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authorPeter Zijlstra <peterz@infradead.org>2020-09-08 15:30:31 +0200
committerVasily Gorbik <gor@linux.ibm.com>2020-09-14 10:08:07 +0200
commitca589ea8d1b64938329c016a5c07fc2eea985712 (patch)
treeec197b8d43125473ab21a0a87cc9a1f4fccc6f89
parent856deb866d16e29bd65952e0289066f6078af773 (diff)
s390/idle: fix suspicious RCU usage
After commit eb1f00237aca ("lockdep,trace: Expose tracepoints") the lock tracepoints are visible to lockdep and RCU-lockdep is finding a bunch more RCU violations that were previously hidden. Switch the idle->seqcount over to using raw_write_*() to avoid the lockdep annotation and thus the lock tracepoints. Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
-rw-r--r--arch/s390/kernel/idle.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/s390/kernel/idle.c b/arch/s390/kernel/idle.c
index c73f50649e7e..f7f1e64e0d98 100644
--- a/arch/s390/kernel/idle.c
+++ b/arch/s390/kernel/idle.c
@@ -39,14 +39,13 @@ void enabled_wait(void)
local_irq_restore(flags);
/* Account time spent with enabled wait psw loaded as idle time. */
- /* XXX seqcount has tracepoints that require RCU */
- write_seqcount_begin(&idle->seqcount);
+ raw_write_seqcount_begin(&idle->seqcount);
idle_time = idle->clock_idle_exit - idle->clock_idle_enter;
idle->clock_idle_enter = idle->clock_idle_exit = 0ULL;
idle->idle_time += idle_time;
idle->idle_count++;
account_idle_time(cputime_to_nsecs(idle_time));
- write_seqcount_end(&idle->seqcount);
+ raw_write_seqcount_end(&idle->seqcount);
}
NOKPROBE_SYMBOL(enabled_wait);