Commit Graph

64 Commits

Author SHA1 Message Date
Michel Lespinasse
c1e8d7c6a7 mmap locking API: convert mmap_sem comments
Convert comments that reference mmap_sem to reference mmap_lock instead.

[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:14 -07:00
Waiman Long
0c05b9bdbf docs: cgroup-v1: Document the cpuset_v2_mode mount option
The cpuset in cgroup v1 accepts a special "cpuset_v2_mode" mount
option that make cpuset.cpus and cpuset.mems behave more like those in
cgroup v2.  Document it to make other people more aware of this feature
that can be useful in some circumstances.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-04-03 11:42:56 -04:00
Tejun Heo
2b729fe7f3 Revert "cpuset: Make cpuset hotplug synchronous"
This reverts commit a49e4629b5 ("cpuset: Make cpuset hotplug synchronous") as
it may deadlock with cpu hotplug path.

Link: http://lkml.kernel.org/r/F0388D99-84D7-453B-9B6B-EEFF0E7BE4CC@lca.pw
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Qian Cai <cai@lca.pw>
Cc: Prateek Sood <prsood@codeaurora.org>
2020-04-03 11:32:13 -04:00
Prateek Sood
a49e4629b5 cpuset: Make cpuset hotplug synchronous
Convert cpuset_hotplug_workfn() into synchronous call for cpu hotplug
path. For memory hotplug path it still gets queued as a work item.

Since cpuset_hotplug_workfn() can be made synchronous for cpu hotplug
path, it is not required to wait for cpuset hotplug while thawing
processes.

Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-02-12 17:13:47 -05:00
Linus Torvalds
1b96a41b42 Merge branch 'for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "There are several notable changes here:

   - Single thread migrating itself has been optimized so that it
     doesn't need threadgroup rwsem anymore.

   - Freezer optimization to avoid unnecessary frozen state changes.

   - cgroup ID unification so that cgroup fs ino is the only unique ID
     used for the cgroup and can be used to directly look up live
     cgroups through filehandle interface on 64bit ino archs. On 32bit
     archs, cgroup fs ino is still the only ID in use but it is only
     unique when combined with gen.

   - selftest and other changes"

* 'for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (24 commits)
  writeback: fix -Wformat compilation warnings
  docs: cgroup: mm: Fix spelling of "list"
  cgroup: fix incorrect WARN_ON_ONCE() in cgroup_setup_root()
  cgroup: use cgrp->kn->id as the cgroup ID
  kernfs: use 64bit inos if ino_t is 64bit
  kernfs: implement custom exportfs ops and fid type
  kernfs: combine ino/id lookup functions into kernfs_find_and_get_node_by_id()
  kernfs: convert kernfs_node->id from union kernfs_node_id to u64
  kernfs: kernfs_find_and_get_node_by_ino() should only look up activated nodes
  kernfs: use dumber locking for kernfs_find_and_get_node_by_ino()
  netprio: use css ID instead of cgroup ID
  writeback: use ino_t for inodes in tracepoints
  kernfs: fix ino wrap-around detection
  kselftests: cgroup: Avoid the reuse of fd after it is deallocated
  cgroup: freezer: don't change task and cgroups status unnecessarily
  cgroup: use cgroup->last_bstat instead of cgroup->bstat_pending for consistency
  cgroup: remove cgroup_enable_task_cg_lists() optimization
  cgroup: pids: use atomic64_t for pids->limit
  selftests: cgroup: Run test_core under interfering stress
  selftests: cgroup: Add task migration tests
  ...
2019-11-25 19:23:46 -08:00
Valentin Schneider
cd1cb33505 sched/topology: Don't try to build empty sched domains
Turns out hotplugging CPUs that are in exclusive cpusets can lead to the
cpuset code feeding empty cpumasks to the sched domain rebuild machinery.

This leads to the following splat:

    Internal error: Oops: 96000004 [#1] PREEMPT SMP
    Modules linked in:
    CPU: 0 PID: 235 Comm: kworker/5:2 Not tainted 5.4.0-rc1-00005-g8d495477d62e #23
    Hardware name: ARM Juno development board (r0) (DT)
    Workqueue: events cpuset_hotplug_workfn
    pstate: 60000005 (nZCv daif -PAN -UAO)
    pc : build_sched_domains (./include/linux/arch_topology.h:23 kernel/sched/topology.c:1898 kernel/sched/topology.c:1969)
    lr : build_sched_domains (kernel/sched/topology.c:1966)
    Call trace:
    build_sched_domains (./include/linux/arch_topology.h:23 kernel/sched/topology.c:1898 kernel/sched/topology.c:1969)
    partition_sched_domains_locked (kernel/sched/topology.c:2250)
    rebuild_sched_domains_locked (./include/linux/bitmap.h:370 ./include/linux/cpumask.h:538 kernel/cgroup/cpuset.c:955 kernel/cgroup/cpuset.c:978 kernel/cgroup/cpuset.c:1019)
    rebuild_sched_domains (kernel/cgroup/cpuset.c:1032)
    cpuset_hotplug_workfn (kernel/cgroup/cpuset.c:3205 (discriminator 2))
    process_one_work (./arch/arm64/include/asm/jump_label.h:21 ./include/linux/jump_label.h:200 ./include/trace/events/workqueue.h:114 kernel/workqueue.c:2274)
    worker_thread (./include/linux/compiler.h:199 ./include/linux/list.h:268 kernel/workqueue.c:2416)
    kthread (kernel/kthread.c:255)
    ret_from_fork (arch/arm64/kernel/entry.S:1167)
    Code: f860dae2 912802d6 aa1603e1 12800000 (f8616853)

The faulty line in question is:

  cap = arch_scale_cpu_capacity(cpumask_first(cpu_map));

and we're not checking the return value against nr_cpu_ids (we shouldn't
have to!), which leads to the above.

Prevent generate_sched_domains() from returning empty cpumasks, and add
some assertion in build_sched_domains() to scream bloody murder if it
happens again.

