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authorHeiko Carstens <heiko.carstens@de.ibm.com>2008-07-11 11:09:22 +0200
committerIngo Molnar <mingo@elte.hu>2008-07-11 11:17:04 +0200
commit857f3fd7a496ddf4329345af65a4a2b16dd25fe8 (patch)
tree7bd1b0de6e82363beba60097529b72ac7de923f5 /kernel/time
parent7a14ce1d8c1d3a6118d406e64eaf9aa70375e085 (diff)
downloadop-kernel-dev-857f3fd7a496ddf4329345af65a4a2b16dd25fe8.zip
op-kernel-dev-857f3fd7a496ddf4329345af65a4a2b16dd25fe8.tar.gz
nohz: don't stop idle tick if softirqs are pending.
In case a cpu goes idle but softirqs are pending only an error message is printed to the console. It may take a very long time until the pending softirqs will finally be executed. Worst case would be a hanging system. With this patch the timer tick just continues and the softirqs will be executed after the next interrupt. Still a delay but better than a hanging system. Currently we have at least two device drivers on s390 which under certain circumstances schedule a tasklet from process context. This is a reason why we can end up with pending softirqs when going idle. Fixing these drivers seems to be non-trivial. However there is no question that the drivers should be fixed. This patch shouldn't be considered as a bug fix. It just is intended to keep a system running even if device drivers are buggy. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Glauber <jan.glauber@de.ibm.com> Cc: Stefan Weinhuber <wein@de.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/time')
-rw-r--r--kernel/time/tick-sched.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index cb75394..86baa4f 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -235,6 +235,7 @@ void tick_nohz_stop_sched_tick(void)
local_softirq_pending());
ratelimit++;
}
+ goto end;
}
ts->idle_calls++;
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