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1448 commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Zhen Lei
|
bc1cca97e6 |
sched/debug: Show the registers of 'current' in dump_cpu_task()
The dump_cpu_task() function does not print registers on architectures that do not support NMIs. However, registers can be useful for debugging. Fortunately, in the case where dump_cpu_task() is invoked from an interrupt handler and is dumping the current CPU's stack, the get_irq_regs() function can be used to get the registers. Therefore, this commit makes dump_cpu_task() check to see if it is being asked to dump the current CPU's stack from within an interrupt handler, and, if so, it uses the get_irq_regs() function to obtain the registers. On systems that do support NMIs, this commit has the further advantage of avoiding a self-NMI in this case. This is an example of rcu self-detected stall on arm64, which does not support NMIs: [ 27.501721] rcu: INFO: rcu_preempt self-detected stall on CPU [ 27.502238] rcu: 0-....: (1250 ticks this GP) idle=4f7/1/0x4000000000000000 softirq=2594/2594 fqs=619 [ 27.502632] (t=1251 jiffies g=2989 q=29 ncpus=4) [ 27.503845] CPU: 0 PID: 306 Comm: test0 Not tainted 5.19.0-rc7-00009-g1c1a6c29ff99-dirty #46 [ 27.504732] Hardware name: linux,dummy-virt (DT) [ 27.504947] pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 27.504998] pc : arch_counter_read+0x18/0x24 [ 27.505301] lr : arch_counter_read+0x18/0x24 [ 27.505328] sp : ffff80000b29bdf0 [ 27.505345] x29: ffff80000b29bdf0 x28: 0000000000000000 x27: 0000000000000000 [ 27.505475] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 [ 27.505553] x23: 0000000000001f40 x22: ffff800009849c48 x21: 000000065f871ae0 [ 27.505627] x20: 00000000000025ec x19: ffff80000a6eb300 x18: ffffffffffffffff [ 27.505654] x17: 0000000000000001 x16: 0000000000000000 x15: ffff80000a6d0296 [ 27.505681] x14: ffffffffffffffff x13: ffff80000a29bc18 x12: 0000000000000426 [ 27.505709] x11: 0000000000000162 x10: ffff80000a2f3c18 x9 : ffff80000a29bc18 [ 27.505736] x8 : 00000000ffffefff x7 : ffff80000a2f3c18 x6 : 00000000759bd013 [ 27.505761] x5 : 01ffffffffffffff x4 : 0002dc6c00000000 x3 : 0000000000000017 [ 27.505787] x2 : 00000000000025ec x1 : ffff80000b29bdf0 x0 : 0000000075a30653 [ 27.505937] Call trace: [ 27.506002] arch_counter_read+0x18/0x24 [ 27.506171] ktime_get+0x48/0xa0 [ 27.506207] test_task+0x70/0xf0 [ 27.506227] kthread+0x10c/0x110 [ 27.506243] ret_from_fork+0x10/0x20 This is a marked improvement over the old output: [ 27.944550] rcu: INFO: rcu_preempt self-detected stall on CPU [ 27.944980] rcu: 0-....: (1249 ticks this GP) idle=cbb/1/0x4000000000000000 softirq=2610/2610 fqs=614 [ 27.945407] (t=1251 jiffies g=2681 q=28 ncpus=4) [ 27.945731] Task dump for CPU 0: [ 27.945844] task:test0 state:R running task stack: 0 pid: 306 ppid: 2 flags:0x0000000a [ 27.946073] Call trace: [ 27.946151] dump_backtrace.part.0+0xc8/0xd4 [ 27.946378] show_stack+0x18/0x70 [ 27.946405] sched_show_task+0x150/0x180 [ 27.946427] dump_cpu_task+0x44/0x54 [ 27.947193] rcu_dump_cpu_stacks+0xec/0x130 [ 27.947212] rcu_sched_clock_irq+0xb18/0xef0 [ 27.947231] update_process_times+0x68/0xac [ 27.947248] tick_sched_handle+0x34/0x60 [ 27.947266] tick_sched_timer+0x4c/0xa4 [ 27.947281] __hrtimer_run_queues+0x178/0x360 [ 27.947295] hrtimer_interrupt+0xe8/0x244 [ 27.947309] arch_timer_handler_virt+0x38/0x4c [ 27.947326] handle_percpu_devid_irq+0x88/0x230 [ 27.947342] generic_handle_domain_irq+0x2c/0x44 [ 27.947357] gic_handle_irq+0x44/0xc4 [ 27.947376] call_on_irq_stack+0x2c/0x54 [ 27.947415] do_interrupt_handler+0x80/0x94 [ 27.947431] el1_interrupt+0x34/0x70 [ 27.947447] el1h_64_irq_handler+0x18/0x24 [ 27.947462] el1h_64_irq+0x64/0x68 <--- the above backtrace is worthless [ 27.947474] arch_counter_read+0x18/0x24 [ 27.947487] ktime_get+0x48/0xa0 [ 27.947501] test_task+0x70/0xf0 [ 27.947520] kthread+0x10c/0x110 [ 27.947538] ret_from_fork+0x10/0x20 Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> |
||
|
Zhen Lei
|
e73dfe3093 |
sched/debug: Try trigger_single_cpu_backtrace(cpu) in dump_cpu_task()
The trigger_all_cpu_backtrace() function attempts to send an NMI to the target CPU, which usually provides much better stack traces than the dump_cpu_task() function's approach of dumping that stack from some other CPU. So much so that most calls to dump_cpu_task() only happen after a call to trigger_all_cpu_backtrace() has failed. And the exception to this rule really should attempt to use trigger_all_cpu_backtrace() first. Therefore, move the trigger_all_cpu_backtrace() invocation into dump_cpu_task(). Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> |
||
|
Linus Torvalds
|
cac03ac368 |
Various fixes: a deadline scheduler fix, a migration fix, a Sparse fix and a comment fix.
Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmLuvmwRHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1gONQ/+KkkPTeKgGDvrahTfeYZlmRyvcI1R78r9 yooa8v+DtifznBW2eXDBc8WTruzqr78VyUY+1YSjfKS6FRQWYMficJ3qk3hxgBru 998KZbvl3jXBBlRkqgGeFlF5Ty2KaryEZgX97a7IF/0xWDgpm972jFkJ/KCo/YTY WSQrzutz2FKe71EjK4cAplYxPZIiy/zo2hSGTbsso4M7bO5VLc1Y4qMtFGcCZ7JB s9JYkj2Rfz+AS5wioDRcGuec4A4SrroxKszZA6QDDBuhMJukqexO02xs/fxZ2W4Z DF4U5MFOrtz9AWSGsf1P6XXbgJO8qTgQXZchFsEcJwypV13w8U0IViXQfD/Pvx2X y+WHdnZVIO2sDwOJ15ew7IuoJZ2LsVygrBNFJJaIFOtIz3RzprI0BJN7LeWFALOa IPmbtiY8hVwhKmjRgMHWDwJhMEHLuhGx3idiD89w1pknzTUnKDiwLyEUtyynxeGd ft9uCvPefrYQVx9AiH7wf0W+fg334FCccC+0f8LyduyftUyQCfZIZY6LUSKuKded Odm7k0ngLDPbdZwAHs0Nf/ilRwd91Z7b6hGt5U3ptx+8BPMKB+/k1VoKog7OISPc zGaP7DrtuC4sEdX4X6bqX+mEQhpkLcQw15gVGxhKoHqygWNSZrV634aSSXwfVXJx eT5m/K9a7L0= =CYl5 -----END PGP SIGNATURE----- Merge tag 'sched-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Various fixes: a deadline scheduler fix, a migration fix, a Sparse fix and a comment fix" * tag 'sched-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Do not requeue task on CPU excluded from cpus_mask sched/rt: Fix Sparse warnings due to undefined rt.c declarations exit: Fix typo in comment: s/sub-theads/sub-threads sched, cpuset: Fix dl_cpu_busy() panic due to empty cs->cpus_allowed |
||
|
Mel Gorman
|
751d4cbc43 |
sched/core: Do not requeue task on CPU excluded from cpus_mask
The following warning was triggered on a large machine early in boot on
a distribution kernel but the same problem should also affect mainline.
WARNING: CPU: 439 PID: 10 at ../kernel/workqueue.c:2231 process_one_work+0x4d/0x440
Call Trace:
<TASK>
rescuer_thread+0x1f6/0x360
kthread+0x156/0x180
ret_from_fork+0x22/0x30
</TASK>
Commit
|
||
|
Waiman Long
|
b6e8d40d43 |
sched, cpuset: Fix dl_cpu_busy() panic due to empty cs->cpus_allowed
With cgroup v2, the cpuset's cpus_allowed mask can be empty indicating
that the cpuset will just use the effective CPUs of its parent. So
cpuset_can_attach() can call task_can_attach() with an empty mask.