The above splat was obtained on my Juno r0 with the following reproducer:

  $ cgcreate -g cpuset:asym
  $ cgset -r cpuset.cpus=0-3 asym
  $ cgset -r cpuset.mems=0 asym
  $ cgset -r cpuset.cpu_exclusive=1 asym

  $ cgcreate -g cpuset:smp
  $ cgset -r cpuset.cpus=4-5 smp
  $ cgset -r cpuset.mems=0 smp
  $ cgset -r cpuset.cpu_exclusive=1 smp

  $ cgset -r cpuset.sched_load_balance=0 .

  $ echo 0 > /sys/devices/system/cpu/cpu4/online
  $ echo 0 > /sys/devices/system/cpu/cpu5/online

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dietmar.Eggemann@arm.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: hannes@cmpxchg.org
Cc: lizefan@huawei.com
Cc: morten.rasmussen@arm.com
Cc: qperret@google.com
Cc: tj@kernel.org
Cc: vincent.guittot@linaro.org
Fixes: 05484e0984 ("sched/topology: Add SD_ASYM_CPUCAPACITY flag detection")
Link: https://lkml.kernel.org/r/20191023153745.19515-2-valentin.schneider@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-29 09:58:45 +01:00
Tejun Heo
5153faac18 cgroup: remove cgroup_enable_task_cg_lists() optimization
cgroup_enable_task_cg_lists() is used to lazyily initialize task
cgroup associations on the first use to reduce fork / exit overheads
on systems which don't use cgroup.  Unfortunately, locking around it
has never been actually correct and its value is dubious given how the
vast majority of systems use cgroup right away from boot.

This patch removes the optimization.  For now, replace the cg_list
based branches with WARN_ON_ONCE()'s to be on the safe side.  We can
simplify the logic further in the future.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2019-10-25 05:56:28 -07:00
Juri Lelli
710da3c8ea sched/core: Prevent race condition between cpuset and __sched_setscheduler()
No synchronisation mechanism exists between the cpuset subsystem and
calls to function __sched_setscheduler(). As such, it is possible that
new root domains are created on the cpuset side while a deadline
acceptance test is carried out in __sched_setscheduler(), leading to a
potential oversell of CPU bandwidth.

Grab cpuset_rwsem read lock from core scheduler, so to prevent
situations such as the one described above from happening.

The only exception is normalize_rt_tasks() which needs to work under
tasklist_lock and can't therefore grab cpuset_rwsem. We are fine with
this, as this function is only called by sysrq and, if that gets
triggered, DEADLINE guarantees are already gone out of the window
anyway.

Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bristot@redhat.com
Cc: claudio@evidence.eu.com
Cc: lizefan@huawei.com
Cc: longman@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: mathieu.poirier@linaro.org
Cc: rostedt@goodmis.org
Cc: tj@kernel.org
Cc: tommaso.cucinotta@santannapisa.it
Link: https://lkml.kernel.org/r/20190719140000.31694-9-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:55:04 +02:00
Juri Lelli
d74b27d63a cgroup/cpuset: Change cpuset_rwsem and hotplug lock order
cpuset_rwsem is going to be acquired from sched_setscheduler() with a
following patch. There are however paths (e.g., spawn_ksoftirqd) in
which sched_scheduler() is eventually called while holding hotplug lock;
this creates a dependecy between hotplug lock (to be always acquired
first) and cpuset_rwsem (to be always acquired after hotplug lock).

Fix paths which currently take the two locks in the wrong order (after
a following patch is applied).

Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bristot@redhat.com
Cc: claudio@evidence.eu.com
Cc: lizefan@huawei.com
Cc: longman@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: mathieu.poirier@linaro.org
Cc: rostedt@goodmis.org
Cc: tj@kernel.org
Cc: tommaso.cucinotta@santannapisa.it
Link: https://lkml.kernel.org/r/20190719140000.31694-7-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:55:03 +02:00
Juri Lelli
1243dc518c cgroup/cpuset: Convert cpuset_mutex to percpu_rwsem
Holding cpuset_mutex means that cpusets are stable (only the holder can
make changes) and this is required for fixing a synchronization issue
between cpusets and scheduler core.  However, grabbing cpuset_mutex from
setscheduler() hotpath (as implemented in a later patch) is a no-go, as
it would create a bottleneck for tasks concurrently calling
setscheduler().

Convert cpuset_mutex to be a percpu_rwsem (cpuset_rwsem), so that
setscheduler() will then be able to read lock it and avoid concurrency
issues.

Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bristot@redhat.com
Cc: claudio@evidence.eu.com
Cc: lizefan@huawei.com
Cc: longman@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: mathieu.poirier@linaro.org
Cc: rostedt@goodmis.org
Cc: tj@kernel.org
Cc: tommaso.cucinotta@santannapisa.it
Link: https://lkml.kernel.org/r/20190719140000.31694-6-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:55:02 +02:00
Mathieu Poirier
f9a25f776d cpusets: Rebuild root domain deadline accounting information
When the topology of root domains is modified by CPUset or CPUhotplug
operations information about the current deadline bandwidth held in the
root domain is lost.

This patch addresses the issue by recalculating the lost deadline
bandwidth information by circling through the deadline tasks held in
CPUsets and adding their current load to the root domain they are
associated with.

Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
[ Various additional modifications. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bristot@redhat.com
Cc: claudio@evidence.eu.com
Cc: lizefan@huawei.com
Cc: longman@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: rostedt@goodmis.org
Cc: tj@kernel.org
Cc: tommaso.cucinotta@santannapisa.it
Link: https://lkml.kernel.org/r/20190719140000.31694-4-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:55:01 +02:00
Linus Torvalds
933a90bf4f Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount updates from Al Viro:
 "The first part of mount updates.

