genirq/proc: Change the return value for set affinity permission error
  genirq/proc: Use irq_move_pending() in show_irq_affinity()
  genirq/proc: Correctly set file permissions for affinity control files
  genirq: Get rid of global lock in irq_do_set_affinity()
  genirq: Fix typo in struct comment
  irqchip/loongarch-avec: Add AVEC irqchip support
  irqchip/loongson-pch-msi: Prepare get_pch_msi_handle() for AVECINTC
  irqchip/loongson-eiointc: Rename CPUHP_AP_IRQ_LOONGARCH_STARTING
  LoongArch: Architectural preparation for AVEC irqchip
  LoongArch: Move irqchip function prototypes to irq-loongson.h
  irqchip/loongson-pch-msi: Switch to MSI parent domains
  softirq: Remove unused 'action' parameter from action callback
  ...
2024-09-17 07:09:17 +02:00
Tejun Heo
902d67a2d4 sched: Move update_other_load_avgs() to kernel/sched/pelt.c
96fd6c65ef ("sched: Factor out update_other_load_avgs() from
__update_blocked_others()") added update_other_load_avgs() in
kernel/sched/syscalls.c right above effective_cpu_util(). This location
didn't fit that well in the first place, and with 5d871a6399 ("sched/fair:
Move effective_cpu_util() and effective_cpu_util() in fair.c") moving
effective_cpu_util() to kernel/sched/fair.c, it looks even more out of
place.

Relocate the function to kernel/sched/pelt.c where all its callees are.

No functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
2024-09-11 20:00:21 -10:00
Tejun Heo
0b1777f0fa Merge branch 'tip/sched/core' into sched_ext/for-6.12
Pull in tip/sched/core to resolve two merge conflicts:

- 96fd6c65ef ("sched: Factor out update_other_load_avgs() from __update_blocked_others()")
  5d871a6399 ("sched/fair: Move effective_cpu_util() and effective_cpu_util() in fair.c")

  A simple context conflict. The former added __update_blocked_others() in
  the same #ifdef CONFIG_SMP block that effective_cpu_util() and
  sched_cpu_util() are in and the latter moved those functions to fair.c.
  This makes __update_blocked_others() more out of place. Will follow up
  with a patch to relocate.

- 96fd6c65ef ("sched: Factor out update_other_load_avgs() from __update_blocked_others()")
  84d265281d ("sched/pelt: Use rq_clock_task() for hw_pressure")

  The former factored out the body of __update_blocked_others() into
  update_other_load_avgs(). The latter changed how update_hw_load_avg() is
  called in the body. Resolved by applying the change to
  update_other_load_avgs() instead.

Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-11 08:43:26 -10:00
Christian Loehle
bc9057da1a sched/cpufreq: Use NSEC_PER_MSEC for deadline task
Convert the sugov deadline task attributes to use the available
definitions to make them more readable.
No functional change.

Signed-off-by: Christian Loehle <christian.loehle@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20240813144348.1180344-5-christian.loehle@arm.com
2024-09-11 11:25:22 +02:00
Tejun Heo
513ed0c7cc sched_ext: Don't trigger ops.quiescent/runnable() on migrations
A task moving across CPUs should not trigger quiescent/runnable task state
events as the task is staying runnable the whole time and just stopping and
then starting on different CPUs. Suppress quiescent/runnable task state
events if task_on_rq_migrating().

Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: David Vernet <void@manifault.com>
Cc: Daniel Hodges <hodges.daniel.scott@gmail.com>
Cc: Changwoo Min <multics69@gmail.com>
Cc: Andrea Righi <andrea.righi@linux.dev>
Cc: Dan Schatzberg <schatzberg.dan@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-10 10:45:20 -10:00
Tejun Heo
750a40d816 sched_ext: Synchronize bypass state changes with rq lock
While the BPF scheduler is being unloaded, the following warning messages
trigger sometimes:

 NOHZ tick-stop error: local softirq work is pending, handler #80!!!