This can lead to cpumask_any_and() returns nr_cpu_ids causing the call
to dl_bw_of() to crash due to percpu value access of an out of bound
CPU value. For example:
[80468.182258] BUG: unable to handle page fault for address: ffffffff8b6648b0
:
[80468.191019] RIP: 0010:dl_cpu_busy+0x30/0x2b0
:
[80468.207946] Call Trace:
[80468.208947] cpuset_can_attach+0xa0/0x140
[80468.209953] cgroup_migrate_execute+0x8c/0x490
[80468.210931] cgroup_update_dfl_csses+0x254/0x270
[80468.211898] cgroup_subtree_control_write+0x322/0x400
[80468.212854] kernfs_fop_write_iter+0x11c/0x1b0
[80468.213777] new_sync_write+0x11f/0x1b0
[80468.214689] vfs_write+0x1eb/0x280
[80468.215592] ksys_write+0x5f/0xe0
[80468.216463] do_syscall_64+0x5c/0x80
[80468.224287] entry_SYSCALL_64_after_hwframe+0x44/0xae
Fix that by using effective_cpus instead. For cgroup v1, effective_cpus
is the same as cpus_allowed. For v2, effective_cpus is the real cpumask
to be used by tasks within the cpuset anyway.
Also update task_can_attach()'s 2nd argument name to cs_effective_cpus to
reflect the change. In addition, a check is added to task_can_attach()
to guard against the possibility that cpumask_any_and() may return a
value >= nr_cpu_ids.
Fixes:
|
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Linus Torvalds
|
7d9d077c78 |
RCU pull request for v5.20 (or whatever)
This pull request contains the following branches: doc.2022.06.21a: Documentation updates. fixes.2022.07.19a: Miscellaneous fixes. nocb.2022.07.19a: Callback-offload updates, perhaps most notably a new RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to be offloaded at boot time, regardless of kernel boot parameters. This is useful to battery-powered systems such as ChromeOS and Android. In addition, a new RCU_NOCB_CPU_CB_BOOST kernel boot parameter prevents offloaded callbacks from interfering with real-time workloads and with energy-efficiency mechanisms. poll.2022.07.21a: Polled grace-period updates, perhaps most notably making these APIs account for both normal and expedited grace periods. rcu-tasks.2022.06.21a: Tasks RCU updates, perhaps most notably reducing the CPU overhead of RCU tasks trace grace periods by more than a factor of two on a system with 15,000 tasks. The reduction is expected to increase with the number of tasks, so it seems reasonable to hypothesize that a system with 150,000 tasks might see a 20-fold reduction in CPU overhead. torture.2022.06.21a: Torture-test updates. ctxt.2022.07.05a: Updates that merge RCU's dyntick-idle tracking into context tracking, thus reducing the overhead of transitioning to kernel mode from either idle or nohz_full userspace execution for kernels that track context independently of RCU. This is expected to be helpful primarily for kernels built with CONFIG_NO_HZ_FULL=y. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEbK7UrM+RBIrCoViJnr8S83LZ+4wFAmLgMcgTHHBhdWxtY2tA a2VybmVsLm9yZwAKCRCevxLzctn7jArXD/0fjbCwqpRjHVTzjMY8jN4zDkqZZD6m g8Fx27hZ4ToNFwRptyHwNezrNj14skjAJEXfdjaVw32W62ivXvf0HINvSzsTLCSq k2kWyBdXLc9CwY5p5W4smnpn5VoAScjg5PoPL59INoZ/Zziji323C7Zepl/1DYJt 0T6bPCQjo1ZQoDUCyVpSjDmAqxnderWG0MeJVt74GkLqmnYLANg0GH8c7mH4+9LL kVGlLp5nlPgNJ4FEoFdMwNU8T/ETmaVld/m2dkiawjkXjJzB2XKtBigU91DDmXz5 7DIdV4ABrxiy4kGNqtIe/jFgnKyVD7xiDpyfjd6KTeDr/rDS8u2ZH7+1iHsyz3g0 Np/tS3vcd0KR+gI/d0eXxPbgm5sKlCmKw/nU2eArpW/+4LmVXBUfHTG9Jg+LJmBc JrUh6aEdIZJZHgv/nOQBNig7GJW43IG50rjuJxAuzcxiZNEG5lUSS23ysaA9CPCL PxRWKSxIEfK3kdmvVO5IIbKTQmIBGWlcWMTcYictFSVfBgcCXpPAksGvqA5JiUkc egW+xLFo/7K+E158vSKsVqlWZcEeUbsNJ88QOlpqnRgH++I2Yv/LhK41XfJfpH+Y ALxVaDd+mAq6v+qSHNVq9wT3ozXIPy/zK1hDlMIqx40h2YvaEsH4je+521oSoN9r vX60+QNxvUBLwA== =vUNm -----END PGP SIGNATURE----- Merge tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull RCU updates from Paul McKenney: - Documentation updates - Miscellaneous fixes - Callback-offload updates, perhaps most notably a new RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to be offloaded at boot time, regardless of kernel boot parameters. This is useful to battery-powered systems such as ChromeOS and Android. In addition, a new RCU_NOCB_CPU_CB_BOOST kernel boot parameter prevents offloaded callbacks from interfering with real-time workloads and with energy-efficiency mechanisms - Polled grace-period updates, perhaps most notably making these APIs account for both normal and expedited grace periods - Tasks RCU updates, perhaps most notably reducing the CPU overhead of RCU tasks trace grace periods by more than a factor of two on a system with 15,000 tasks. The reduction is expected to increase with the number of tasks, so it seems reasonable to hypothesize that a system with 150,000 tasks might see a 20-fold reduction in CPU overhead - Torture-test updates - Updates that merge RCU's dyntick-idle tracking into context tracking, thus reducing the overhead of transitioning to kernel mode from either idle or nohz_full userspace execution for kernels that track context independently of RCU. This is expected to be helpful primarily for kernels built with CONFIG_NO_HZ_FULL=y * tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (98 commits) rcu: Add irqs-disabled indicator to expedited RCU CPU stall warnings rcu: Diagnose extended sync_rcu_do_polled_gp() loops rcu: Put panic_on_rcu_stall() after expedited RCU CPU stall warnings rcutorture: Test polled expedited grace-period primitives rcu: Add polled expedited grace-period primitives rcutorture: Verify that polled GP API sees synchronous grace periods rcu: Make Tiny RCU grace periods visible to polled APIs rcu: Make polled grace-period API account for expedited grace periods rcu: Switch polled grace-period APIs to ->gp_seq_polled rcu/nocb: Avoid polling when my_rdp->nocb_head_rdp list is empty rcu/nocb: Add option to opt rcuo kthreads out of RT priority rcu: Add nocb_cb_kthread check to rcu_is_callbacks_kthread() rcu/nocb: Add an option to offload all CPUs on boot rcu/nocb: Fix NOCB kthreads spawn failure with rcu_nocb_rdp_deoffload() direct call rcu/nocb: Invert rcu_state.barrier_mutex VS hotplug lock locking order rcu/nocb: Add/del rdp to iterate from rcuog itself rcu/tree: Add comment to describe GP-done condition in fqs loop rcu: Initialize first_gp_fqs at declaration in rcu_gp_fqs() rcu/kvfree: Remove useless monitor_todo flag rcu: Cleanup RCU urgency state for offline CPU ... |
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Linus Torvalds
|
b349b1181d |
for-5.20/io_uring-2022-07-29
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|
Linus Torvalds
|
b167fdffe9 |
This cycle's scheduler updates for v6.0 are:
Load-balancing improvements:
============================
- Improve NUMA balancing on AMD Zen systems for affine workloads.
- Improve the handling of reduced-capacity CPUs in load-balancing.
- Energy Model improvements: fix & refine all the energy fairness metrics (PELT),
and remove the conservative threshold requiring 6% energy savings to
migrate a task. Doing this improves power efficiency for most workloads,
and also increases the reliability of energy-efficiency scheduling.
- Optimize/tweak select_idle_cpu() to spend (much) less time searching
for an idle CPU on overloaded systems. There's reports of several
milliseconds spent there on large systems with large workloads ...
[ Since the search logic changed, there might be behavioral side effects. ]
- Improve NUMA imbalance behavior. On certain systems
with spare capacity, initial placement of tasks is non-deterministic,
and such an artificial placement imbalance can persist for a long time,
hurting (and sometimes helping) performance.
The fix is to make fork-time task placement consistent with runtime
NUMA balancing placement.
Note that some performance regressions were reported against this,
caused by workloads that are not memory bandwith limited, which benefit
from the artificial locality of the placement bug(s). Mel Gorman's
conclusion, with which we concur, was that consistency is better than
random workload benefits from non-deterministic bugs:
"Given there is no crystal ball and it's a tradeoff, I think it's
better to be consistent and use similar logic at both fork time
and runtime even if it doesn't have universal benefit."
- Improve core scheduling by fixing a bug in sched_core_update_cookie() that
caused unnecessary forced idling.
- Improve wakeup-balancing by allowing same-LLC wakeup of idle CPUs for newly
woken tasks.
- Fix a newidle balancing bug that introduced unnecessary wakeup latencies.
ABI improvements/fixes:
=======================
- Do not check capabilities and do not issue capability check denial messages
when a scheduler syscall doesn't require privileges. (Such as increasing niceness.)
- Add forced-idle accounting to cgroups too.
- Fix/improve the RSEQ ABI to not just silently accept unknown flags.
(No existing tooling is known to have learned to rely on the previous behavior.)
- Depreciate the (unused) RSEQ_CS_FLAG_NO_RESTART_ON_* flags.
Optimizations:
==============
- Optimize & simplify leaf_cfs_rq_list()
- Micro-optimize set_nr_{and_not,if}_polling() via try_cmpxchg().