  Convert filesystems to use the new mount API"

* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  mnt_init(): call shmem_init() unconditionally
  constify ksys_mount() string arguments
  don't bother with registering rootfs
  init_rootfs(): don't bother with init_ramfs_fs()
  vfs: Convert smackfs to use the new mount API
  vfs: Convert selinuxfs to use the new mount API
  vfs: Convert securityfs to use the new mount API
  vfs: Convert apparmorfs to use the new mount API
  vfs: Convert openpromfs to use the new mount API
  vfs: Convert xenfs to use the new mount API
  vfs: Convert gadgetfs to use the new mount API
  vfs: Convert oprofilefs to use the new mount API
  vfs: Convert ibmasmfs to use the new mount API
  vfs: Convert qib_fs/ipathfs to use the new mount API
  vfs: Convert efivarfs to use the new mount API
  vfs: Convert configfs to use the new mount API
  vfs: Convert binfmt_misc to use the new mount API
  convenience helper: get_tree_single()
  convenience helper get_tree_nodev()
  vfs: Kill sget_userns()
  ...
2019-07-19 10:42:02 -07:00
Mauro Carvalho Chehab
da82c92f11 docs: cgroup-v1: add it to the admin-guide book
Those files belong to the admin guide, so add them.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15 11:03:02 -03:00
Linus Torvalds
92c1d65221 Merge branch 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "Documentation updates and the addition of cgroup_parse_float() which
  will be used by new controllers including blk-iocost"

* 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  docs: cgroup-v1: convert docs to ReST and rename to *.rst
  cgroup: Move cgroup_parse_float() implementation out of CONFIG_SYSFS
  cgroup: add cgroup_parse_float()
2019-07-08 21:35:12 -07:00
Ingo Molnar
23da766ab1 Linux 5.2-rc5
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Merge tag 'v5.2-rc5' into sched/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-17 12:12:27 +02:00
Mauro Carvalho Chehab
99c8b231ae docs: cgroup-v1: convert docs to ReST and rename to *.rst
Convert the cgroup-v1 files to ReST format, in order to
allow a later addition to the admin-guide.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2019-06-14 13:29:54 -07:00
Joel Savitz
d477f8c202 cpuset: restore sanity to cpuset_cpus_allowed_fallback()
In the case that a process is constrained by taskset(1) (i.e.
sched_setaffinity(2)) to a subset of available cpus, and all of those are
subsequently offlined, the scheduler will set tsk->cpus_allowed to
the current value of task_cs(tsk)->effective_cpus.

This is done via a call to do_set_cpus_allowed() in the context of
cpuset_cpus_allowed_fallback() made by the scheduler when this case is
detected. This is the only call made to cpuset_cpus_allowed_fallback()
in the latest mainline kernel.

However, this is not sane behavior.

I will demonstrate this on a system running the latest upstream kernel
with the following initial configuration:

	# grep -i cpu /proc/$$/status
	Cpus_allowed:	ffffffff,fffffff
	Cpus_allowed_list:	0-63

(Where cpus 32-63 are provided via smt.)

If we limit our current shell process to cpu2 only and then offline it
and reonline it:

	# taskset -p 4 $$
	pid 2272's current affinity mask: ffffffffffffffff
	pid 2272's new affinity mask: 4

	# echo off > /sys/devices/system/cpu/cpu2/online
	# dmesg | tail -3
	[ 2195.866089] process 2272 (bash) no longer affine to cpu2
	[ 2195.872700] IRQ 114: no longer affine to CPU2
	[ 2195.879128] smpboot: CPU 2 is now offline

	# echo on > /sys/devices/system/cpu/cpu2/online
	# dmesg | tail -1
	[ 2617.043572] smpboot: Booting Node 0 Processor 2 APIC 0x4

We see that our current process now has an affinity mask containing
every cpu available on the system _except_ the one we originally
constrained it to:

	# grep -i cpu /proc/$$/status
	Cpus_allowed:   ffffffff,fffffffb
	Cpus_allowed_list:      0-1,3-63

This is not sane behavior, as the scheduler can now not only place the
process on previously forbidden cpus, it can't even schedule it on
the cpu it was originally constrained to!

Other cases result in even more exotic affinity masks. Take for instance
a process with an affinity mask containing only cpus provided by smt at
the moment that smt is toggled, in a configuration such as the following:

	# taskset -p f000000000 $$
	# grep -i cpu /proc/$$/status
	Cpus_allowed:	000000f0,00000000
	Cpus_allowed_list:	36-39

A double toggle of smt results in the following behavior:

	# echo off > /sys/devices/system/cpu/smt/control
	# echo on > /sys/devices/system/cpu/smt/control
	# grep -i cpus /proc/$$/status
	Cpus_allowed:	ffffff00,ffffffff
	Cpus_allowed_list:	0-31,40-63

This is even less sane than the previous case, as the new affinity mask
excludes all smt-provided cpus with ids less than those that were
previously in the affinity mask, as well as those that were actually in
the mask.

With this patch applied, both of these cases end in the following state:

	# grep -i cpu /proc/$$/status
	Cpus_allowed:	ffffffff,ffffffff
	Cpus_allowed_list:	0-63

The original policy is discarded. Though not ideal, it is the simplest way
to restore sanity to this fallback case without reinventing the cpuset
wheel that rolls down the kernel just fine in cgroup v2. A user who wishes
for the previous affinity mask to be restored in this fallback case can use
that mechanism instead.

This patch modifies scheduler behavior by instead resetting the mask to
task_cs(tsk)->cpus_allowed by default, and cpu_possible mask in legacy
mode. I tested the cases above on both modes.

Note that the scheduler uses this fallback mechanism if and only if
_every_ other valid avenue has been traveled, and it is the last resort
before calling BUG().

Suggested-by: Waiman Long <longman@redhat.com>
Suggested-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Acked-by: Phil Auld <pauld@redhat.com>
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2019-06-12 11:00:08 -07:00
Sebastian Andrzej Siewior
3bd3706251 sched/core: Provide a pointer to the valid CPU mask
In commit:

  4b53a3412d ("sched/core: Remove the tsk_nr_cpus_allowed() wrapper")

the tsk_nr_cpus_allowed() wrapper was removed. There was not
much difference in !RT but in RT we used this to implement
migrate_disable(). Within a migrate_disable() section the CPU mask is
restricted to single CPU while the "normal" CPU mask remains untouched.

