History log of /openbmc/linux/kernel/sched/debug.c (Results 176 – 200 of 957)
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# fd531024 11-May-2021 Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-next into drm-misc-next

Backmerging to get v5.12 fixes. Requested for vmwgfx.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>


# c55b44c9 11-May-2021 Maxime Ripard <maxime@cerno.tech>

Merge drm/drm-fixes into drm-misc-fixes

Start this new release drm-misc-fixes branch

Signed-off-by: Maxime Ripard <maxime@cerno.tech>


# d0034a7a 04-May-2021 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge branch 'next' into for-linus

Prepare input updates for 5.13 merge window.


# 16b3d0cf 28-Apr-2021 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'sched-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:

- Clean up SCHED_DEBUG: move the decades old mess of sysctl, pro

Merge tag 'sched-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:

- Clean up SCHED_DEBUG: move the decades old mess of sysctl, procfs and
debugfs interfaces to a unified debugfs interface.

- Signals: Allow caching one sigqueue object per task, to improve
performance & latencies.

- Improve newidle_balance() irq-off latencies on systems with a large
number of CPU cgroups.

- Improve energy-aware scheduling

- Improve the PELT metrics for certain workloads

- Reintroduce select_idle_smt() to improve load-balancing locality -
but without the previous regressions

- Add 'scheduler latency debugging': warn after long periods of pending
need_resched. This is an opt-in feature that requires the enabling of
the LATENCY_WARN scheduler feature, or the use of the
resched_latency_warn_ms=xx boot parameter.

- CPU hotplug fixes for HP-rollback, and for the 'fail' interface. Fix
remaining balance_push() vs. hotplug holes/races

- PSI fixes, plus allow /proc/pressure/ files to be written by
CAP_SYS_RESOURCE tasks as well

- Fix/improve various load-balancing corner cases vs. capacity margins

- Fix sched topology on systems with NUMA diameter of 3 or above

- Fix PF_KTHREAD vs to_kthread() race

- Minor rseq optimizations

- Misc cleanups, optimizations, fixes and smaller updates

* tag 'sched-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (61 commits)
cpumask/hotplug: Fix cpu_dying() state tracking
kthread: Fix PF_KTHREAD vs to_kthread() race
sched/debug: Fix cgroup_path[] serialization
sched,psi: Handle potential task count underflow bugs more gracefully
sched: Warn on long periods of pending need_resched
sched/fair: Move update_nohz_stats() to the CONFIG_NO_HZ_COMMON block to simplify the code & fix an unused function warning
sched/debug: Rename the sched_debug parameter to sched_verbose
sched,fair: Alternative sched_slice()
sched: Move /proc/sched_debug to debugfs
sched,debug: Convert sysctl sched_domains to debugfs
debugfs: Implement debugfs_create_str()
sched,preempt: Move preempt_dynamic to debug.c
sched: Move SCHED_DEBUG sysctl to debugfs
sched: Don't make LATENCYTOP select SCHED_DEBUG
sched: Remove sched_schedstats sysctl out from under SCHED_DEBUG
sched/numa: Allow runtime enabling/disabling of NUMA balance without SCHED_DEBUG
sched: Use cpu_dying() to fix balance_push vs hotplug-rollback
cpumask: Introduce DYING mask
cpumask: Make cpu_{online,possible,present,active}() inline
rseq: Optimise rseq_get_rseq_cs() and clear_rseq_cs()
...

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# ad789f84 15-Apr-2021 Waiman Long <longman@redhat.com>

sched/debug: Fix cgroup_path[] serialization

The handling of sysrq key can be activated by echoing the key to
/proc/sysrq-trigger or via the magic key sequence typed into a terminal
that is connecte

sched/debug: Fix cgroup_path[] serialization

The handling of sysrq key can be activated by echoing the key to
/proc/sysrq-trigger or via the magic key sequence typed into a terminal
that is connected to the system in some way (serial, USB or other mean).
In the former case, the handling is done in a user context. In the
latter case, it is likely to be in an interrupt context.

Currently in print_cpu() of kernel/sched/debug.c, sched_debug_lock is
taken with interrupt disabled for the whole duration of the calls to
print_*_stats() and print_rq() which could last for the quite some time
if the information dump happens on the serial console.