Misc fixes & cleanups:
======================
- Fix the RSEQ self-tests on RISC-V and Glibc 2.35 systems.
- Fix a full-NOHZ bug that can in some cases result in the tick not being
re-enabled when the last SCHED_RT task is gone from a runqueue but there's
still SCHED_OTHER tasks around.
- Various PREEMPT_RT related fixes.
- Misc cleanups & smaller fixes.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"Load-balancing improvements:
- Improve NUMA balancing on AMD Zen systems for affine workloads.
- Improve the handling of reduced-capacity CPUs in load-balancing.
- Energy Model improvements: fix & refine all the energy fairness
metrics (PELT), and remove the conservative threshold requiring 6%
energy savings to migrate a task. Doing this improves power
efficiency for most workloads, and also increases the reliability
of energy-efficiency scheduling.
- Optimize/tweak select_idle_cpu() to spend (much) less time
searching for an idle CPU on overloaded systems. There's reports of
several milliseconds spent there on large systems with large
workloads ...
[ Since the search logic changed, there might be behavioral side
effects. ]
- Improve NUMA imbalance behavior. On certain systems with spare
capacity, initial placement of tasks is non-deterministic, and such
an artificial placement imbalance can persist for a long time,
hurting (and sometimes helping) performance.
The fix is to make fork-time task placement consistent with runtime
NUMA balancing placement.
Note that some performance regressions were reported against this,
caused by workloads that are not memory bandwith limited, which
benefit from the artificial locality of the placement bug(s). Mel
Gorman's conclusion, with which we concur, was that consistency is
better than random workload benefits from non-deterministic bugs:
"Given there is no crystal ball and it's a tradeoff, I think
it's better to be consistent and use similar logic at both fork
time and runtime even if it doesn't have universal benefit."
- Improve core scheduling by fixing a bug in
sched_core_update_cookie() that caused unnecessary forced idling.
- Improve wakeup-balancing by allowing same-LLC wakeup of idle CPUs
for newly woken tasks.
- Fix a newidle balancing bug that introduced unnecessary wakeup
latencies.
ABI improvements/fixes:
- Do not check capabilities and do not issue capability check denial
messages when a scheduler syscall doesn't require privileges. (Such
as increasing niceness.)
- Add forced-idle accounting to cgroups too.
- Fix/improve the RSEQ ABI to not just silently accept unknown flags.
(No existing tooling is known to have learned to rely on the
previous behavior.)
- Depreciate the (unused) RSEQ_CS_FLAG_NO_RESTART_ON_* flags.
Optimizations:
- Optimize & simplify leaf_cfs_rq_list()
- Micro-optimize set_nr_{and_not,if}_polling() via try_cmpxchg().
Misc fixes & cleanups:
- Fix the RSEQ self-tests on RISC-V and Glibc 2.35 systems.
- Fix a full-NOHZ bug that can in some cases result in the tick not
being re-enabled when the last SCHED_RT task is gone from a
runqueue but there's still SCHED_OTHER tasks around.
- Various PREEMPT_RT related fixes.
- Misc cleanups & smaller fixes"
* tag 'sched-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
rseq: Kill process when unknown flags are encountered in ABI structures
rseq: Deprecate RSEQ_CS_FLAG_NO_RESTART_ON_* flags
sched/core: Fix the bug that task won't enqueue into core tree when update cookie
nohz/full, sched/rt: Fix missed tick-reenabling bug in dequeue_task_rt()
sched/core: Always flush pending blk_plug
sched/fair: fix case with reduced capacity CPU
sched/core: Use try_cmpxchg in set_nr_{and_not,if}_polling
sched/core: add forced idle accounting for cgroups
sched/fair: Remove the energy margin in feec()
sched/fair: Remove task_util from effective utilization in feec()
sched/fair: Use the same cpumask per-PD throughout find_energy_efficient_cpu()
sched/fair: Rename select_idle_mask to select_rq_mask
sched, drivers: Remove max param from effective_cpu_util()/sched_cpu_util()
sched/fair: Decay task PELT values during wakeup migration
sched/fair: Provide u64 read for 32-bits arch helper
sched/fair: Introduce SIS_UTIL to search idle CPU based on sum of util_avg
sched: only perform capability check on privileged operation
sched: Remove unused function group_first_cpu()
sched/fair: Remove redundant word " *"
selftests/rseq: check if libc rseq support is registered
...
|
||
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Jens Axboe
|
ed29b0b4fd |
io_uring: move to separate directory
In preparation for splitting io_uring up a bit, move it into its own top level directory. It didn't really belong in fs/ anyway, as it's not a file system only API. This adds io_uring/ and moves the core files in there, and updates the MAINTAINERS file for the new location. Signed-off-by: Jens Axboe <axboe@kernel.dk> |
||
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Paul E. McKenney
|
34bc7b454d |
Merge branch 'ctxt.2022.07.05a' into HEAD
ctxt.2022.07.05a: Linux-kernel memory model development branch. |
||
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John Keeping
|
401e4963bf |
sched/core: Always flush pending blk_plug
With CONFIG_PREEMPT_RT, it is possible to hit a deadlock between two
normal priority tasks (SCHED_OTHER, nice level zero):
INFO: task kworker/u8:0:8 blocked for more than 491 seconds.
Not tainted 5.15.49-rt46 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0 state:D stack: 0 pid: 8 ppid: 2 flags:0x00000000
Workqueue: writeback wb_workfn (flush-7:0)
[<c08a3a10>] (__schedule) from [<c08a3d84>] (schedule+0xdc/0x134)
[<c08a3d84>] (schedule) from [<c08a65a0>] (rt_mutex_slowlock_block.constprop.0+0xb8/0x174)
[<c08a65a0>] (rt_mutex_slowlock_block.constprop.0) from [<c08a6708>]
+(rt_mutex_slowlock.constprop.0+0xac/0x174)
[<c08a6708>] (rt_mutex_slowlock.constprop.0) from [<c0374d60>] (fat_write_inode+0x34/0x54)
[<c0374d60>] (fat_write_inode) from [<c0297304>] (__writeback_single_inode+0x354/0x3ec)
[<c0297304>] (__writeback_single_inode) from [<c0297998>] (writeback_sb_inodes+0x250/0x45c)
[<c0297998>] (writeback_sb_inodes) from [<c0297c20>] (__writeback_inodes_wb+0x7c/0xb8)
[<c0297c20>] (__writeback_inodes_wb) from [<c0297f24>] (wb_writeback+0x2c8/0x2e4)
[<c0297f24>] (wb_writeback) from [<c0298c40>] (wb_workfn+0x1a4/0x3e4)
[<c0298c40>] (wb_workfn) from [<c0138ab8>] (process_one_work+0x1fc/0x32c)
[<c0138ab8>] (process_one_work) from [<c0139120>] (worker_thread+0x22c/0x2d8)
[<c0139120>] (worker_thread) from [<c013e6e0>] (kthread+0x16c/0x178)
[<c013e6e0>] (kthread) from [<c01000fc>] (ret_from_fork+0x14/0x38)
Exception stack(0xc10e3fb0 to 0xc10e3ff8)
3fa0: 00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
INFO: task tar:2083 blocked for more than 491 seconds.
Not tainted 5.15.49-rt46 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:tar state:D stack: 0 pid: 2083 ppid: 2082 flags:0x00000000
[<c08a3a10>] (__schedule) from [<c08a3d84>] (schedule+0xdc/0x134)
[<c08a3d84>] (schedule) from [<c08a41b0>] (io_schedule+0x14/0x24)
[<c08a41b0>] (io_schedule) from [<c08a455c>] (bit_wait_io+0xc/0x30)
[<c08a455c>] (bit_wait_io) from [<c08a441c>] (__wait_on_bit_lock+0x54/0xa8)
[<c08a441c>] (__wait_on_bit_lock) from [<c08a44f4>] (out_of_line_wait_on_bit_lock+0x84/0xb0)
[<c08a44f4>] (out_of_line_wait_on_bit_lock) from [<c0371fb0>] (fat_mirror_bhs+0xa0/0x144)
[<c0371fb0>] (fat_mirror_bhs) from [<c0372a68>] (fat_alloc_clusters+0x138/0x2a4)
[<c0372a68>] (fat_alloc_clusters) from [<c0370b14>] (fat_alloc_new_dir+0x34/0x250)
[<c0370b14>] (fat_alloc_new_dir) from [<c03787c0>] (vfat_mkdir+0x58/0x148)
[<c03787c0>] (vfat_mkdir) from [<c0277b60>] (vfs_mkdir+0x68/0x98)
[<c0277b60>] (vfs_mkdir) from [<c027b484>] (do_mkdirat+0xb0/0xec)
[<c027b484>] (do_mkdirat) from [<c0100060>] (ret_fast_syscall+0x0/0x1c)
Exception stack(0xc2e1bfa8 to 0xc2e1bff0)
bfa0: 01ee42f0 01ee4208 01ee42f0 000041ed 00000000 00004000
bfc0: 01ee42f0 01ee4208 00000000 00000027 01ee4302 00000004 000dcb00 01ee4190
bfe0: 000dc368 bed11924 0006d4b0 b6ebddfc
Here the kworker is waiting on msdos_sb_info::s_lock which is held by
tar which is in turn waiting for a buffer which is locked waiting to be
flushed, but this operation is plugged in the kworker.