As an alternative implementation Ingo suggested to use:

	struct task_struct {
		const cpumask_t		*cpus_ptr;
		cpumask_t		cpus_mask;
        };
with
	t->cpus_ptr = &t->cpus_mask;

In -RT we then can switch the cpus_ptr to:

	t->cpus_ptr = &cpumask_of(task_cpu(p));

in a migration disabled region. The rules are simple:

 - Code that 'uses' ->cpus_allowed would use the pointer.
 - Code that 'modifies' ->cpus_allowed would use the direct mask.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190423142636.14347-1-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-03 11:49:37 +02:00
Al Viro
d5f68d330c cpuset: move mount -t cpuset logics into cgroup.c
... and get rid of the weird dances in ->get_tree() - that logics
can be easily handled in ->init_fs_context().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-25 18:00:01 -04:00
Juri Lelli
b6fbbf31d1 cgroup/cpuset: Update stale generate_sched_domains() comments
Commit:

  fc560a26ac ("cpuset: replace cpuset->stack_list with cpuset_for_each_descendant_pre()")

removed the local list (q) that was used to perform a top-down scan
of all cpusets; however, comments mentioning it were not updated.

Update comments to reflect current implementation.

Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: cgroups@vger.kernel.org
Cc: lizefan@huawei.com
Link: http://lkml.kernel.org/r/20181219133445.31982-1-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-19 19:44:14 +02:00
Linus Torvalds
7b47a9e7c8 Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount infrastructure updates from Al Viro:
 "The rest of core infrastructure; no new syscalls in that pile, but the
  old parts are switched to new infrastructure. At that point
  conversions of individual filesystems can happen independently; some
  are done here (afs, cgroup, procfs, etc.), there's also a large series
  outside of that pile dealing with NFS (quite a bit of option-parsing
  stuff is getting used there - it's one of the most convoluted
  filesystems in terms of mount-related logics), but NFS bits are the
  next cycle fodder.

  It got seriously simplified since the last cycle; documentation is
  probably the weakest bit at the moment - I considered dropping the
  commit introducing Documentation/filesystems/mount_api.txt (cutting
  the size increase by quarter ;-), but decided that it would be better
  to fix it up after -rc1 instead.

  That pile allows to do followup work in independent branches, which
  should make life much easier for the next cycle. fs/super.c size
  increase is unpleasant; there's a followup series that allows to
  shrink it considerably, but I decided to leave that until the next
  cycle"

* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits)
  afs: Use fs_context to pass parameters over automount
  afs: Add fs_context support
  vfs: Add some logging to the core users of the fs_context log
  vfs: Implement logging through fs_context
  vfs: Provide documentation for new mount API
  vfs: Remove kern_mount_data()
  hugetlbfs: Convert to fs_context
  cpuset: Use fs_context
  kernfs, sysfs, cgroup, intel_rdt: Support fs_context
  cgroup: store a reference to cgroup_ns into cgroup_fs_context
  cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper
  cgroup_do_mount(): massage calling conventions
  cgroup: stash cgroup_root reference into cgroup_fs_context
  cgroup2: switch to option-by-option parsing
  cgroup1: switch to option-by-option parsing
  cgroup: take options parsing into ->parse_monolithic()
  cgroup: fold cgroup1_mount() into cgroup1_get_tree()
  cgroup: start switching to fs_context
  ipc: Convert mqueue fs to fs_context
  proc: Add fs_context support to procfs
  ...
2019-03-12 14:08:19 -07:00
David Howells
a187537473 cpuset: Use fs_context
Make the cpuset filesystem use the filesystem context.  This is potentially
tricky as the cpuset fs is almost an alias for the cgroup filesystem, but
with some special parameters.

This can, however, be handled by setting up an appropriate cgroup
filesystem and returning the root directory of that as the root dir of this
one.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-28 03:29:35 -05:00
Masahiro Yamada
6a613d24ef cpuset: remove unused task_has_mempolicy()
This is a remnant of commit 5f155f27cb ("mm, cpuset: always use
seqlock when changing task's nodemask").

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2019-02-19 06:26:02 -08:00
Linus Torvalds
6f9d71c9c7 Merge branch 'for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:

 - Waiman's cgroup2 cpuset support has been finally merged closing one
   of the last remaining feature gaps.

 - cgroup.procs could show non-leader threads when cgroup2 threaded mode
   was used in certain ways. I forgot to push the fix during the last
   cycle.

 - A patch to fix mount option parsing when all mount options have been
   consumed by someone else (LSM).

 - cgroup_no_v1 boot param can now block named cgroup1 hierarchies too.

* 'for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: Add named hierarchy disabling to cgroup_no_v1 boot param
  cgroup: fix parsing empty mount option string
  cpuset: Remove set but not used variable 'cs'
  cgroup: fix CSS_TASK_ITER_PROCS
  cgroup: Add .__DEBUG__. prefix to debug file names
  cpuset: Minor cgroup2 interface updates
  cpuset: Expose cpuset.cpus.subpartitions with cgroup_debug
  cpuset: Add documentation about the new "cpuset.sched.partition" flag
  cpuset: Use descriptive text when reading/writing cpuset.sched.partition
  cpuset: Expose cpus.effective and mems.effective on cgroup v2 root
  cpuset: Make generate_sched_domains() work with partition
  cpuset: Make CPU hotplug work with partition
  cpuset: Track cpusets that use parent's effective_cpus
  cpuset: Add an error state to cpuset.sched.partition
  cpuset: Add new v2 cpuset.sched.partition flag
  cpuset: Simply allocation and freeing of cpumasks
  cpuset: Define data structures to support scheduling partition
  cpuset: Enable cpuset controller in default hierarchy
  cgroup: remove unnecessary unlikely()
2018-12-29 10:57:20 -08:00
yuzhoujian
ef8444ea01 mm, oom: reorganize the oom report in dump_header
OOM report contains several sections.  The first one is the allocation
context that has triggered the OOM.  Then we have cpuset context followed
by the stack trace of the OOM path.  The tird one is the OOM memory
information.  Followed by the current memory state of all system tasks.
At last, we will show oom eligible tasks and the information about the
chosen oom victim.

