linux/tools
Tejun Heo e32c260195 sched_ext: Enable the ops breather and eject BPF scheduler on softlockup
On 2 x Intel Sapphire Rapids machines with 224 logical CPUs, a poorly
behaving BPF scheduler can live-lock the system by making multiple CPUs bang
on the same DSQ to the point where soft-lockup detection triggers before
SCX's own watchdog can take action. It also seems possible that the machine
can be live-locked enough to prevent scx_ops_helper, which is an RT task,
from running in a timely manner.

Implement scx_softlockup() which is called when three quarters of
soft-lockup threshold has passed. The function immediately enables the ops
breather and triggers an ops error to initiate ejection of the BPF
scheduler.

The previous and this patch combined enable the kernel to reliably recover
the system from live-lock conditions that can be triggered by a poorly
behaving BPF scheduler on Intel dual socket systems.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
2024-11-08 10:42:22 -10:00
..
accounting
arch RISC-V Patches for the 6.12 Merge Window, Part 1 2024-09-24 10:59:17 -07:00
bootconfig
bpf bpftool: Fix undefined behavior in qsort(NULL, 0, ...) 2024-09-10 11:40:55 -07:00
build perf build: Remove unused feature test target 2024-09-10 17:32:47 -03:00
certs
cgroup
counter
crypto crypto: tools/ccp - Remove unused variable 2024-08-30 18:22:30 +08:00
debugging
firewire
firmware
gpio tools: gpio: rm .*.cmd on make clean 2024-09-02 12:27:35 +02:00
hv hyperv-next for v6.12 2024-09-19 08:15:30 +02:00
iio
include RISC-V Patches for the 6.12 Merge Window, Part 1 2024-09-24 10:59:17 -07:00
kvm/kvm_stat
laptop
leds
lib perf tools improvements and fixes for v6.12: 2024-09-22 09:11:14 -07:00
memory-model tools/memory-model: simple.txt: Fix stale reference to recipes-pairs.txt 2024-09-13 23:56:44 -07:00
mm Many singleton patches - please see the various changelogs for details. 2024-09-21 08:20:50 -07:00
net NFSD 6.12 Release Notes 2024-09-23 12:01:45 -07:00
objtool - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN 2024-07-21 17:15:46 -07:00
pci tools: PCI: Remove unused BILLION macro 2024-09-13 22:37:06 +00:00
pcmcia
perf perf trace: Mark the 'head' arg in the set_robust_list syscall as coming from user space 2024-09-11 17:25:45 -03:00
power linux-cpupower-6.12-rc1-fixes 2024-09-24 12:57:46 -07:00
rcu tools/rcu: Remove RCU Tasks Rude asynchronous APIs from rcu-updaters.sh 2024-07-29 07:39:32 +05:30
sched_ext sched_ext: Enable the ops breather and eject BPF scheduler on softlockup 2024-11-08 10:42:22 -10:00
scripts
sound ASoC: dapm-graph: show path name for non-static routes 2024-08-23 11:03:00 +01:00
spi spi: spidev_fdx: Fix the wrong format specifier 2024-09-04 16:50:33 +01:00
testing sched_ext: Fix enq_last_no_enq_fails selftest 2024-10-25 12:20:29 -10:00
thermal
time
tracing rtla/osnoise: Prevent NULL dereference in error handling 2024-08-09 13:03:15 -04:00
usb
verification tools/verification: Use pkg-config in lib_setup of Makefile.config 2024-07-17 13:14:51 -07:00
virtio tools/virtio: creating pipe assertion in vringh_test 2024-07-04 11:00:31 -04:00
wmi
workqueue
writeback
Makefile