The lock is a normal struct mutex, so tsk_is_pi_blocked() will always
return false on !RT and thus the behaviour changes for RT.
It seems that the intent here is to skip blk_flush_plug() in the case
where a non-preemptible lock (such as a spinlock) has been converted to
a rtmutex on RT, which is the case covered by the SM_RTLOCK_WAIT
schedule flag. But sched_submit_work() is only called from schedule()
which is never called in this scenario, so the check can simply be
deleted.
Looking at the history of the -rt patchset, in fact this change was
present from v5.9.1-rt20 until being dropped in v5.13-rt1 as it was part
of a larger patch [1] most of which was replaced by commit
|
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Uros Bizjak
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c02d5546ea |
sched/core: Use try_cmpxchg in set_nr_{and_not,if}_polling
Use try_cmpxchg instead of cmpxchg (*ptr, old, new) != old in
set_nr_{and_not,if}_polling. x86 cmpxchg returns success in ZF flag,
so this change saves a compare after cmpxchg.
The definition of cmpxchg based fetch_or was changed in the
same way as atomic_fetch_##op definitions were changed
in
|
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Frederic Weisbecker
|
24a9c54182 |
context_tracking: Split user tracking Kconfig
Context tracking is going to be used not only to track user transitions but also idle/IRQs/NMIs. The user tracking part will then become a separate feature. Prepare Kconfig for that. [ frederic: Apply Max Filippov feedback. ] Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Nicolas Saenz Julienne <nsaenz@kernel.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com> Cc: Yu Liao <liaoyu15@huawei.com> Cc: Phil Auld <pauld@redhat.com> Cc: Paul Gortmaker<paul.gortmaker@windriver.com> Cc: Alex Belits <abelits@marvell.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> |
||
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Dietmar Eggemann
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ec4fc801a0 |
sched/fair: Rename select_idle_mask to select_rq_mask
On 21/06/2022 11:04, Vincent Donnefort wrote:
> From: Dietmar Eggemann <dietmar.eggemann@arm.com>
https://lkml.kernel.org/r/202206221253.ZVyGQvPX-lkp@intel.com discovered
that this patch doesn't build anymore (on tip sched/core or linux-next)
because of commit
|
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Dietmar Eggemann
|
bb44799949 |
sched, drivers: Remove max param from effective_cpu_util()/sched_cpu_util()
effective_cpu_util() already has a `int cpu' parameter which allows to retrieve the CPU capacity scale factor (or maximum CPU capacity) inside this function via an arch_scale_cpu_capacity(cpu). A lot of code calling effective_cpu_util() (or the shim sched_cpu_util()) needs the maximum CPU capacity, i.e. it will call arch_scale_cpu_capacity() already. But not having to pass it into effective_cpu_util() will make the EAS wake-up code easier, especially when the maximum CPU capacity reduced by the thermal pressure is passed through the EAS wake-up functions. Due to the asymmetric CPU capacity support of arm/arm64 architectures, arch_scale_cpu_capacity(int cpu) is a per-CPU variable read access via per_cpu(cpu_scale, cpu) on such a system. On all other architectures it is a a compile-time constant (SCHED_CAPACITY_SCALE). Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Vincent Guittot <vincent.guittot@linaro.org> Tested-by: Lukasz Luba <lukasz.luba@arm.com> Link: https://lkml.kernel.org/r/20220621090414.433602-4-vdonnefort@google.com |
||
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Christian Göttsche
|
700a78335f |
sched: only perform capability check on privileged operation
sched_setattr(2) issues via kernel/sched/core.c:__sched_setscheduler()
a CAP_SYS_NICE audit event unconditionally, even when the requested
operation does not require that capability / is unprivileged, i.e. for
reducing niceness.
This is relevant in connection with SELinux, where a capability check
results in a policy decision and by default a denial message on
insufficient permission is issued.
It can lead to three undesired cases:
1. A denial message is generated, even in case the operation was an
unprivileged one and thus the syscall succeeded, creating noise.
2. To avoid the noise from 1. the policy writer adds a rule to ignore
those denial messages, hiding future syscalls, where the task
performs an actual privileged operation, leading to hidden limited
functionality of that task.
3. To avoid the noise from 1. the policy writer adds a rule to allow
the task the capability CAP_SYS_NICE, while it does not need it,
violating the principle of least privilege.
Conduct privilged/unprivileged categorization first and perform a
capable test (and at most once) only if needed.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220615152505.310488-1-cgzones@googlemail.com
|
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Paul E. McKenney
|
e386b67257 |
rcu-tasks: Eliminate RCU Tasks Trace IPIs to online CPUs
Currently, the RCU Tasks Trace grace-period kthread IPIs each online CPU using smp_call_function_single() in order to track any tasks currently in RCU Tasks Trace read-side critical sections during which the corresponding task has neither blocked nor been preempted. These IPIs are annoying and are also not strictly necessary because any task that blocks or is preempted within its current RCU Tasks Trace read-side critical section will be tracked on one of the per-CPU rcu_tasks_percpu structure's ->rtp_blkd_tasks list. So the only time that this is a problem is if one of the CPUs runs through a long-duration RCU Tasks Trace read-side critical section without a context switch. Note that the task_call_func() function cannot help here because there is no safe way to identify the target task. Of course, the task_call_func() function will be very useful later, when processing the list of tasks, but it needs to know the task. This commit therefore creates a cpu_curr_snapshot() function that returns a pointer the task_struct structure of some task that happened to be running on the specified CPU more or less during the time that the cpu_curr_snapshot() function was executing. If there was no context switch during this time, this function will return a pointer to the task_struct structure of the task that was running throughout. If there was a context switch, then the outgoing task will be taken care of by RCU's context-switch hook, and the incoming task was either already taken care during some previous context switch, or it is not currently within an RCU Tasks Trace read-side critical section. And in this latter case, the grace period already started, so there is no need to wait on this task. This new cpu_curr_snapshot() function is invoked on each CPU early in the RCU Tasks Trace grace-period processing, and the resulting tasks are queued for later quiescent-state inspection. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Martin KaFai Lau <kafai@fb.com> Cc: KP Singh <kpsingh@kernel.org> |
||
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Tianchen Ding
|
f3dd3f6745 |
sched: Remove the limitation of WF_ON_CPU on wakelist if wakee cpu is idle
Wakelist can help avoid cache bouncing and offload the overhead of waker
cpu. So far, using wakelist within the same llc only happens on
WF_ON_CPU, and this limitation could be removed to further improve
wakeup performance.
The commit
|
||
|
Tianchen Ding
|
28156108fe |
sched: Fix the check of nr_running at queue wakelist
The commit
|
||
|
Peter Zijlstra
|
04193d590b |
sched: Fix balance_push() vs __sched_setscheduler()
The purpose of balance_push() is to act as a filter on task selection
in the case of CPU hotplug, specifically when taking the CPU out.
It does this by (ab)using the balance callback infrastructure, with
the express purpose of keeping all the unlikely/odd cases in a single
place.
In order to serve its purpose, the balance_push_callback needs to be
(exclusively) on the callback list at all times (noting that the
callback always places itself back on the list the moment it runs,
also noting that when the CPU goes down, regular balancing concerns
are moot, so ignoring them is fine).
And here-in lies the problem, __sched_setscheduler()'s use of
splice_balance_callbacks() takes the callbacks off the list across a
lock-break, making it possible for, an interleaving, __schedule() to
see an empty list and not get filtered.