One thing that makes parsing more awkward than necessary is that we do not
have a single and easily parsable line about the oom context.  This patch
is reorganizing the oom report to

1) who invoked oom and what was the allocation request

[  515.902945] tuned invoked oom-killer: gfp_mask=0x6200ca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=0

2) OOM stack trace

[  515.904273] CPU: 24 PID: 1809 Comm: tuned Not tainted 4.20.0-rc3+ #3
[  515.905518] Hardware name: Inspur SA5212M4/YZMB-00370-107, BIOS 4.1.10 11/14/2016
[  515.906821] Call Trace:
[  515.908062]  dump_stack+0x5a/0x73
[  515.909311]  dump_header+0x55/0x28c
[  515.914260]  oom_kill_process+0x2d8/0x300
[  515.916708]  out_of_memory+0x145/0x4a0
[  515.917932]  __alloc_pages_slowpath+0x7d2/0xa16
[  515.919157]  __alloc_pages_nodemask+0x277/0x290
[  515.920367]  filemap_fault+0x3d0/0x6c0
[  515.921529]  ? filemap_map_pages+0x2b8/0x420
[  515.922709]  ext4_filemap_fault+0x2c/0x40 [ext4]
[  515.923884]  __do_fault+0x20/0x80
[  515.925032]  __handle_mm_fault+0xbc0/0xe80
[  515.926195]  handle_mm_fault+0xfa/0x210
[  515.927357]  __do_page_fault+0x233/0x4c0
[  515.928506]  do_page_fault+0x32/0x140
[  515.929646]  ? page_fault+0x8/0x30
[  515.930770]  page_fault+0x1e/0x30

3) OOM memory information

[  515.958093] Mem-Info:
[  515.959647] active_anon:26501758 inactive_anon:1179809 isolated_anon:0
 active_file:4402672 inactive_file:483963 isolated_file:1344
 unevictable:0 dirty:4886753 writeback:0 unstable:0
 slab_reclaimable:148442 slab_unreclaimable:18741
 mapped:1347 shmem:1347 pagetables:58669 bounce:0
 free:88663 free_pcp:0 free_cma:0
...

4) current memory state of all system tasks

[  516.079544] [    744]     0   744     9211     1345   114688       82             0 systemd-journal
[  516.082034] [    787]     0   787    31764        0   143360       92             0 lvmetad
[  516.084465] [    792]     0   792    10930        1   110592      208         -1000 systemd-udevd
[  516.086865] [   1199]     0  1199    13866        0   131072      112         -1000 auditd
[  516.089190] [   1222]     0  1222    31990        1   110592      157             0 smartd
[  516.091477] [   1225]     0  1225     4864       85    81920       43             0 irqbalance
[  516.093712] [   1226]     0  1226    52612        0   258048      426             0 abrtd
[  516.112128] [   1280]     0  1280   109774       55   299008      400             0 NetworkManager
[  516.113998] [   1295]     0  1295    28817       37    69632       24             0 ksmtuned
[  516.144596] [  10718]     0 10718  2622484  1721372 15998976   267219             0 panic
[  516.145792] [  10719]     0 10719  2622484  1164767  9818112    53576             0 panic
[  516.146977] [  10720]     0 10720  2622484  1174361  9904128    53709             0 panic
[  516.148163] [  10721]     0 10721  2622484  1209070 10194944    54824             0 panic
[  516.149329] [  10722]     0 10722  2622484  1745799 14774272    91138             0 panic

5) oom context (contrains and the chosen victim).

oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0-1,task=panic,pid=10737,uid=0

An admin can easily get the full oom context at a single line which
makes parsing much easier.

Link: http://lkml.kernel.org/r/1542799799-36184-1-git-send-email-ufo19890607@gmail.com
Signed-off-by: yuzhoujian <yuzhoujian@didichuxing.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Yang Shi <yang.s@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 12:11:48 -08:00
YueHaibing
1e7eacaf1d cpuset: Remove set but not used variable 'cs'
Fixes gcc '-Wunused-but-set-variable' warning:

kernel/cgroup/cpuset.c: In function 'cpuset_cancel_attach':
kernel/cgroup/cpuset.c:2167:17: warning:
 variable 'cs' set but not used [-Wunused-but-set-variable]

It never used since introduction in commit 1f7dd3e5a6 ("cgroup: fix handling
of multi-destination migration from subtree_control enabling")

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-12-03 08:23:22 -08:00
Tejun Heo
b1e3aeb11c cpuset: Minor cgroup2 interface updates
* Rename the partition file from "cpuset.sched.partition" to
  "cpuset.cpus.partition".

* When writing to the partition file, drop "0" and "1" and only accept
  "member" and "root".

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>
2018-11-13 12:09:48 -08:00
Waiman Long
5cf8114d6e cpuset: Expose cpuset.cpus.subpartitions with cgroup_debug
For debugging purpose, it will be useful to expose the content of the
subparts_cpus as a read-only file to see if the code work correctly.
However, subparts_cpus will not be used at all in most use cases. So
adding a new cpuset file that clutters the cgroup directory may not be
desirable.  This is now being done by using the hidden "cgroup_debug"
kernel command line option to expose a new "cpuset.cpus.subpartitions"
file.

That option was originally used by the debug controller to expose
itself when configured into the kernel. This is now extended to set an
internal flag used by cgroup_addrm_files(). A new CFTYPE_DEBUG flag
can now be used to specify that a cgroup file should only be created
when the "cgroup_debug" option is specified.