This is caused by the CPU entering idle while there are pending softirqs.
The main culprit is the bypassing state assertion not being synchronized
with rq operations. As the BPF scheduler cannot be trusted in the disable
path, the first step is entering the bypass mode where the BPF scheduler is
ignored and scheduling becomes global FIFO.

This is implemented by turning scx_ops_bypassing() true. However, the
transition isn't synchronized against anything and it's possible for enqueue
and dispatch paths to have different ideas on whether bypass mode is on.

Make each rq track its own bypass state with SCX_RQ_BYPASSING which is
modified while rq is locked.

This removes most of the NOHZ tick-stop messages but not completely. I
believe the stragglers are from the sched core bug where pick_task_scx() can
be called without preceding balance_scx(). Once that bug is fixed, we should
verify that all occurrences of this error message are gone too.

v2: scx_enabled() test moved inside the for_each_possible_cpu() loop so that
    the per-cpu states are always synchronized with the global state.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: David Vernet <void@manifault.com>
2024-09-10 10:43:32 -10:00
Thomas Gleixner
2f7eedca6c Merge branch 'linus' into timers/core
To update with the latest fixes.
2024-09-10 13:49:53 +02:00
Huang Shijie
2cab4bd024 sched/debug: Fix the runnable tasks output
The current runnable tasks output looks like:

  runnable tasks:
   S            task   PID         tree-key  switches  prio     wait-time             sum-exec        sum-sleep
  -------------------------------------------------------------------------------------------------------------
   Ikworker/R-rcu_g     4         0.129049 E         0.620179           0.750000         0.002920         2   100         0.000000         0.002920         0.000000         0.000000 0 0 /
   Ikworker/R-sync_     5         0.125328 E         0.624147           0.750000         0.001840         2   100         0.000000         0.001840         0.000000         0.000000 0 0 /
   Ikworker/R-slub_     6         0.120835 E         0.628680           0.750000         0.001800         2   100         0.000000         0.001800         0.000000         0.000000 0 0 /
   Ikworker/R-netns     7         0.114294 E         0.634701           0.750000         0.002400         2   100         0.000000         0.002400         0.000000         0.000000 0 0 /
   I    kworker/0:1     9       508.781746 E       511.754666           3.000000       151.575240       224   120         0.000000       151.575240         0.000000         0.000000 0 0 /

Which is messy. Remove the duplicate printing of sum_exec_runtime and
tidy up the layout to make it look like:

  runnable tasks:
   S            task   PID       vruntime   eligible    deadline             slice          sum-exec      switches  prio         wait-time        sum-sleep       sum-block  node   group-id  group-path
  -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
   I     kworker/0:3  1698       295.001459   E         297.977619           3.000000        38.862920         9     120         0.000000         0.000000         0.000000   0      0        /
   I     kworker/0:4  1702       278.026303   E         281.026303           3.000000         9.918760         3     120         0.000000         0.000000         0.000000   0      0        /
   S  NetworkManager  2646         0.377936   E           2.598104           3.000000        98.535880       314     120         0.000000         0.000000         0.000000   0      0        /system.slice/NetworkManager.service
   S       virtqemud  2689         0.541016   E           2.440104           3.000000        50.967960        80     120         0.000000         0.000000         0.000000   0      0        /system.slice/virtqemud.service
   S   gsd-smartcard  3058        73.604144   E          76.475904           3.000000        74.033320        88     120         0.000000         0.000000         0.000000   0      0        /user.slice/user-42.slice/session-c1.scope

Reviewed-by: Christoph Lameter (Ampere) <cl@linux.com>
Signed-off-by: Huang Shijie <shijie@os.amperecomputing.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20240906053019.7874-1-shijie@os.amperecomputing.com
2024-09-10 09:51:15 +02:00
Peter Zijlstra
c662e2b1e8 sched: Fix sched_delayed vs sched_core
Completely analogous to commit dfa0a574cb ("sched/uclamg: Handle
delayed dequeue"), avoid double dequeue for the sched_core entries.