If the system has many cpus and the sched_debug_lock is somehow busy
(e.g. parallel sysrq-t), the system may hit a hard lockup panic
depending on the actually serial console implementation of the
system.

The purpose of sched_debug_lock is to serialize the use of the global
cgroup_path[] buffer in print_cpu(). The rests of the printk calls don't
need serialization from sched_debug_lock.

Calling printk() with interrupt disabled can still be problematic if
multiple instances are running. Allocating a stack buffer of PATH_MAX
bytes is not feasible because of the limited size of the kernel stack.

The solution implemented in this patch is to allow only one caller at a
time to use the full size group_path[], while other simultaneous callers
will have to use shorter stack buffers with the possibility of path
name truncation. A "..." suffix will be printed if truncation may have
happened. The cgroup path name is provided for informational purpose
only, so occasional path name truncation should not be a big problem.

Fixes: efe25c2c7b3a ("sched: Reinstate group names in /proc/sched_debug")
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210415195426.6677-1-longman@redhat.com

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# c006fac5 16-Apr-2021 Paul Turner <pjt@google.com>

sched: Warn on long periods of pending need_resched

CPU scheduler marks need_resched flag to signal a schedule() on a
particular CPU. But, schedule() may not happen immediately in cases
where the cu

sched: Warn on long periods of pending need_resched

CPU scheduler marks need_resched flag to signal a schedule() on a
particular CPU. But, schedule() may not happen immediately in cases
where the current task is executing in the kernel mode (no
preemption state) for extended periods of time.

This patch adds a warn_on if need_resched is pending for more than the
time specified in sysctl resched_latency_warn_ms. If it goes off, it is
likely that there is a missing cond_resched() somewhere. Monitoring is
done via the tick and the accuracy is hence limited to jiffy scale. This
also means that we won't trigger the warning if the tick is disabled.

This feature (LATENCY_WARN) is default disabled.

Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Josh Don <joshdon@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210416212936.390566-1-joshdon@google.com

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# b7f8f259 18-Apr-2021 Tyler Hicks <code@tyhicks.com>

Merge tag 'v5.12-rc7' into ecryptfs/next

Required to pick up idmapped mount changes which changed some function
parameters.


# 9406415f 15-Apr-2021 Peter Zijlstra <peterz@infradead.org>

sched/debug: Rename the sched_debug parameter to sched_verbose

CONFIG_SCHED_DEBUG is the build-time Kconfig knob, the boot param
sched_debug and the /debug/sched/debug_enabled knobs control the
sche

sched/debug: Rename the sched_debug parameter to sched_verbose

CONFIG_SCHED_DEBUG is the build-time Kconfig knob, the boot param
sched_debug and the /debug/sched/debug_enabled knobs control the
sched_debug_enabled variable, but what they really do is make
SCHED_DEBUG more verbose, so rename the lot.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

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# d27e9ae2 25-Mar-2021 Peter Zijlstra <peterz@infradead.org>

sched: Move /proc/sched_debug to debugfs

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Valentin Schneider <vale

sched: Move /proc/sched_debug to debugfs

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210412102001.548833671@infradead.org

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# 3b87f136 25-Mar-2021 Peter Zijlstra <peterz@infradead.org>

sched,debug: Convert sysctl sched_domains to debugfs

Stop polluting sysctl, move to debugfs for SCHED_DEBUG stuff.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar

sched,debug: Convert sysctl sched_domains to debugfs

Stop polluting sysctl, move to debugfs for SCHED_DEBUG stuff.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/YHgB/s4KCBQ1ifdm@hirez.programming.kicks-ass.net

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# 1011dcce 25-Mar-2021 Peter Zijlstra <peterz@infradead.org>

sched,preempt: Move preempt_dynamic to debug.c

Move the #ifdef SCHED_DEBUG bits to kernel/sched/debug.c in order to
collect all the debugfs bits.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infra

sched,preempt: Move preempt_dynamic to debug.c

Move the #ifdef SCHED_DEBUG bits to kernel/sched/debug.c in order to
collect all the debugfs bits.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210412102001.353833279@infradead.org

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# 8a99b683 24-Mar-2021 Peter Zijlstra <peterz@infradead.org>

sched: Move SCHED_DEBUG sysctl to debugfs

Stop polluting sysctl with undocumented knobs that really are debug
only, move them all to /debug/sched/ along with the existing
/debug/sched_* files that a

sched: Move SCHED_DEBUG sysctl to debugfs

Stop polluting sysctl with undocumented knobs that really are debug
only, move them all to /debug/sched/ along with the existing
/debug/sched_* files that already exist.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210412102001.287610138@infradead.org

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# 5acac83b 25-Mar-2021 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge tag 'v5.12-rc4' into next

Sync up with the mainline to bring in newest APIs.