Fixes:
|
||
|
Linus Torvalds
|
67850b7bdc |
While looking at the ptrace problems with PREEMPT_RT and the problems
of Peter Zijlstra was encountering with ptrace in his freezer rewrite I identified some cleanups to ptrace_stop that make sense on their own and move make resolving the other problems much simpler. The biggest issue is the habbit of the ptrace code to change task->__state from the tracer to suppress TASK_WAKEKILL from waking up the tracee. No other code in the kernel does that and it is straight forward to update signal_wake_up and friends to make that unnecessary. Peter's task freezer sets frozen tasks to a new state TASK_FROZEN and then it stores them by calling "wake_up_state(t, TASK_FROZEN)" relying on the fact that all stopped states except the special stop states can tolerate spurious wake up and recover their state. The state of stopped and traced tasked is changed to be stored in task->jobctl as well as in task->__state. This makes it possible for the freezer to recover tasks in these special states, as well as serving as a general cleanup. With a little more work in that direction I believe TASK_STOPPED can learn to tolerate spurious wake ups and become an ordinary stop state. The TASK_TRACED state has to remain a special state as the registers for a process are only reliably available when the process is stopped in the scheduler. Fundamentally ptrace needs acess to the saved register values of a task. There are bunch of semi-random ptrace related cleanups that were found while looking at these issues. One cleanup that deserves to be called out is from commit |
||
|
Linus Torvalds
|
44d35720c9 |
sysctl changes for v5.19-rc1
For two kernel releases now kernel/sysctl.c has been being cleaned up slowly, since the tables were grossly long, sprinkled with tons of #ifdefs and all this caused merge conflicts with one susbystem or another. This tree was put together to help try to avoid conflicts with these cleanups going on different trees at time. So nothing exciting on this pull request, just cleanups. I actually had this sysctl-next tree up since v5.18 but I missed sending a pull request for it on time during the last merge window. And so these changes have been being soaking up on sysctl-next and so linux-next for a while. The last change was merged May 4th. Most of the compile issues were reported by 0day and fixed. To help avoid a conflict with bpf folks at Daniel Borkmann's request I merged bpf-next/pr/bpf-sysctl into sysctl-next to get the effor which moves the BPF sysctls from kernel/sysctl.c to BPF core. Possible merge conflicts and known resolutions as per linux-next: bfp: https://lkml.kernel.org/r/20220414112812.652190b5@canb.auug.org.au rcu: https://lkml.kernel.org/r/20220420153746.4790d532@canb.auug.org.au powerpc: https://lkml.kernel.org/r/20220520154055.7f964b76@canb.auug.org.au -----BEGIN PGP SIGNATURE----- iQJGBAABCgAwFiEENnNq2KuOejlQLZofziMdCjCSiKcFAmKOq8ASHG1jZ3JvZkBr ZXJuZWwub3JnAAoJEM4jHQowkoinDAkQAJVo5YVM9f74UwYp4PQhTpjxJBCjRoZD z1u9bp5rMj2ujTC8Fr7VmzKaHrb8+r1C1WvCvZtIzemYNB4lZUrHpVDYfXuXiPRB ihPmEjhlPO5PFBx6cVCpI3cu9bEhG00rLc1QXnABx/pXwNPcOTJAGZJVamZvqubk chjgZrb7N+adHPfvS55v1+zpwdeKfpp5U3zuu5qlT/nn0GS0HCVzOj5fj4oC4wtJ IqfUubo+FX50Ga58yQABWNrjaPD9Crykz5ohVazy3ElQl0hJ4VsK65ct3blqc2vz 1Bb8kPpWuv6aZ5nr1lCVE8qvF4ZIL33ySvpg5BSdWLQEDrBbSpzvJe9Yn7wgR+eq y7fhpO24+zRM82EoDMEvyxX9u1n1RsvoXRtf3ds9BGf63MUxk8a1cgjlU6vuyO2U JhDmfM1xzdKvPoY4COOnHzcAiIqzItTqKd09N5y0cahmYstROU8lvp9huhTAHqk1 SjQMbLIZG7OnX8ZeQcR1EB8sq/IOPZT48ejj0iJmQ8FyMaep71MOQLYyLPAq4lgh JHXm8P6QdB57jfJbqAeNSyZoK0qdxOUR/83Zcah7Jjns6vkju1DNatEsaEEI2y2M 4n7/rkHeZ3TyFHBUX4e9FomKvGLsAalDBRiqsuxLSOPMU8rGrNLAslOAtKwvp90X 4ht3M2VP098l =btwh -----END PGP SIGNATURE----- Merge tag 'sysctl-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull sysctl updates from Luis Chamberlain: "For two kernel releases now kernel/sysctl.c has been being cleaned up slowly, since the tables were grossly long, sprinkled with tons of #ifdefs and all this caused merge conflicts with one susbystem or another. This tree was put together to help try to avoid conflicts with these cleanups going on different trees at time. So nothing exciting on this pull request, just cleanups. Thanks a lot to the Uniontech and Huawei folks for doing some of this nasty work" * tag 'sysctl-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (28 commits) sched: Fix build warning without CONFIG_SYSCTL reboot: Fix build warning without CONFIG_SYSCTL kernel/kexec_core: move kexec_core sysctls into its own file sysctl: minor cleanup in new_dir() ftrace: fix building with SYSCTL=y but DYNAMIC_FTRACE=n fs/proc: Introduce list_for_each_table_entry for proc sysctl mm: fix unused variable kernel warning when SYSCTL=n latencytop: move sysctl to its own file ftrace: fix building with SYSCTL=n but DYNAMIC_FTRACE=y ftrace: Fix build warning ftrace: move sysctl_ftrace_enabled to ftrace.c kernel/do_mount_initrd: move real_root_dev sysctls to its own file kernel/delayacct: move delayacct sysctls to its own file kernel/acct: move acct sysctls to its own file kernel/panic: move panic sysctls to its own file kernel/lockdep: move lockdep sysctls to its own file mm: move page-writeback sysctls to their own file mm: move oom_kill sysctls to their own file kernel/reboot: move reboot sysctls to its own file sched: Move energy_aware sysctls to topology.c ... |
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|
Linus Torvalds
|
6f3f04c190 |
Scheduler changes in this cycle were:
- Updates to scheduler metrics:
- PELT fixes & enhancements
- PSI fixes & enhancements
- Refactor cpu_util_without()
- Updates to instrumentation/debugging:
- Remove sched_trace_*() helper functions - can be done via debug info
- Fix double update_rq_clock() warnings
- Introduce & use "preemption model accessors" to simplify some of
the Kconfig complexity.
- Make softirq handling RT-safe.
- Misc smaller fixes & cleanups.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Updates to scheduler metrics:
- PELT fixes & enhancements
- PSI fixes & enhancements
- Refactor cpu_util_without()
- Updates to instrumentation/debugging:
- Remove sched_trace_*() helper functions - can be done via debug
info
- Fix double update_rq_clock() warnings
- Introduce & use "preemption model accessors" to simplify some of the
Kconfig complexity.
- Make softirq handling RT-safe.
- Misc smaller fixes & cleanups.
* tag 'sched-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
topology: Remove unused cpu_cluster_mask()
sched: Reverse sched_class layout
sched/deadline: Remove superfluous rq clock update in push_dl_task()
sched/core: Avoid obvious double update_rq_clock warning
smp: Make softirq handling RT safe in flush_smp_call_function_queue()
smp: Rename flush_smp_call_function_from_idle()
sched: Fix missing prototype warnings
sched/fair: Remove cfs_rq_tg_path()
sched/fair: Remove sched_trace_*() helper functions
sched/fair: Refactor cpu_util_without()
sched/fair: Revise comment about lb decision matrix
sched/psi: report zeroes for CPU full at the system level
sched/fair: Delete useless condition in tg_unthrottle_up()
sched/fair: Fix cfs_rq_clock_pelt() for throttled cfs_rq
sched/fair: Move calculate of avg_load to a better location
mailmap: Update my email address to @redhat.com
MAINTAINERS: Add myself as scheduler topology reviewer
psi: Fix trigger being fired unexpectedly at initial
ftrace: Use preemption model accessors for trace header printout
kcsan: Use preemption model accessors
|
||
|
Linus Torvalds
|
1e57930e9f |
RCU pull request for v5.19
