This is a note to let you know that I've just added the patch titled
sched: Fix DEBUG && !SCHEDSTATS warn
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sched-fix-debug-schedstats-warn.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 769fdf83df57b373660343ef4270b3ada91ef434 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Wed, 6 Oct 2021 10:12:05 +0200
Subject: sched: Fix DEBUG && !SCHEDSTATS warn
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
commit 769fdf83df57b373660343ef4270b3ada91ef434 upstream.
When !SCHEDSTATS schedstat_enabled() is an unconditional 0 and the
whole block doesn't exist, however GCC figures the scoped variable
'stats' is unused and complains about it.
Upgrade the warning from -Wunused-variable to -Wunused-but-set-variable
by writing it in two statements. This fixes the build because the new
warning is in W=1.
Given that whole if(0) {} thing, I don't feel motivated to change
things overly much and quite strongly feel this is the compiler being
daft.
Fixes: cb3e971c435d ("sched: Make struct sched_statistics independent of fair sched class")
Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/sched/debug.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -462,7 +462,8 @@ static void print_cfs_group_stats(struct
PN(se->sum_exec_runtime);
if (schedstat_enabled()) {
- struct sched_statistics *stats = __schedstats_from_se(se);
+ struct sched_statistics *stats;
+ stats = __schedstats_from_se(se);
PN_SCHEDSTAT(wait_start);
PN_SCHEDSTAT(sleep_start);
Patches currently in stable-queue which might be from peterz@xxxxxxxxxxxxx are
queue-5.15/sched-rt-fix-bad-task-migration-for-rt-tasks.patch
queue-5.15/sched-make-struct-sched_statistics-independent-of-fa.patch
queue-5.15/sched-fair-use-__schedstat_set-in-set_next_entity.patch
queue-5.15/sched-fair-fix-inaccurate-tally-of-ttwu_move_affine.patch
queue-5.15/perf-core-fix-hardlockup-failure-caused-by-perf-thro.patch
queue-5.15/revert-objtool-support-addition-to-set-cfa-base.patch
queue-5.15/sched-fix-debug-schedstats-warn.patch
