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author | Hao Jia <jiahao.os@bytedance.com> | 2023-10-12 17:00:03 +0800 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-11-28 17:19:59 +0000 |
commit | bf5dd542721a4f5145b241cf51e92f3809855d27 (patch) | |
tree | bf812ead171de0cb31a6f26776af1b7077ccc424 /drivers/pmdomain | |
parent | c9400a9dba346177ba1d34ef0981fa8b1ee51001 (diff) | |
download | linux-stable-bf5dd542721a4f5145b241cf51e92f3809855d27.tar.gz linux-stable-bf5dd542721a4f5145b241cf51e92f3809855d27.tar.bz2 linux-stable-bf5dd542721a4f5145b241cf51e92f3809855d27.zip |
sched/core: Fix RQCF_ACT_SKIP leak
commit 5ebde09d91707a4a9bec1e3d213e3c12ffde348f upstream.
Igor Raits and Bagas Sanjaya report a RQCF_ACT_SKIP leak warning.
This warning may be triggered in the following situations:
CPU0 CPU1
__schedule()
*rq->clock_update_flags <<= 1;* unregister_fair_sched_group()
pick_next_task_fair+0x4a/0x410 destroy_cfs_bandwidth()
newidle_balance+0x115/0x3e0 for_each_possible_cpu(i) *i=0*
rq_unpin_lock(this_rq, rf) __cfsb_csd_unthrottle()
raw_spin_rq_unlock(this_rq)
rq_lock(*CPU0_rq*, &rf)
rq_clock_start_loop_update()
rq->clock_update_flags & RQCF_ACT_SKIP <--
raw_spin_rq_lock(this_rq)
The purpose of RQCF_ACT_SKIP is to skip the update rq clock,
but the update is very early in __schedule(), but we clear
RQCF_*_SKIP very late, causing it to span that gap above
and triggering this warning.
In __schedule() we can clear the RQCF_*_SKIP flag immediately
after update_rq_clock() to avoid this RQCF_ACT_SKIP leak warning.
And set rq->clock_update_flags to RQCF_UPDATED to avoid
rq->clock_update_flags < RQCF_ACT_SKIP warning that may be triggered later.
Fixes: ebb83d84e49b ("sched/core: Avoid multiple calling update_rq_clock() in __cfsb_csd_unthrottle()")
Closes: https://lore.kernel.org/all/20230913082424.73252-1-jiahao.os@bytedance.com
Reported-by: Igor Raits <igor.raits@gmail.com>
Reported-by: Bagas Sanjaya <bagasdotme@gmail.com>
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Hao Jia <jiahao.os@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/a5dd536d-041a-2ce9-f4b7-64d8d85c86dc@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/pmdomain')
0 files changed, 0 insertions, 0 deletions