This pull request contains the following branches: docs.2022.04.20a: Documentation updates. fixes.2022.04.20a: Miscellaneous fixes. nocb.2022.04.11b: Callback-offloading updates, mainly simplifications. rcu-tasks.2022.04.11b: RCU-tasks updates, including some -rt fixups, handling of systems with sparse CPU numbering, and a fix for a boot-time race-condition failure. srcu.2022.05.03a: Put SRCU on a memory diet in order to reduce the size of the srcu_struct structure. torture.2022.04.11b: Torture-test updates fixing some bugs in tests and closing some testing holes. torture-tasks.2022.04.20a: Torture-test updates for the RCU tasks flavors, most notably ensuring that building rcutorture and friends does not change the RCU-tasks-related Kconfig options. torturescript.2022.04.20a: Torture-test scripting updates. exp.2022.05.11a: Expedited grace-period updates, most notably providing milliseconds-scale (not all that) soft real-time response from synchronize_rcu_expedited(). This is also the first time in almost 30 years of RCU that someone other than me has pushed for a reduction in the RCU CPU stall-warning timeout, in this case by more than three orders of magnitude from 21 seconds to 20 milliseconds. This tighter timeout applies only to expedited grace periods. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEbK7UrM+RBIrCoViJnr8S83LZ+4wFAmKG2zcTHHBhdWxtY2tA a2VybmVsLm9yZwAKCRCevxLzctn7jGXgD/90xtRtZyN0umlN/IOBBn8fIOM+BAMu 5k3ef6wLsXKXlLO13WTjSitypX9LEFwytTeVhEyN4ODeX0cI9mUmts6Z8/6sV92D fN8vqTavveE7m5YfFfLRvDRfVHpB0LpLMM+V0qWPu/F8dWPDKA0225rX9IC7iICP LkxCuNVNzJ0cLaVTvsUWlxMdHcogydXZb1gPDVRhnR6iVFWCBtL4RRpU41CoSNh4 fWRSLQak6OhZRFE7hVoLQhZyLE0GIw1fuUJgj2fCllhgGogDx78FQ8jHdDzMEhVk cD4Yel5vUPiy2AKphGfi28bKFYcyhVBnD/Jq733VJV0/szyddxNbz0xKpEA0/8qh w1T7IjBN6MAKHSh0uUitm6U24VN13m4r30HrUQSpp71VFZkUD4QS6TismKsaRNjR lK4q2QKBprBb3Hv7KPAGYT1Us3aS7qLPrgPf3gzSxL1aY5QV0A5UpPP6RKTLbWPl CEQxEno6g5LTHwKd5QD74dG8ccphg9377lDMJpeesYShBqlLNrNWCxqJoZk2HnSf f2dTQeQWrtRJjeTGy/4cfONCGZTghE0Pch43XMzLLt3ZTuDc8FVM0t3Xs9J5Kg22 zmThQh6LRXTGjrb1vLiOrjPf5JaTnX2Sz8OUJTo/ZxwcixxP/mj8Ja+W81NjfqnK LLZ1D6UN4a8n9A== =4spH -----END PGP SIGNATURE----- Merge tag 'rcu.2022.05.19a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull RCU update from Paul McKenney: - Documentation updates - Miscellaneous fixes - Callback-offloading updates, mainly simplifications - RCU-tasks updates, including some -rt fixups, handling of systems with sparse CPU numbering, and a fix for a boot-time race-condition failure - Put SRCU on a memory diet in order to reduce the size of the srcu_struct structure - Torture-test updates fixing some bugs in tests and closing some testing holes - Torture-test updates for the RCU tasks flavors, most notably ensuring that building rcutorture and friends does not change the RCU-tasks-related Kconfig options - Torture-test scripting updates - Expedited grace-period updates, most notably providing milliseconds-scale (not all that) soft real-time response from synchronize_rcu_expedited(). This is also the first time in almost 30 years of RCU that someone other than me has pushed for a reduction in the RCU CPU stall-warning timeout, in this case by more than three orders of magnitude from 21 seconds to 20 milliseconds. This tighter timeout applies only to expedited grace periods * tag 'rcu.2022.05.19a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (80 commits) rcu: Move expedited grace period (GP) work to RT kthread_worker rcu: Introduce CONFIG_RCU_EXP_CPU_STALL_TIMEOUT srcu: Drop needless initialization of sdp in srcu_gp_start() srcu: Prevent expedited GPs and blocking readers from consuming CPU srcu: Add contention check to call_srcu() srcu_data ->lock acquisition srcu: Automatically determine size-transition strategy at boot rcutorture: Make torture.sh allow for --kasan rcutorture: Make torture.sh refscale and rcuscale specify Tasks Trace RCU rcutorture: Make kvm.sh allow more memory for --kasan runs torture: Save "make allmodconfig" .config file scftorture: Remove extraneous "scf" from per_version_boot_params rcutorture: Adjust scenarios' Kconfig options for CONFIG_PREEMPT_DYNAMIC torture: Enable CSD-lock stall reports for scftorture torture: Skip vmlinux check for kvm-again.sh runs scftorture: Adjust for TASKS_RCU Kconfig option being selected rcuscale: Allow rcuscale without RCU Tasks Rude/Trace rcuscale: Allow rcuscale without RCU Tasks refscale: Allow refscale without RCU Tasks Rude/Trace refscale: Allow refscale without RCU Tasks rcutorture: Allow specifying per-scenario stat_interval ... |
||
|
Peter Zijlstra
|
546a3fee17 |
sched: Reverse sched_class layout
Because GCC-12 is fully stupid about array bounds and it's just really hard to get a solid array definition from a linker script, flip the array order to avoid needing negative offsets :-/ This makes the whole relational pointer magic a little less obvious, but alas. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/YoOLLmLG7HRTXeEm@hirez.programming.kicks-ass.net |
||
|
Delyan Kratunov
|
9c2136be08 |
sched/tracing: Append prev_state to tp args instead
Commit |
||
|
Eric W. Biederman
|
2500ad1c7f |
ptrace: Don't change __state
Stop playing with tsk->__state to remove TASK_WAKEKILL while a ptrace command is executing. Instead remove TASK_WAKEKILL from the definition of TASK_TRACED, and implement a new jobctl flag TASK_PTRACE_FROZEN. This new flag is set in jobctl_freeze_task and cleared when ptrace_stop is awoken or in jobctl_unfreeze_task (when ptrace_stop remains asleep). In signal_wake_up add __TASK_TRACED to state along with TASK_WAKEKILL when the wake up is for a fatal signal. Skip adding __TASK_TRACED when TASK_PTRACE_FROZEN is not set. This has the same effect as changing TASK_TRACED to __TASK_TRACED as all of the wake_ups that use TASK_KILLABLE go through signal_wake_up. Handle a ptrace_stop being called with a pending fatal signal. Previously it would have been handled by schedule simply failing to sleep. As TASK_WAKEKILL is no longer part of TASK_TRACED schedule will sleep with a fatal_signal_pending. The code in signal_wake_up guarantees that the code will be awaked by any fatal signal that codes after TASK_TRACED is set. Previously the __state value of __TASK_TRACED was changed to TASK_RUNNING when woken up or back to TASK_TRACED when the code was left in ptrace_stop. Now when woken up ptrace_stop now clears JOBCTL_PTRACE_FROZEN and when left sleeping ptrace_unfreezed_traced clears JOBCTL_PTRACE_FROZEN. Tested-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Link: https://lkml.kernel.org/r/20220505182645.497868-10-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
||
|
Hao Jia
|
2679a83731 |
sched/core: Avoid obvious double update_rq_clock warning
When we use raw_spin_rq_lock() to acquire the rq lock and have to
update the rq clock while holding the lock, the kernel may issue
a WARN_DOUBLE_CLOCK warning.
Since we directly use raw_spin_rq_lock() to acquire rq lock instead of
rq_lock(), there is no corresponding change to rq->clock_update_flags.
In particular, we have obtained the rq lock of other CPUs, the
rq->clock_update_flags of this CPU may be RQCF_UPDATED at this time, and
then calling update_rq_clock() will trigger the WARN_DOUBLE_CLOCK warning.
So we need to clear RQCF_UPDATED of rq->clock_update_flags to avoid
the WARN_DOUBLE_CLOCK warning.
For the sched_rt_period_timer() and migrate_task_rq_dl() cases
we simply replace raw_spin_rq_lock()/raw_spin_rq_unlock() with
rq_lock()/rq_unlock().
For the {pull,push}_{rt,dl}_task() cases, we add the
double_rq_clock_clear_update() function to clear RQCF_UPDATED of
rq->clock_update_flags, and call double_rq_clock_clear_update()
before double_lock_balance()/double_rq_lock() returns to avoid the
WARN_DOUBLE_CLOCK warning.
Some call trace reports:
Call Trace 1:
<IRQ>
sched_rt_period_timer+0x10f/0x3a0
? enqueue_top_rt_rq+0x110/0x110
__hrtimer_run_queues+0x1a9/0x490
hrtimer_interrupt+0x10b/0x240
__sysvec_apic_timer_interrupt+0x8a/0x250
sysvec_apic_timer_interrupt+0x9a/0xd0
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x12/0x20
Call Trace 2:
<TASK>
activate_task+0x8b/0x110
push_rt_task.part.108+0x241/0x2c0
push_rt_tasks+0x15/0x30
finish_task_switch+0xaa/0x2e0
? __switch_to+0x134/0x420
__schedule+0x343/0x8e0
? hrtimer_start_range_ns+0x101/0x340
schedule+0x4e/0xb0
do_nanosleep+0x8e/0x160
hrtimer_nanosleep+0x89/0x120
? hrtimer_init_sleeper+0x90/0x90
__x64_sys_nanosleep+0x96/0xd0
do_syscall_64+0x34/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Call Trace 3:
<TASK>
deactivate_task+0x93/0xe0
pull_rt_task+0x33e/0x400
balance_rt+0x7e/0x90
__schedule+0x62f/0x8e0
do_task_dead+0x3f/0x50
do_exit+0x7b8/0xbb0
do_group_exit+0x2d/0x90
get_signal+0x9df/0x9e0
? preempt_count_add+0x56/0xa0
? __remove_hrtimer+0x35/0x70
arch_do_signal_or_restart+0x36/0x720
? nanosleep_copyout+0x39/0x50
? do_nanosleep+0x131/0x160
? audit_filter_inodes+0xf5/0x120
exit_to_user_mode_prepare+0x10f/0x1e0
syscall_exit_to_user_mode+0x17/0x30
do_syscall_64+0x40/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Call Trace 4:
update_rq_clock+0x128/0x1a0
migrate_task_rq_dl+0xec/0x310
set_task_cpu+0x84/0x1e4
try_to_wake_up+0x1d8/0x5c0
wake_up_process+0x1c/0x30
hrtimer_wakeup+0x24/0x3c
__hrtimer_run_queues+0x114/0x270
hrtimer_interrupt+0xe8/0x244
arch_timer_handler_phys+0x30/0x50
handle_percpu_devid_irq+0x88/0x140
generic_handle_domain_irq+0x40/0x60
gic_handle_irq+0x48/0xe0
call_on_irq_stack+0x2c/0x60
do_interrupt_handler+0x80/0x84
Steps to reproduce:
1. Enable CONFIG_SCHED_DEBUG when compiling the kernel
2. echo 1 > /sys/kernel/debug/clear_warn_once
echo "WARN_DOUBLE_CLOCK" > /sys/kernel/debug/sched/features
echo "NO_RT_PUSH_IPI" > /sys/kernel/debug/sched/features
3. Run some rt/dl tasks that periodically work and sleep, e.g.
Create 2*n rt or dl (90% running) tasks via rt-app (on a system
with n CPUs), and Dietmar Eggemann reports Call Trace 4 when running
on PREEMPT_RT kernel.