# 3b03706f 18-Mar-2021 Ingo Molnar <mingo@kernel.org>

sched: Fix various typos

Fix ~42 single-word typos in scheduler code comments.

We have accumulated a few fun ones over the years. :-)

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlst

sched: Fix various typos

Fix ~42 single-word typos in scheduler code comments.

We have accumulated a few fun ones over the years. :-)

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: linux-kernel@vger.kernel.org

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# f8bade6c 16-Mar-2021 Maxime Ripard <maxime@cerno.tech>

Merge drm/drm-next into drm-misc-next

Noralf needs some patches in 5.12-rc3, and we've been delaying the 5.12
merge due to the swap issue so it looks like a good time.

Signed-off-by: Maxime Ripard

Merge drm/drm-next into drm-misc-next

Noralf needs some patches in 5.12-rc3, and we've been delaying the 5.12
merge due to the swap issue so it looks like a good time.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

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# b470ebc9 14-Mar-2021 Thomas Gleixner <tglx@linutronix.de>

Merge tag 'irqchip-fixes-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip fixes from Marc Zyngier:

- More compatible strings for the Ingenic

Merge tag 'irqchip-fixes-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip fixes from Marc Zyngier:

- More compatible strings for the Ingenic irqchip (introducing the
JZ4760B SoC)
- Select GENERIC_IRQ_MULTI_HANDLER on the ARM ep93xx platform
- Drop all GENERIC_IRQ_MULTI_HANDLER selections from the irqchip
Kconfig, now relying on the architecture to get it right
- Drop the debugfs_file field from struct irq_domain, now that
debugfs can track things on its own

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# 35bb28ec 11-Mar-2021 Jani Nikula <jani.nikula@intel.com>

Merge drm/drm-next into drm-intel-next

Sync up with upstream.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>


# 4c9f4865 08-Mar-2021 Tony Lindgren <tony@atomide.com>

Merge branch 'fixes-rc2' into fixes


# cdd38c5f 24-Feb-2021 Stefan Schmidt <stefan@datenfreihafen.org>

Merge remote-tracking branch 'net/master'


# cbecf716 22-Feb-2021 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge branch 'next' into for-linus

Prepare input updates for 5.12 merge window.


# 415e915f 22-Feb-2021 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge tag 'v5.11' into next

Merge with mainline to get latest APIs and device tree bindings.


# 72d6e487 22-Feb-2021 Alex Williamson <alex.williamson@redhat.com>

Merge commit '3e10585335b7967326ca7b4118cada0d2d00a2ab' into v5.12/vfio/next

Update to new follow_pte() definition


# 657bd90c 21-Feb-2021 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'sched-core-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
"Core scheduler updates:

- Add CONFIG_PREEMPT_DYNAMIC: this i

Merge tag 'sched-core-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
"Core scheduler updates:

- Add CONFIG_PREEMPT_DYNAMIC: this in its current form adds the
preempt=none/voluntary/full boot options (default: full), to allow
distros to build a PREEMPT kernel but fall back to close to
PREEMPT_VOLUNTARY (or PREEMPT_NONE) runtime scheduling behavior via
a boot time selection.

There's also the /debug/sched_debug switch to do this runtime.

This feature is implemented via runtime patching (a new variant of
static calls).

The scope of the runtime patching can be best reviewed by looking
at the sched_dynamic_update() function in kernel/sched/core.c.

( Note that the dynamic none/voluntary mode isn't 100% identical,
for example preempt-RCU is available in all cases, plus the
preempt count is maintained in all models, which has runtime
overhead even with the code patching. )

The PREEMPT_VOLUNTARY/PREEMPT_NONE models, used by the vast
majority of distributions, are supposed to be unaffected.