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08 12:27:32 -08:00
Waiman Long
bb5b553c33 cpuset: Use descriptive text when reading/writing cpuset.sched.partition
Currently, cpuset.sched.partition returns the values, 0, 1 or -1 on
read. A person who is not familiar with the partition code may not
understand what they mean.

In order to make cpuset.sched.partition more user-friendly, it will
now display the following descriptive text on read:

  "root" - A partition root (top cpuset of a partition)
  "member" - A non-root member of a partition
  "root invalid" - An invalid partition root

Note that there is at least one partition in the whole cgroup hierarchy.
The top cpuset is the root of that partition.  The rests are either a
root if it starts a new partition or a member of a partition.

The cpuset.sched.partition file will now also accept "root" and
"member" besides 1 and 0 as valid input values. The "root invalid"
value is internal only and cannot be written to the file.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08 12:27:31 -08:00
Waiman Long
5776ceccd4 cpuset: Expose cpus.effective and mems.effective on cgroup v2 root
Because of the fact that setting the "cpuset.sched.partition" in
a direct child of root can remove CPUs from the root's effective CPU
list, it makes sense to know what CPUs are left in the root cgroup for
scheduling purpose. So the "cpuset.cpus.effective" control file is now
exposed in the v2 cgroup root.

For consistency, the "cpuset.mems.effective" control file is exposed
as well.

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08 12:27:31 -08:00
Waiman Long
0ccea8feb9 cpuset: Make generate_sched_domains() work with partition
The generate_sched_domains() function is modified to make it work
correctly with the newly introduced subparts_cpus mask for scheduling
domains generation.

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08 12:27:30 -08:00
Waiman Long
4b842da276 cpuset: Make CPU hotplug work with partition
When there is a cpu hotplug event (CPU online or offline), the partitions
may need to be reconfigured and regenerated. So code is added to the
hotplug functions to make them work with new subparts_cpus mask to
compute the right effective_cpus for each of the affected cpusets.
It may also change the state of a partition root from real one to an
erroneous one or vice versa.

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08 12:27:30 -08:00
Waiman Long
4716909cc5 cpuset: Track cpusets that use parent's effective_cpus
In the default hierarchy, a cpuset will use the parent's effective_cpus
if none of the requested CPUs can be granted from the parent. That can
be a problem if a parent is a partition root with children partition
roots. Changes to a parent's effective_cpus list due to changes in a
child partition root may not be properly reflected in a child cpuset
that use parent's effective_cpus because the cpu_exclusive rule of a
partition root will not guard against that.

In order to avoid the mismatch, two new tracking variables are added to
the cpuset structure to track if a cpuset uses parent's effective_cpus
and the number of children cpusets that use its effective_cpus. So
whenever cpumask changes are made to a parent, it will also check to
see if it has other children cpusets that use its effective_cpus and
call update_cpumasks_hier() if that is the case.

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08 12:27:29 -08:00
Waiman Long
3881b86128 cpuset: Add an error state to cpuset.sched.partition
When external events like CPU offlining or user events like changing
the cpu list of an ancestor cpuset happen, update_cpumasks_hier()
will be called to update the effective cpus of each of the affected
cpusets. That will then call update_parent_subparts_cpumask() if
partitions are impacted.

Currently, these events may cause update_parent_subparts_cpumask()
to return error if none of the requested cpus are available or it will
consume all the cpus in the parent partition root. Handling these errors
is problematic as the states may become inconsistent.

Instead of letting update_parent_subparts_cpumask() return error, a new
error state (-1) is added to the partition_root_state flag to designate
the fact that the partition is no longer valid. IOW, it is no longer a
real partition root, but the CS_CPU_EXCLUSIVE flag will still be set
as it can be changed back to a real one if favorable change happens
later on.

This new error state is set internally and user cannot write this new
value to "cpuset.sched.partition".

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08 12:27:29 -08:00
Waiman Long
ee8dde0cd2 cpuset: Add new v2 cpuset.sched.partition flag
A new cpuset.sched.partition boolean flag is added to cpuset v2.
This new flag, if set, indicates that the cgroup is the root of a
new scheduling domain or partition that includes itself and all its
descendants except those that are scheduling domain roots themselves
and their descendants.

With this new flag, one can directly create as many partitions as
necessary without ever using the v1 trick of turning off load balancing
in specific cpusets to create partitions as a side effect.

This new flag is owned by the parent and will cause the CPUs in the
cpuset to be removed from the effective CPUs of its parent.

This is implemented internally by adding a new subparts_cpus mask that
holds the CPUs belonging to child partitions so that:

        subparts_cpus | effective_cpus = cpus_allowed
        subparts_cpus & effective_cpus = 0

This new flag can only be turned on in a cpuset if its parent is a
partition root itself. The state of this flag cannot be changed if the
cpuset has children.

Once turned on, further changes to "cpuset.cpus" is allowed as long
as there is at least one CPU left that can be granted from the parent
and a child partition root cannot use up all the CPUs in the parent's
effective_cpus.

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08 12:27:28 -08:00
Waiman Long
bf92370c03 cpuset: Simply allocation and freeing of cpumasks
The previous commit introduces a new subparts_cpus mask into the cpuset
data structure and a new tmpmasks structure.  Managing the allocation
and freeing of those cpumasks is becoming more complex.

So a number of helper functions are added to simplify and streamline
the management of those cpumasks. To make it simple, all the cpumasks
are now pre-cleared on allocation.

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08 12:27:28 -08:00
Waiman Long
58b7484250 cpuset: Define data structures to support scheduling partition
>From a cpuset point of view, a scheduling partition is a group of
cpusets with their own set of exclusive CPUs that are not shared by
other tasks outside the scheduling partition.

In the legacy hierarchy, scheduling partitions are supported indirectly
via the right use of the load balancing and the exclusive CPUs flag
which is not intuitive and can be hard to use.