Signed-off-by: Hao Jia <jiahao.os@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/20220430085843.62939-2-jiahao.os@bytedance.com
|
||
|
YueHaibing
|
494dcdf46e |
sched: Fix build warning without CONFIG_SYSCTL
IF CONFIG_SYSCTL is n, build warn:
kernel/sched/core.c:1782:12: warning: ‘sysctl_sched_uclamp_handler’ defined but not used [-Wunused-function]
static int sysctl_sched_uclamp_handler(struct ctl_table *table, int write,
^~~~~~~~~~~~~~~~~~~~~~~~~~~
sysctl_sched_uclamp_handler() is used while CONFIG_SYSCTL enabled,
wrap all related code with CONFIG_SYSCTL to fix this.
Fixes:
|
||
|
Ingo Molnar
|
d70522fc54 |
Linux 5.18-rc5
-----BEGIN PGP SIGNATURE----- iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmJu9FYeHHRvcnZhbGRz QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGAyEH/16xtJSpLmLwrQzG o+4ToQxSQ+/9UHyu0RTEvHg2THm9/8emtIuYyc/5FgdoWctcSa3AaDcveWmuWmkS KYcdhfJsaEqjNHS3OPYXN84fmo9Hel7263shu5+IYmP/sN0DfQp6UWTryX1q4B3Q 4Pdutkuq63Uwd8nBZ5LXQBumaBrmkkuMgWEdT4+6FOo1mPzwdIGBxCuz1UsNNl5k chLWxkQfe2eqgWbYJrgCQfrVdORXVtoU2fGilZUNrHRVGkkldXkkz5clJfapyZD3 odmZCEbrE4GPKgZwCmDERMfD1hzhZDtYKiHfOQ506szH5ykJjPBcOjHed7dA60eB J3+wdek= =39Ca -----END PGP SIGNATURE----- Merge tag 'v5.18-rc5' into sched/core to pull in fixes & to resolve a conflict - sched/core is on a pretty old -rc1 base - refresh it to include recent fixes. - this also allows up to resolve a (trivial) .mailmap conflict Conflicts: .mailmap Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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|
Thomas Gleixner
|
16bf5a5e1e |
smp: Rename flush_smp_call_function_from_idle()
This is invoked from the stopper thread too, which is definitely not idle. Rename it to flush_smp_call_function_queue() and fixup the callers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220413133024.305001096@linutronix.de |
||
|
Thomas Gleixner
|
d664e39912 |
sched: Fix missing prototype warnings
A W=1 build emits more than a dozen missing prototype warnings related to scheduler and scheduler specific includes. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220413133024.249118058@linutronix.de |
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|
Zhen Ni
|
3267e0156c |
sched: Move uclamp_util sysctls to core.c
move uclamp_util sysctls to core.c and use the new register_sysctl_init() to register the sysctl interface. Signed-off-by: Zhen Ni <nizhen@uniontech.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> |
||
|
Zhen Ni
|
d9ab0e63fa |
sched: Move rt_period/runtime sysctls to rt.c
move rt_period/runtime sysctls to rt.c and use the new register_sysctl_init() to register the sysctl interface. Signed-off-by: Zhen Ni <nizhen@uniontech.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> |
||
|
Zhen Ni
|
f5ef06d58b |
sched: Move schedstats sysctls to core.c
move schedstats sysctls to core.c and use the new register_sysctl_init() to register the sysctl interface. Signed-off-by: Zhen Ni <nizhen@uniontech.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> |
||
|
Valentin Schneider
|
cfe43f478b |
preempt/dynamic: Introduce preemption model accessors
CONFIG_PREEMPT{_NONE, _VOLUNTARY} designate either:
o The build-time preemption model when !PREEMPT_DYNAMIC
o The default boot-time preemption model when PREEMPT_DYNAMIC
IOW, using those on PREEMPT_DYNAMIC kernels is meaningless - the actual
model could have been set to something else by the "preempt=foo" cmdline
parameter. Same problem applies to CONFIG_PREEMPTION.
Introduce a set of helpers to determine the actual preemption model used by
the live kernel.
Suggested-by: Marco Elver <elver@google.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20211112185203.280040-3-valentin.schneider@arm.com
|
||
|
Sebastian Andrzej Siewior
|
386ef214c3 |
sched: Teach the forced-newidle balancer about CPU affinity limitation.
try_steal_cookie() looks at task_struct::cpus_mask to decide if the
task could be moved to `this' CPU. It ignores that the task might be in
a migration disabled section while not on the CPU. In this case the task
must not be moved otherwise per-CPU assumption are broken.
Use is_cpu_allowed(), as suggested by Peter Zijlstra, to decide if the a
task can be moved.
Fixes:
|
||
|
Peter Zijlstra
|
5b6547ed97 |
sched/core: Fix forceidle balancing
Steve reported that ChromeOS encounters the forceidle balancer being
ran from rt_mutex_setprio()'s balance_callback() invocation and
explodes.
Now, the forceidle balancer gets queued every time the idle task gets
selected, set_next_task(), which is strictly too often.
rt_mutex_setprio() also uses set_next_task() in the 'change' pattern:
queued = task_on_rq_queued(p); /* p->on_rq == TASK_ON_RQ_QUEUED */
running = task_current(rq, p); /* rq->curr == p */
if (queued)
dequeue_task(...);
if (running)
put_prev_task(...);
/* change task properties */
if (queued)
enqueue_task(...);
if (running)
set_next_task(...);
However, rt_mutex_setprio() will explicitly not run this pattern on
the idle task (since priority boosting the idle task is quite insane).
Most other 'change' pattern users are pidhash based and would also not
apply to idle.
Also, the change pattern doesn't contain a __balance_callback()
invocation and hence we could have an out-of-band balance-callback,
which *should* trigger the WARN in rq_pin_lock() (which guards against
this exact anti-pattern).
So while none of that explains how this happens, it does indicate that
having it in set_next_task() might not be the most robust option.
Instead, explicitly queue the forceidle balancer from pick_next_task()
when it does indeed result in forceidle selection. Having it here,
ensures it can only be triggered under the __schedule() rq->lock
instance, and hence must be ran from that context.
This also happens to clean up the code a little, so win-win.
Fixes:
|
||
|
Linus Torvalds
|
3bf03b9a08 |
Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:
- A few misc subsystems: kthread, scripts, ntfs, ocfs2, block, and vfs
- Most the MM patches which precede the patches in Willy's tree: kasan,
pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
sparsemem, vmalloc, pagealloc, memory-failure, mlock, hugetlb,
userfaultfd, vmscan, compaction, mempolicy, oom-kill, migration, thp,
cma, autonuma, psi, ksm, page-poison, madvise, memory-hotplug, rmap,
zswap, uaccess, ioremap, highmem, cleanups, kfence, hmm, and damon.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (227 commits)
mm/damon/sysfs: remove repeat container_of() in damon_sysfs_kdamond_release()
Docs/ABI/testing: add DAMON sysfs interface ABI document
Docs/admin-guide/mm/damon/usage: document DAMON sysfs interface
selftests/damon: add a test for DAMON sysfs interface
mm/damon/sysfs: support DAMOS stats
mm/damon/sysfs: support DAMOS watermarks
mm/damon/sysfs: support schemes prioritization
mm/damon/sysfs: support DAMOS quotas
mm/damon/sysfs: support DAMON-based Operation Schemes
mm/damon/sysfs: support the physical address space monitoring
mm/damon/sysfs: link DAMON for virtual address spaces monitoring
mm/damon: implement a minimal stub for sysfs-based DAMON interface
mm/damon/core: add number of each enum type values
mm/damon/core: allow non-exclusive DAMON start/stop
Docs/damon: update outdated term 'regions update interval'
Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling
Docs/vm/damon: call low level monitoring primitives the operations
mm/damon: remove unnecessary CONFIG_DAMON option
mm/damon/paddr,vaddr: remove damon_{p,v}a_{target_valid,set_operations}()
mm/damon/dbgfs-test: fix is_target_id() change
...