Fixes: 152e11f6df ("sched/fair: Implement delayed dequeue")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2024-09-10 09:51:15 +02:00
Dietmar Eggemann
729288bc68 kernel/sched: Fix util_est accounting for DELAY_DEQUEUE
Remove delayed tasks from util_est even they are runnable.

Exclude delayed task which are (a) migrating between rq's or (b) in a
SAVE/RESTORE dequeue/enqueue.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/c49ef5fe-a909-43f1-b02f-a765ab9cedbf@arm.com
2024-09-10 09:51:15 +02:00
Chen Yu
84d265281d sched/pelt: Use rq_clock_task() for hw_pressure
commit 97450eb909 ("sched/pelt: Remove shift of thermal clock")
removed the decay_shift for hw_pressure. This commit uses the
sched_clock_task() in sched_tick() while it replaces the
sched_clock_task() with rq_clock_pelt() in __update_blocked_others().
This could bring inconsistence. One possible scenario I can think of
is in ___update_load_sum():

  u64 delta = now - sa->last_update_time

'now' could be calculated by rq_clock_pelt() from
__update_blocked_others(), and last_update_time was calculated by
rq_clock_task() previously from sched_tick(). Usually the former
chases after the latter, it cause a very large 'delta' and brings
unexpected behavior.

Fixes: 97450eb909 ("sched/pelt: Remove shift of thermal clock")
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Hongyan Xia <hongyan.xia2@arm.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20240827112607.181206-1-yu.c.chen@intel.com
2024-09-10 09:51:14 +02:00
Vincent Guittot
5d871a6399 sched/fair: Move effective_cpu_util() and effective_cpu_util() in fair.c
Move effective_cpu_util() and sched_cpu_util() functions in fair.c file
with others utilization related functions.

No functional change.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20240904092417.20660-1-vincent.guittot@linaro.org
2024-09-10 09:51:14 +02:00
Peter Zijlstra
3dcac251b0 sched/core: Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
Since commit b2a02fc43a ("smp: Optimize
send_call_function_single_ipi()") an idle CPU in TIF_POLLING_NRFLAG mode
can be pulled out of idle by setting TIF_NEED_RESCHED flag to service an
IPI without actually sending an interrupt. Even in cases where the IPI
handler does not queue a task on the idle CPU, do_idle() will call
__schedule() since need_resched() returns true in these cases.

Introduce and use SM_IDLE to identify call to __schedule() from
schedule_idle() and shorten the idle re-entry time by skipping
pick_next_task() when nr_running is 0 and the previous task is the idle
task.

With the SM_IDLE fast-path, the time taken to complete a fixed set of
IPIs using ipistorm improves noticeably. Following are the numbers
from a dual socket Intel Ice Lake Xeon server (2 x 32C/64T) and
3rd Generation AMD EPYC system (2 x 64C/128T) (boost on, C2 disabled)
running ipistorm between CPU8 and CPU16:

cmdline: insmod ipistorm.ko numipi=100000 single=1 offset=8 cpulist=8 wait=1

   ==================================================================
   Test          : ipistorm (modified)
   Units         : Normalized runtime
   Interpretation: Lower is better
   Statistic     : AMean
   ======================= Intel Ice Lake Xeon ======================
   kernel:				time [pct imp]
   tip:sched/core			1.00 [baseline]
   tip:sched/core + SM_IDLE		0.80 [20.51%]
   ==================== 3rd Generation AMD EPYC =====================
   kernel:				time [pct imp]
   tip:sched/core			1.00 [baseline]
   tip:sched/core + SM_IDLE		0.90 [10.17%]
   ==================================================================

[ kprateek: Commit message, SM_RTLOCK_WAIT fix ]

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Not-yet-signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20240809092240.6921-1-kprateek.nayak@amd.com
2024-09-10 09:51:14 +02:00
Tejun Heo
4c30f5ce4f sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq()
Once a task is put into a DSQ, the allowed operations are fairly limited.
Tasks in the built-in local and global DSQs are executed automatically and,
ignoring dequeue, there is only one way a task in a user DSQ can be
manipulated - scx_bpf_consume() moves the first task to the dispatching
local DSQ. This inflexibility sometimes gets in the way and is an area where
multiple feature requests have been made.

