lkml.org 
[lkml]   [2023]   [Nov]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[PATCH 0/2] freezer,sched: do not restore saved_state of a thawed task
Date
This series applies couple fixes to commit 8f0eed4a78a8 ("freezer,sched:
Use saved_state to reduce some spurious wakeups") which was found while
testing with legacy cgroup freezer. My original testing was only with
system-wide freezer. We found that thaw_task could be called on a task
which was already frozen. Prior to commit 8f0eed4a78a8 ("freezer,sched:
Use saved_state to reduce some spurious wakeups"), this wasn't an issue
as kernel would try to wake up TASK_FROZEN, which wouldn't match the
thawed task state, and no harm done to task. After commit 8f0eed4a78a8
("freezer,sched: Use saved_state to reduce some spurious wakeups"), it
was possible to overwrite the state of thawed task.

To: Rafael J. Wysocki <rafael@kernel.org>
To: Pavel Machek <pavel@ucw.cz>
To: Ingo Molnar <mingo@kernel.org>
To: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <linux-arm-msm@vger.kernel.org>
Cc: Pavan Kondeti <quic_pkondeti@quicinc.com>
Cc: Aiqun Yu (Maria) <quic_aiquny@quicinc.com>
Cc: <linux-pm@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>

Originally sent to only linux-arm-msm, resending to correct authors.
- Link to v1: https://lore.kernel.org/r/20231120-freezer-state-multiple-thaws-v1-0-a4c453f50745@quicinc.com

---
Elliot Berman (2):
freezer,sched: do not restore saved_state of a thawed task
freezer,sched: clean saved_state when restoring it during thaw

kernel/freezer.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
---
base-commit: 6d7e4782bcf549221b4ccfffec2cf4d1a473f1a3
change-id: 20231108-freezer-state-multiple-thaws-7a3a8d9dadb3

Best regards,
--
Elliot Berman <quic_eberman@quicinc.com>

\
 
 \ /
  Last update: 2023-11-20 18:37    [W:0.082 / U:0.176 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site