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620a6dc407
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Valentin Schneider 620a6dc407 sched/topology: Make sched_init_numa() use a set for the deduplicating sort 
The deduplicating sort in sched_init_numa() assumes that the first line in
the distance table contains all unique values in the entire table. I've
been trying to pen what this exactly means for the topology, but it's not
straightforward. For instance, topology.c uses this example:

  node   0   1   2   3
    0:  10  20  20  30
    1:  20  10  20  20
    2:  20  20  10  20
    3:  30  20  20  10

  0 ----- 1
  |     / |
  |   /   |
  | /     |
  2 ----- 3

Which works out just fine. However, if we swap nodes 0 and 1:

  1 ----- 0
  |     / |
  |   /   |
  | /     |
  2 ----- 3

we get this distance table:

  node   0  1  2  3
    0:  10 20 20 20
    1:  20 10 20 30
    2:  20 20 10 20
    3:  20 30 20 10

Which breaks the deduplicating sort (non-representative first line). In
this case this would just be a renumbering exercise, but it so happens that
we can have a deduplicating sort that goes through the whole table in O(n²)
at the extra cost of a temporary memory allocation (i.e. any form of set).

The ACPI spec (SLIT) mentions distances are encoded on 8 bits. Following
this, implement the set as a 256-bits bitmap. Should this not be
satisfactory (i.e. we want to support 32-bit values), then we'll have to go
for some other sparse set implementation.

This has the added benefit of letting us allocate just the right amount of
memory for sched_domains_numa_distance[], rather than an arbitrary
(nr_node_ids + 1).