Implement scx_bpf_dispatch[_vtime]_from_dsq(), which can be called during
DSQ iteration and can move the task to any DSQ - local DSQs, global DSQ and
user DSQs. The kfuncs can be called from ops.dispatch() and any BPF context
which dosen't hold a rq lock including BPF timers and SYSCALL programs.

This is an expansion of an earlier patch which only allowed moving into the
dispatching local DSQ:

  http://lkml.kernel.org/r/Zn4Cw4FDTmvXnhaf@slm.duckdns.org

v2: Remove @slice and @vtime from scx_bpf_dispatch_from_dsq[_vtime]() as
    they push scx_bpf_dispatch_from_dsq_vtime() over the kfunc argument
    count limit and often won't be needed anyway. Instead provide
    scx_bpf_dispatch_from_dsq_set_{slice|vtime}() kfuncs which can be called
    only when needed and override the specified parameter for the subsequent
    dispatch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Daniel Hodges <hodges.daniel.scott@gmail.com>
Cc: David Vernet <void@manifault.com>
Cc: Changwoo Min <multics69@gmail.com>
Cc: Andrea Righi <andrea.righi@linux.dev>
Cc: Dan Schatzberg <schatzberg.dan@gmail.com>
2024-09-09 13:42:47 -10:00
Tejun Heo
6462dd53a2 sched_ext: Compact struct bpf_iter_scx_dsq_kern
struct scx_iter_scx_dsq is defined as 6 u64's and scx_dsq_iter_kern was
using 5 of them. We want to add two more u64 fields but it's better if we do
so while staying within scx_iter_scx_dsq to maintain binary compatibility.

The way scx_iter_scx_dsq_kern is laid out is rather inefficient - the node
field takes up three u64's but only one bit of the last u64 is used. Turn
the bool into u32 flags and only use the lower 16 bits freeing up 48 bits -
16 bits for flags, 32 bits for a u32 - for use by struct
bpf_iter_scx_dsq_kern.

This allows moving the dsq_seq and flags fields of bpf_iter_scx_dsq_kern
into the cursor field reducing the struct size by a full u64.

No behavior changes intended.

Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-09 13:42:47 -10:00
Tejun Heo
cf3e94430d sched_ext: Replace consume_local_task() with move_local_task_to_local_dsq()
- Rename move_task_to_local_dsq() to move_remote_task_to_local_dsq().

- Rename consume_local_task() to move_local_task_to_local_dsq() and remove
  task_unlink_from_dsq() and source DSQ unlocking from it.

This is to make the migration code easier to reuse.

No functional changes intended.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-09-09 13:42:47 -10:00
Tejun Heo
d434210e13 sched_ext: Move consume_local_task() upward
So that the local case comes first and two CONFIG_SMP blocks can be merged.

No functional changes intended.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-09-09 13:42:47 -10:00
Tejun Heo
6557133ecd sched_ext: Move sanity check and dsq_mod_nr() into task_unlink_from_dsq()
All task_unlink_from_dsq() users are doing dsq_mod_nr(dsq, -1). Move it into
task_unlink_from_dsq(). Also move sanity check into it.

No functional changes intended.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-09-09 13:42:47 -10:00
Tejun Heo
1389f49098 sched_ext: Reorder args for consume_local/remote_task()
Reorder args for consistency in the order of:

  current_rq, p, src_[rq|dsq], dst_[rq|dsq].

No functional changes intended.

Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-09 13:42:47 -10:00