To fully support the concept of scheduling partitions in the default
hierarchy, we need to add some new field into the cpuset structure as
well as a new tmpmasks structure that is used to pre-allocate cpumasks
at the top level cpuset functions to avoid memory allocation in inner
functions as memory allocation failure in those inner functions may
cause a cpuset to have inconsistent states.

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08 12:27:27 -08:00
Waiman Long
4ec22e9c5a cpuset: Enable cpuset controller in default hierarchy
Given the fact that thread mode had been merged into 4.14, it is now
time to enable cpuset to be used in the default hierarchy (cgroup v2)
as it is clearly threaded.

The cpuset controller had experienced feature creep since its
introduction more than a decade ago. Besides the core cpus and mems
control files to limit cpus and memory nodes, there are a bunch of
additional features that can be controlled from the userspace. Some of
the features are of doubtful usefulness and may not be actively used.

This patch enables cpuset controller in the default hierarchy with
a minimal set of features, namely just the cpus and mems and their
effective_* counterparts.  We can certainly add more features to the
default hierarchy in the future if there is a real user need for them
later on.

Alternatively, with the unified hiearachy, it may make more sense
to move some of those additional cpuset features, if desired, to
memory controller or may be to the cpu controller instead of staying
with cpuset.

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-11-08 12:27:27 -08:00
Mauro Carvalho Chehab
5fb94e9ca3 docs: Fix some broken references
As we move stuff around, some doc references are broken. Fix some of
them via this script:
	./scripts/documentation-file-ref-check --fix

Manually checked if the produced result is valid, removing a few
false-positives.

Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
2018-06-15 18:10:01 -03:00
Kees Cook
6da2ec5605 treewide: kmalloc() -> kmalloc_array()
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

        kmalloc(a * b, gfp)

with:
        kmalloc_array(a * b, gfp)

as well as handling cases of:

        kmalloc(a * b * c, gfp)

with:

        kmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kmalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kmalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kmalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kmalloc
+ kmalloc_array
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kmalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kmalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kmalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kmalloc(sizeof(THING) * C2, ...)
|
  kmalloc(sizeof(TYPE) * C2, ...)
|
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Yaowei Bai
77ef80c65a kernel/cpuset: current_cpuset_is_being_rebound can be boolean
Make current_cpuset_is_being_rebound return bool due to this particular
function only using either one or zero as its return value.

No functional change.

Link: http://lkml.kernel.org/r/1513266622-15860-4-git-send-email-baiyaowei@cmss.chinamobile.com
Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:47 -08:00
Frederic Weisbecker
edb9382175 sched/isolation: Move isolcpus= handling to the housekeeping code
We want to centralize the isolation features, to be done by the housekeeping
subsystem and scheduler domain isolation is a significant part of it.

No intended behaviour change, we just reuse the housekeeping cpumask
and core code.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1509072159-31808-11-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-27 09:55:30 +02:00
Linus Torvalds
040b9d7ccf Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Three fixes:

   - fix a suspend/resume cpusets bug

   - fix a !CONFIG_NUMA_BALANCING bug

   - fix a kerneldoc warning"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix nuisance kernel-doc warning
  sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs
  sched/fair: Fix wake_affine_llc() balancing rules
2017-09-12 11:30:56 -07:00
Peter Zijlstra
50e7663233 sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs
Cpusets vs. suspend-resume is _completely_ broken. And it got noticed
because it now resulted in non-cpuset usage breaking too.

On suspend cpuset_cpu_inactive() doesn't call into
cpuset_update_active_cpus() because it doesn't want to move tasks about,
there is no need, all tasks are frozen and won't run again until after
we've resumed everything.

But this means that when we finally do call into
cpuset_update_active_cpus() after resuming the last frozen cpu in
cpuset_cpu_active(), the top_cpuset will not have any difference with
the cpu_active_mask and this it will not in fact do _anything_.

So the cpuset configuration will not be restored. This was largely
hidden because we would unconditionally create identity domains and
mobile users would not in fact use cpusets much. And servers what do use
cpusets tend to not suspend-resume much.

An addition problem is that we'd not in fact wait for the cpuset work to
finish before resuming the tasks, allowing spurious migrations outside
of the specified domains.

Fix the rebuild by introducing cpuset_force_rebuild() and fix the
ordering with cpuset_wait_for_hotplug().

Reported-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: deb7aa308e ("cpuset: reorganize CPU / memory hotplug handling")
Link: http://lkml.kernel.org/r/20170907091338.orwxrqkbfkki3c24@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-07 11:45:21 +02:00
Linus Torvalds
608c1d3c17 Merge branch 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "Several notable changes this cycle:

   - Thread mode was merged. This will be used for cgroup2 support for
     CPU and possibly other controllers. Unfortunately, CPU controller
     cgroup2 support didn't make this pull request but most contentions
     have been resolved and the support is likely to be merged before
     the next merge window.

   - cgroup.stat now shows the number of descendant cgroups.

   - cpuset now can enable the easier-to-configure v2 behavior on v1
     hierarchy"

* 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits)
  cpuset: Allow v2 behavior in v1 cgroup
  cgroup: Add mount flag to enable cpuset to use v2 behavior in v1 cgroup
  cgroup: remove unneeded checks
  cgroup: misc changes
  cgroup: short-circuit cset_cgroup_from_root() on the default hierarchy
  cgroup: re-use the parent pointer in cgroup_destroy_locked()
  cgroup: add cgroup.stat interface with basic hierarchy stats
  cgroup: implement hierarchy limits
  cgroup: keep track of number of descent cgroups
  cgroup: add comment to cgroup_enable_threaded()
  cgroup: remove unnecessary empty check when enabling threaded mode
  cgroup: update debug controller to print out thread mode information
  cgroup: implement cgroup v2 thread support
  cgroup: implement CSS_TASK_ITER_THREADED
  cgroup: introduce cgroup->dom_cgrp and threaded css_set handling
  cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS
  cgroup: reorganize cgroup.procs / task write path
  cgroup: replace css_set walking populated test with testing cgrp->nr_populated_csets
  cgroup: distinguish local and children populated states
  cgroup: remove now unused list_head @pending in cgroup_apply_cftypes()
  ...
2017-09-06 22:25:25 -07:00
Michal Hocko
da99ecf117 mm: replace TIF_MEMDIE checks by tsk_is_oom_victim
TIF_MEMDIE is set only to the tasks whick were either directly selected
by the OOM killer or passed through mark_oom_victim from the allocator
path.  tsk_is_oom_victim is more generic and allows to identify all
tasks (threads) which share the mm with the oom victim.

