linux/include
Paul Turner c006fac556 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
2021-04-21 13:55:41 +02:00
..
acpi ACPI: scan: Use unique number for instance_no 2021-03-22 17:45:53 +01:00
asm-generic RISC-V Patches for the 5.12 Merge Window 2021-02-26 10:28:35 -08:00
clocksource
crypto
drm drm/ttm: make ttm_bo_unpin more defensive 2021-03-15 16:02:30 +01:00
dt-bindings treewide: change my e-mail address, fix my name 2021-04-09 14:54:23 -07:00
keys
kunit
kvm KVM: arm64: Turn kvm_arm_support_pmu_v3() into a static key 2021-03-06 04:18:40 -05:00
linux sched: Warn on long periods of pending need_resched 2021-04-21 13:55:41 +02:00
math-emu
media media: rc: compile rc-cec.c into rc-core 2021-03-11 11:40:28 +01:00
memory
misc
net ipv6: report errors for iftoken via netlink extack 2021-04-08 13:52:36 -07:00
pcmcia
ras
rdma
scsi scsi: iscsi: Fix race condition between login and sync thread 2021-03-29 21:17:45 -04:00
soc RISC-V Patches for the 5.12 Merge Window 2021-02-26 10:28:35 -08:00
sound ALSA/ASoC/SOF/SoundWire: fix Kconfig issues 2021-03-02 18:30:07 +01:00
target
trace workqueue/tracing: Copy workqueue name to buffer in trace event 2021-03-18 12:57:37 -04:00
uapi Linux 5.12-rc8 2021-04-20 10:13:58 +02:00
vdso
video
xen Xen/gnttab: introduce common INVALID_GRANT_{HANDLE,REF} 2021-03-10 16:39:29 -06:00