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8dafa9d0eb
linux/kernel/sched
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Peter Zijlstra 8dafa9d0eb sched/eevdf: Fix min_deadline heap integrity 
Marek and Biju reported instances of:

  "EEVDF scheduling fail, picking leftmost"

which Mike correlated with cgroup scheduling and the min_deadline heap
getting corrupted; some trace output confirms:

> And yeah, min_deadline is hosed somehow:
>
>    validate_cfs_rq: --- /
>    __print_se: ffff88845cf48080 w: 1024 ve: -58857638 lag: 870381 vd: -55861854 vmd: -66302085 E (11372/tr)
>    __print_se:   ffff88810d165800 w: 25 ve: -80323686 lag: 22336429 vd: -41496434 vmd: -66302085 E (-1//autogroup-31)
>    __print_se:   ffff888108379000 w: 25 ve: 0 lag: -57987257 vd: 114632828 vmd: 114632828 N (-1//autogroup-33)
>    validate_cfs_rq: min_deadline: -55861854 avg_vruntime: -62278313462 / 1074 = -57987256

Turns out that reweight_entity(), which tries really hard to be fast,
does not do the normal dequeue+update+enqueue pattern but *does* scale
the deadline.

However, it then fails to propagate the updated deadline value up the
heap.

Fixes: 147f3efaa2 ("sched/fair: Implement an EEVDF-like scheduling policy")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reported-by: Biju Das <biju.das.jz@bp.renesas.com>
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Biju Das <biju.das.jz@bp.renesas.com>
Tested-by: Mike Galbraith <efault@gmx.de>
Link: https://lkml.kernel.org/r/20231006192445.GE743@noisy.programming.kicks-ass.net
2023-10-09 09:48:32 +02:00
..
autogroup.c
autogroup.h
build_policy.c
build_utility.c
clock.c Locking changes for v6.5: 2023-06-27 14:14:30 -07:00
completion.c sched: add a few helpers to wake up tasks on the current cpu 2023-07-17 16:08:08 -07:00
core_sched.c sched: Rename task_running() to task_on_cpu() 2022-09-07 21:53:47 +02:00
core.c kernel/sched: Modify initial boot task idle setup 2023-09-19 10:48:04 +02:00
cpuacct.c
cpudeadline.c
cpudeadline.h
cpufreq_schedutil.c cpufreq: schedutil: Update next_freq when cpufreq_limits change 2023-10-05 22:09:50 +02:00
cpufreq.c
cpupri.c sched/rt: Fix live lock between select_fallback_rq() and RT push 2023-09-28 22:58:13 +02:00
cpupri.h
cputime.c cputime: remove cputime_to_nsecs fallback 2022-12-27 12:52:17 +01:00
deadline.c cgroup: Changes for v6.5 2023-06-27 16:54:21 -07:00
debug.c sched/debug: Rename sysctl_sched_min_granularity to sysctl_sched_base_slice 2023-07-19 09:43:59 +02:00
fair.c sched/eevdf: Fix min_deadline heap integrity 2023-10-09 09:48:32 +02:00
features.h sched/eevdf: Curb wakeup-preemption 2023-08-17 17:07:07 +02:00
idle.c kernel/sched: Modify initial boot task idle setup 2023-09-19 10:48:04 +02:00
isolation.c
loadavg.c
Makefile
membarrier.c sched/membarrier: Introduce MEMBARRIER_CMD_GET_REGISTRATIONS 2023-01-07 11:29:29 +01:00
pelt.c
pelt.h
psi.c Linux 6.5-rc2 2023-07-19 09:43:25 +02:00
rt.c sched/rt: sysctl_sched_rr_timeslice show default timeslice after reset 2023-08-14 17:01:23 +02:00
sched-pelt.h
sched.h Misc x86 cleanups. 2023-08-28 17:05:58 -07:00
smp.h sched, smp: Trace smp callback causing an IPI 2023-03-24 11:01:29 +01:00
stats.c
stats.h sched/psi: Use task->psi_flags to clear in CPU migration 2022-10-30 10:12:15 +01:00
stop_task.c
swait.c sched: add a few helpers to wake up tasks on the current cpu 2023-07-17 16:08:08 -07:00
topology.c sched/topology: Align group flags when removing degenerate domain 2023-07-26 12:28:51 +02:00
wait_bit.c
wait.c sched: add a few helpers to wake up tasks on the current cpu 2023-07-17 16:08:08 -07:00