Please note that the freezer still needs to check TIF_MEMDIE because we
cannot thaw tasks which do not participage in oom_victims counting
otherwise a !TIF_MEMDIE task could interfere after oom_disbale returns.

Link: http://lkml.kernel.org/r/20170810075019.28998-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06 17:27:30 -07:00
Linus Torvalds
5f82e71a00 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:

 - Add 'cross-release' support to lockdep, which allows APIs like
   completions, where it's not the 'owner' who releases the lock, to be
   tracked. It's all activated automatically under
   CONFIG_PROVE_LOCKING=y.

 - Clean up (restructure) the x86 atomics op implementation to be more
   readable, in preparation of KASAN annotations. (Dmitry Vyukov)

 - Fix static keys (Paolo Bonzini)

 - Add killable versions of down_read() et al (Kirill Tkhai)

 - Rework and fix jump_label locking (Marc Zyngier, Paolo Bonzini)

 - Rework (and fix) tlb_flush_pending() barriers (Peter Zijlstra)

 - Remove smp_mb__before_spinlock() and convert its usages, introduce
   smp_mb__after_spinlock() (Peter Zijlstra)

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (56 commits)
  locking/lockdep/selftests: Fix mixed read-write ABBA tests
  sched/completion: Avoid unnecessary stack allocation for COMPLETION_INITIALIZER_ONSTACK()
  acpi/nfit: Fix COMPLETION_INITIALIZER_ONSTACK() abuse
  locking/pvqspinlock: Relax cmpxchg's to improve performance on some architectures
  smp: Avoid using two cache lines for struct call_single_data
  locking/lockdep: Untangle xhlock history save/restore from task independence
  locking/refcounts, x86/asm: Disable CONFIG_ARCH_HAS_REFCOUNT for the time being
  futex: Remove duplicated code and fix undefined behaviour
  Documentation/locking/atomic: Finish the document...
  locking/lockdep: Fix workqueue crossrelease annotation
  workqueue/lockdep: 'Fix' flush_work() annotation
  locking/lockdep/selftests: Add mixed read-write ABBA tests
  mm, locking/barriers: Clarify tlb_flush_pending() barriers
  locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE and CONFIG_LOCKDEP_COMPLETIONS truly non-interactive
  locking/lockdep: Explicitly initialize wq_barrier::done::map
  locking/lockdep: Rename CONFIG_LOCKDEP_COMPLETE to CONFIG_LOCKDEP_COMPLETIONS
  locking/lockdep: Reword title of LOCKDEP_CROSSRELEASE config
  locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE part of CONFIG_PROVE_LOCKING
  locking/refcounts, x86/asm: Implement fast refcount overflow protection
  locking/lockdep: Fix the rollback and overwrite detection logic in crossrelease
  ...
2017-09-04 11:52:29 -07:00
Linus Torvalds
f213a6c84c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "The main changes in this cycle were:

   - fix affine wakeups (Peter Zijlstra)

   - improve CPU onlining (and general bootup) scalability on systems
     with ridiculous number (thousands) of CPUs (Peter Zijlstra)

   - sched/numa updates (Rik van Riel)

   - sched/deadline updates (Byungchul Park)

   - sched/cpufreq enhancements and related cleanups (Viresh Kumar)

   - sched/debug enhancements (Xie XiuQi)

   - various fixes"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
  sched/debug: Optimize sched_domain sysctl generation
  sched/topology: Avoid pointless rebuild
  sched/topology, cpuset: Avoid spurious/wrong domain rebuilds
  sched/topology: Improve comments
  sched/topology: Fix memory leak in __sdt_alloc()
  sched/completion: Document that reinit_completion() must be called after complete_all()
  sched/autogroup: Fix error reporting printk text in autogroup_create()
  sched/fair: Fix wake_affine() for !NUMA_BALANCING
  sched/debug: Intruduce task_state_to_char() helper function
  sched/debug: Show task state in /proc/sched_debug
  sched/debug: Use task_pid_nr_ns in /proc/$pid/sched
  sched/core: Remove unnecessary initialization init_idle_bootup_task()
  sched/deadline: Change return value of cpudl_find()
  sched/deadline: Make find_later_rq() choose a closer CPU in topology
  sched/numa: Scale scan period with tasks in group and shared/private
  sched/numa: Slow down scan rate if shared faults dominate
  sched/pelt: Fix false running accounting
  sched: Mark pick_next_task_dl() and build_sched_domain() as static
  sched/cpupri: Don't re-initialize 'struct cpupri'
  sched/deadline: Don't re-initialize 'struct cpudl'
  ...
2017-09-04 09:10:24 -07:00
Ingo Molnar
edc2988c54 Merge branch 'linus' into locking/core, to fix up conflicts
Conflicts:
	mm/page_alloc.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-04 11:01:18 +02:00
Linus Torvalds
36fde05f3f Merge branch 'for-4.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fix from Tejun Heo:
 "A late but obvious fix for cgroup.

  I broke the 'cpuset.memory_pressure' file a long time ago (v4.4) by
  accidentally deleting its file index, which made it a duplicate of the
  'cpuset.memory_migrate' file. Spotted and fixed by Waiman"

* 'for-4.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cpuset: Fix incorrect memory_pressure control file mapping
2017-08-29 11:16:21 -07:00