|
||
|
Huang Ying
|
c574bbe917 |
NUMA balancing: optimize page placement for memory tiering system
With the advent of various new memory types, some machines will have multiple types of memory, e.g. DRAM and PMEM (persistent memory). The memory subsystem of these machines can be called memory tiering system, because the performance of the different types of memory are usually different. In such system, because of the memory accessing pattern changing etc, some pages in the slow memory may become hot globally. So in this patch, the NUMA balancing mechanism is enhanced to optimize the page placement among the different memory types according to hot/cold dynamically. In a typical memory tiering system, there are CPUs, fast memory and slow memory in each physical NUMA node. The CPUs and the fast memory will be put in one logical node (called fast memory node), while the slow memory will be put in another (faked) logical node (called slow memory node). That is, the fast memory is regarded as local while the slow memory is regarded as remote. So it's possible for the recently accessed pages in the slow memory node to be promoted to the fast memory node via the existing NUMA balancing mechanism. The original NUMA balancing mechanism will stop to migrate pages if the free memory of the target node becomes below the high watermark. This is a reasonable policy if there's only one memory type. But this makes the original NUMA balancing mechanism almost do not work to optimize page placement among different memory types. Details are as follows. It's the common cases that the working-set size of the workload is larger than the size of the fast memory nodes. Otherwise, it's unnecessary to use the slow memory at all. So, there are almost always no enough free pages in the fast memory nodes, so that the globally hot pages in the slow memory node cannot be promoted to the fast memory node. To solve the issue, we have 2 choices as follows, a. Ignore the free pages watermark checking when promoting hot pages from the slow memory node to the fast memory node. This will create some memory pressure in the fast memory node, thus trigger the memory reclaiming. So that, the cold pages in the fast memory node will be demoted to the slow memory node. b. Define a new watermark called wmark_promo which is higher than wmark_high, and have kswapd reclaiming pages until free pages reach such watermark. The scenario is as follows: when we want to promote hot-pages from a slow memory to a fast memory, but fast memory's free pages would go lower than high watermark with such promotion, we wake up kswapd with wmark_promo watermark in order to demote cold pages and free us up some space. So, next time we want to promote hot-pages we might have a chance of doing so. The choice "a" may create high memory pressure in the fast memory node. If the memory pressure of the workload is high, the memory pressure may become so high that the memory allocation latency of the workload is influenced, e.g. the direct reclaiming may be triggered. The choice "b" works much better at this aspect. If the memory pressure of the workload is high, the hot pages promotion will stop earlier because its allocation watermark is higher than that of the normal memory allocation. So in this patch, choice "b" is implemented. A new zone watermark (WMARK_PROMO) is added. Which is larger than the high watermark and can be controlled via watermark_scale_factor. In addition to the original page placement optimization among sockets, the NUMA balancing mechanism is extended to be used to optimize page placement according to hot/cold among different memory types. So the sysctl user space interface (numa_balancing) is extended in a backward compatible way as follow, so that the users can enable/disable these functionality individually. The sysctl is converted from a Boolean value to a bits field. The definition of the flags is, - 0: NUMA_BALANCING_DISABLED - 1: NUMA_BALANCING_NORMAL - 2: NUMA_BALANCING_MEMORY_TIERING We have tested the patch with the pmbench memory accessing benchmark with the 80:20 read/write ratio and the Gauss access address distribution on a 2 socket Intel server with Optane DC Persistent Memory Model. The test results shows that the pmbench score can improve up to 95.9%. Thanks Andrew Morton to help fix the document format error. Link: https://lkml.kernel.org/r/20220221084529.1052339-3-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Yang Shi <shy828301@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Rik van Riel <riel@surriel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Wei Xu <weixugc@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: zhongjiang-ali <zhongjiang-ali@linux.alibaba.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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|
Linus Torvalds
|
3fe2f7446f |
Changes in this cycle were:
- Cleanups for SCHED_DEADLINE
- Tracing updates/fixes
- CPU Accounting fixes
- First wave of changes to optimize the overhead of the scheduler build,
from the fast-headers tree - including placeholder *_api.h headers for
later header split-ups.
- Preempt-dynamic using static_branch() for ARM64
- Isolation housekeeping mask rework; preperatory for further changes
- NUMA-balancing: deal with CPU-less nodes
- NUMA-balancing: tune systems that have multiple LLC cache domains per node (eg. AMD)
- Updates to RSEQ UAPI in preparation for glibc usage
- Lots of RSEQ/selftests, for same
- Add Suren as PSI co-maintainer
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2022-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Cleanups for SCHED_DEADLINE
- Tracing updates/fixes
- CPU Accounting fixes
- First wave of changes to optimize the overhead of the scheduler
build, from the fast-headers tree - including placeholder *_api.h
headers for later header split-ups.
- Preempt-dynamic using static_branch() for ARM64
- Isolation housekeeping mask rework; preperatory for further changes
- NUMA-balancing: deal with CPU-less nodes
- NUMA-balancing: tune systems that have multiple LLC cache domains per
node (eg. AMD)
- Updates to RSEQ UAPI in preparation for glibc usage
- Lots of RSEQ/selftests, for same
- Add Suren as PSI co-maintainer
* tag 'sched-core-2022-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (81 commits)
sched/headers: ARM needs asm/paravirt_api_clock.h too
sched/numa: Fix boot crash on arm64 systems
headers/prep: Fix header to build standalone: <linux/psi.h>
sched/headers: Only include <linux/entry-common.h> when CONFIG_GENERIC_ENTRY=y
cgroup: Fix suspicious rcu_dereference_check() usage warning
sched/preempt: Tell about PREEMPT_DYNAMIC on kernel headers
sched/topology: Remove redundant variable and fix incorrect type in build_sched_domains
sched/deadline,rt: Remove unused parameter from pick_next_[rt|dl]_entity()
sched/deadline,rt: Remove unused functions for !CONFIG_SMP
sched/deadline: Use __node_2_[pdl|dle]() and rb_first_cached() consistently
sched/deadline: Merge dl_task_can_attach() and dl_cpu_busy()
sched/deadline: Move bandwidth mgmt and reclaim functions into sched class source file
sched/deadline: Remove unused def_dl_bandwidth
sched/tracing: Report TASK_RTLOCK_WAIT tasks as TASK_UNINTERRUPTIBLE
sched/tracing: Don't re-read p->state when emitting sched_switch event
sched/rt: Plug rt_mutex_setprio() vs push_rt_task() race
sched/cpuacct: Remove redundant RCU read lock
sched/cpuacct: Optimize away RCU read lock
sched/cpuacct: Fix charge percpu cpuusage
sched/headers: Reorganize, clean up and optimize kernel/sched/sched.h dependencies
...
|
||
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Linus Torvalds
|
616355cc81 |
for-5.18/block-2022-03-18
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Ingo Molnar
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a7b2553b5e |
sched/headers: Only include <linux/entry-common.h> when CONFIG_GENERIC_ENTRY=y
This header is not (yet) standalone. Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar
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ccacfe56d7 |
Merge branch 'sched/fast-headers' into sched/core
Merge the scheduler build speedup of the fast-headers tree.
Cumulative scheduler (kernel/sched/) build time speedup on a
Linux distribution's config, which enables all scheduler features,
compared to the vanilla kernel:
_____________________________________________________________________________
|
| Vanilla kernel (v5.13-rc7):
|_____________________________________________________________________________
|
| Performance counter stats for 'make -j96 kernel/sched/' (3 runs):
|
| 126,975,564,374 instructions # 1.45 insn per cycle ( +- 0.00% )
| 87,637,847,671 cycles # 3.959 GHz ( +- 0.30% )
| 22,136.96 msec cpu-clock # 7.499 CPUs utilized ( +- 0.29% )
|
| 2.9520 +- 0.0169 seconds time elapsed ( +- 0.57% )
|_____________________________________________________________________________
|
| Patched kernel:
|_____________________________________________________________________________
|
| Performance counter stats for 'make -j96 kernel/sched/' (3 runs):
|
| 50,420,496,914 instructions # 1.47 insn per cycle ( +- 0.00% )
| 34,234,322,038 cycles # 3.946 GHz ( +- 0.31% )
| 8,675.81 msec cpu-clock # 3.053 CPUs utilized ( +- 0.45% )
|
| 2.8420 +- 0.0181 seconds time elapsed ( +- 0.64% )
|_____________________________________________________________________________
Summary:
- CPU time used to build the scheduler dropped by -60.9%, a reduction
from 22.1 clock-seconds to 8.7 clock-seconds.
- Wall-clock time to build the scheduler dropped by -3.9%, a reduction
from 2.95 seconds to 2.84 seconds.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
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Dietmar Eggemann
|
772b6539fd |
sched/deadline: Merge dl_task_can_attach() and dl_cpu_busy()
Both functions are doing almost the same, that is checking if admission control is still respected. With exclusive cpusets, dl_task_can_attach() checks if the destination cpuset (i.e. its root domain) has enough CPU capacity to accommodate the task. dl_cpu_busy() checks if there is enough CPU capacity in the cpuset in case the CPU is hot-plugged out. dl_task_can_attach() is used to check if a task can be admitted while dl_cpu_busy() is used to check if a CPU can be hotplugged out. Make dl_cpu_busy() able to deal with a task and use it instead of dl_task_can_attach() in task_can_attach(). Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20220302183433.333029-4-dietmar.eggemann@arm.com |
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Dietmar Eggemann
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eb77cf1c15 |
sched/deadline: Remove unused def_dl_bandwidth
Since commit
|
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Valentin Schneider
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fa2c3254d7 |
sched/tracing: Don't re-read p->state when emitting sched_switch event
As of commit
|
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Ingo Molnar
|
e66f6481a8 |
sched/headers: Reorganize, clean up and optimize kernel/sched/core.c dependencies
Use all generic headers from kernel/sched/sched.h that are required for it to build. Sort the sections alphabetically. Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Peter Zijlstra <peterz@infradead.org> |
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Ingo Molnar
|
b9e9c6ca6e |
sched/headers: Standardize kernel/sched/sched.h header dependencies
kernel/sched/sched.h is a weird mix of ad-hoc headers included in the middle of the header. Two of them rely on being included in the middle of kernel/sched/sched.h, due to definitions they require: - "stat.h" needs the rq definitions. - "autogroup.h" needs the task_group definition. Move the inclusion of these two files out of kernel/sched/sched.h, and include them in all files that require them. Move of the rest of the header dependencies to the top of the kernel/sched/sched.h file. Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Peter Zijlstra <peterz@infradead.org> |
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Ingo Molnar
|
6255b48aeb |
Linux 5.17-rc5
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