Note: DT binding equivalent (distance-map) decodes distances as 32-bit
values.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210122123943.1217-2-valentin.schneider@arm.com
2021-01-27 17:26:42 +01:00
..
bpf Merge branch 'exec-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-12-15 19:29:43 -08:00
cgroup Merge branch 'for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2020-12-28 11:16:38 -08:00
configs Input: gtco - remove driver 2020-12-09 17:47:36 -08:00
debug smp: Cleanup smp_call_function*() 2020-11-24 16:47:49 +01:00
dma dma-mapping updates for 5.11: 2020-12-22 13:19:43 -08:00
entry The new preemtible kmap_local() implementation: 2020-12-14 18:35:53 -08:00
events Merge branch 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-12-15 19:36:48 -08:00
gcov gcov: fix kernel-doc markup issue 2020-12-15 22:46:18 -08:00
irq genirq: Fix export of irq_to_desc() for powerpc KVM 2020-12-25 11:02:39 -08:00
kcsan kcsan: Fix encoding masks and regain address bit 2020-11-06 17:19:26 -08:00
livepatch livepatch: Use the default ftrace_ops instead of REGS when ARGS is available 2020-11-13 12:15:28 -05:00
locking A moderate set of locking updates: 2020-12-14 17:27:47 -08:00
power Power management updates for 5.11-rc1 2020-12-15 16:30:31 -08:00
printk printk changes for 5.11 2020-12-16 10:45:11 -08:00
rcu Scheduler updates: 2020-12-14 18:29:11 -08:00
sched sched/topology: Make sched_init_numa() use a set for the deduplicating sort 2021-01-27 17:26:42 +01:00
time Update/fix two CPU sanity checks in the hotplug and the boot code, 2020-12-27 09:03:41 -08:00
trace Tracing updates for 5.11 2020-12-17 13:22:17 -08:00
.gitignore
acct.c kernel/acct.c: use #elif instead of #end and #elif 2020-12-15 22:46:15 -08:00
async.c treewide: Remove uninitialized_var() usage 2020-07-16 12:35:15 -07:00
audit_fsnotify.c fsnotify: generalize handle_inode_event() 2020-12-03 14:58:35 +01:00
audit_tree.c fsnotify: generalize handle_inode_event() 2020-12-03 14:58:35 +01:00
audit_watch.c fsnotify: generalize handle_inode_event() 2020-12-03 14:58:35 +01:00
audit.c audit: replace atomic_add_return() 2020-12-02 22:52:16 -05:00
audit.h audit: change unnecessary globals into statics 2020-08-17 20:26:58 -04:00
auditfilter.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
auditsc.c audit/stable-5.11 PR 20201214 2020-12-16 10:54:03 -08:00
backtracetest.c treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD() 2020-07-30 11:15:58 -07:00
bounds.c
capability.c LSM: Signal to SafeSetID when setting group IDs 2020-10-13 09:17:34 -07:00
compat.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
configs.c
context_tracking.c
cpu_pm.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
cpu.c Scheduler updates: 2020-12-14 18:29:11 -08:00
crash_core.c kdump: append uts_namespace.name offset to VMCOREINFO 2020-12-15 22:46:18 -08:00
crash_dump.c
cred.c
delayacct.c
dma.c
exec_domain.c
exit.c kernel/io_uring: cancel io_uring before task works 2020-12-30 19:36:54 -07:00
extable.c
fail_function.c fault-injection: handle EI_ETYPE_TRUE 2020-12-15 22:46:19 -08:00
fork.c kasan: rename (un)poison_shadow to (un)poison_range 2020-12-22 12:55:06 -08:00
freezer.c
futex.c Merge branch 'locking/rwsem' 2020-12-09 17:08:45 +01:00
gen_kheaders.sh
groups.c LSM: Signal to SafeSetID when setting group IDs 2020-10-13 09:17:34 -07:00
hung_task.c kernel/hung_task.c: make type annotations consistent 2020-11-02 12:14:19 -08:00
iomem.c
irq_work.c irq_work: Optimize irq_work_single() 2020-11-24 16:47:49 +01:00
jump_label.c jump_label: Fix usage in module __init 2020-12-18 16:53:12 +01:00
kallsyms.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
kcmp.c Merge branch 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-12-15 19:36:48 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kernel: make kcov_common_handle consider the current context 2020-11-02 18:00:20 -08:00
kexec_core.c crypto: sha - split sha.h into sha1.h and sha2.h 2020-11-20 14:45:33 +11:00
kexec_elf.c
kexec_file.c crypto: sha - split sha.h into sha1.h and sha2.h 2020-11-20 14:45:33 +11:00
kexec_internal.h
kexec.c LSM: Introduce kernel_post_load_data() hook 2020-10-05 13:37:03 +02:00
kheaders.c
kmod.c kmod: remove redundant "be an" in the comment 2020-08-12 10:58:01 -07:00
kprobes.c Merge branch 'linus' into perf/kprobes 2020-11-07 13:18:49 +01:00
ksysfs.c
kthread.c Merge branch 'akpm' (patches from Andrew) 2020-12-15 12:53:37 -08:00
latencytop.c
Makefile kcov: don't instrument with UBSAN 2020-12-15 22:46:19 -08:00
module_signature.c
module_signing.c
module-internal.h
module.c Modules updates for v5.11 2020-12-17 13:01:31 -08:00
notifier.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
nsproxy.c fixes-v5.11 2020-12-14 16:40:27 -08:00
padata.c padata: fix possible padata_works_lock deadlock 2020-09-04 17:51:55 +10:00
panic.c panic: don't dump stack twice on warn 2020-11-14 11:26:04 -08:00
params.c Modules updates for v5.11 2020-12-17 13:01:31 -08:00
pid_namespace.c fixes-v5.11 2020-12-14 16:40:27 -08:00
pid.c Merge branch 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-12-15 19:36:48 -08:00
profile.c
ptrace.c Merge branch 'akpm' (patches from Andrew) 2020-12-15 12:53:37 -08:00
range.c kernel.h: split out min()/max() et al. helpers 2020-10-16 11:11:19 -07:00
reboot.c reboot: hide from sysfs not applicable settings 2020-12-15 22:46:19 -08:00
regset.c regset: kill ->get() 2020-07-27 14:31:12 -04:00
relay.c relay: allow the use of const callback structs 2020-12-15 22:46:18 -08:00
resource_kunit.c resource: provide meaningful MODULE_LICENSE() in test suite 2020-11-25 18:52:35 +01:00
resource.c kernel/resource.c: fix kernel-doc markups 2020-12-15 22:46:18 -08:00
rseq.c
scftorture.c scftorture: Add full-test stutter capability 2020-11-06 17:13:56 -08:00
scs.c scs: switch to vmapped shadow stacks 2020-12-01 10:30:28 +00:00
seccomp.c seccomp updates for v5.11-rc1 2020-12-16 11:30:10 -08:00
signal.c tif-task_work.arch-2020-12-14 2020-12-16 12:33:35 -08:00
smp.c Merge branch 'linus' into sched/core, to resolve semantic conflict 2020-11-27 11:10:50 +01:00
smpboot.c
smpboot.h
softirq.c Misc fixes/updates: 2020-12-27 09:06:10 -08:00
stackleak.c stackleak: let stack_erasing_sysctl take a kernel pointer buffer 2020-09-19 13:13:39 -07:00
stacktrace.c stacktrace: Remove reliable argument from arch_stack_walk() callback 2020-09-18 14:24:16 +01:00
static_call.c static_call: Fix return type of static_call_init 2020-10-02 21:18:25 +02:00
stop_machine.c Merge branch 'linus' into sched/core, to resolve semantic conflict 2020-11-27 11:10:50 +01:00
sys_ni.c epoll: wire up syscall epoll_pwait2 2020-12-19 11:18:38 -08:00
sys.c kernel: Implement selective syscall userspace redirection 2020-12-02 15:07:56 +01:00
sysctl-test.c
sysctl.c rcu: Panic after fixed number of stalls 2020-11-19 19:37:16 -08:00
task_work.c task_work: remove legacy TWA_SIGNAL path 2020-12-12 09:17:38 -07:00
taskstats.c treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
test_kprobes.c
torture.c rcutorture: Make stutter_wait() caller restore priority 2020-11-06 17:13:54 -08:00
tracepoint.c tracepoints: Migrate to use SYSCALL_WORK flag 2020-11-16 21:53:15 +01:00
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c usermodehelper: reset umask to default before executing user process 2020-10-06 10:31:52 -07:00
up.c
user_namespace.c fixes-v5.11 2020-12-14 16:40:27 -08:00
user-return-notifier.c
user.c user: Use generic ns_common::count 2020-08-19 14:14:12 +02:00
usermode_driver.c
utsname_sysctl.c
utsname.c uts: Use generic ns_common::count 2020-08-19 14:13:20 +02:00
watch_queue.c watch_queue: Limit the number of watches a user can hold 2020-08-17 09:39:18 -07:00
watchdog_hld.c
watchdog.c kernel/watchdog: fix watchdog_allowed_mask not used warning 2020-11-14 11:26:03 -08:00
workqueue_internal.h
workqueue.c Merge branch 'for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2020-12-28 11:23:02 -08:00