- Fix ignored rescheduling after rcu_eqs_enter(). This is a bug that
was found via rcutorture triggering a hang. The bug is that
rcu_idle_enter() may wake up a NOCB kthread, but this happens after
the last generic need_resched() check. Some cpuidle drivers fix it
by chance but many others don't.

In true 2020 fashion the original bug fix has grown into a 5-patch
scheduler/RCU fix series plus another 16 RCU patches to address the
underlying issue of missed preemption events. These are the initial
fixes that should fix current incarnations of the bug.

- Clean up rbtree usage in the scheduler, by providing & using the
following consistent set of rbtree APIs:

partial-order; less() based:
- rb_add(): add a new entry to the rbtree
- rb_add_cached(): like rb_add(), but for a rb_root_cached

total-order; cmp() based:
- rb_find(): find an entry in an rbtree
- rb_find_add(): find an entry, and add if not found

- rb_find_first(): find the first (leftmost) matching entry
- rb_next_match(): continue from rb_find_first()
- rb_for_each(): iterate a sub-tree using the previous two

- Improve the SMP/NUMA load-balancer: scan for an idle sibling in a
single pass. This is a 4-commit series where each commit improves
one aspect of the idle sibling scan logic.

- Improve the cpufreq cooling driver by getting the effective CPU
utilization metrics from the scheduler

- Improve the fair scheduler's active load-balancing logic by
reducing the number of active LB attempts & lengthen the
load-balancing interval. This improves stress-ng mmapfork
performance.

- Fix CFS's estimated utilization (util_est) calculation bug that can
result in too high utilization values

Misc updates & fixes:

- Fix the HRTICK reprogramming & optimization feature

- Fix SCHED_SOFTIRQ raising race & warning in the CPU offlining code

- Reduce dl_add_task_root_domain() overhead

- Fix uprobes refcount bug

- Process pending softirqs in flush_smp_call_function_from_idle()

- Clean up task priority related defines, remove *USER_*PRIO and
USER_PRIO()

- Simplify the sched_init_numa() deduplication sort

- Documentation updates

- Fix EAS bug in update_misfit_status(), which degraded the quality
of energy-balancing

- Smaller cleanups"

* tag 'sched-core-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits)
sched,x86: Allow !PREEMPT_DYNAMIC
entry/kvm: Explicitly flush pending rcuog wakeup before last rescheduling point
entry: Explicitly flush pending rcuog wakeup before last rescheduling point
rcu/nocb: Trigger self-IPI on late deferred wake up before user resume
rcu/nocb: Perform deferred wake up before last idle's need_resched() check
rcu: Pull deferred rcuog wake up to rcu_eqs_enter() callers
sched/features: Distinguish between NORMAL and DEADLINE hrtick
sched/features: Fix hrtick reprogramming
sched/deadline: Reduce rq lock contention in dl_add_task_root_domain()
uprobes: (Re)add missing get_uprobe() in __find_uprobe()
smp: Process pending softirqs in flush_smp_call_function_from_idle()
sched: Harden PREEMPT_DYNAMIC
static_call: Allow module use without exposing static_call_key
sched: Add /debug/sched_preempt
preempt/dynamic: Support dynamic preempt with preempt= boot option
preempt/dynamic: Provide irqentry_exit_cond_resched() static call
preempt/dynamic: Provide preempt_schedule[_notrace]() static calls
preempt/dynamic: Provide cond_resched() and might_resched() static calls
preempt: Introduce CONFIG_PREEMPT_DYNAMIC
static_call: Provide DEFINE_STATIC_CALL_RET0()
...

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# d263dfa7 15-Jan-2021 Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Merge drm/drm-next into drm-intel-gt-next

Backmerging to get a common base for merging topic branches between
drm-intel-next and drm-intel-gt-next.

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@l

Merge drm/drm-next into drm-intel-gt-next

Backmerging to get a common base for merging topic branches between
drm-intel-next and drm-intel-gt-next.

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

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# 65bcf072 30-Oct-2020 Hui Su <sh_def@163.com>

sched: Use task_current() instead of 'rq->curr == p'

Use the task_current() function where appropriate.

No functional change.

Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Peter Zijlstra (

sched: Use task_current() instead of 'rq->curr == p'

Use the task_current() function where appropriate.

No functional change.

Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20201030173223.GA52339@rlk

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