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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-03-24 19:07:15 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-03-24 19:07:15 +0100 |
| commit | 92896bd9fd75b1c993b92874d339a8088bb75560 (patch) | |
| tree | 2bd8bc5a8c8ee10a4b1fd62804281d2b486067f0 /kernel/time | |
| parent | Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rol... (diff) | |
| download | linux-92896bd9fd75b1c993b92874d339a8088bb75560.tar.xz linux-92896bd9fd75b1c993b92874d339a8088bb75560.zip | |
Don't 'printk()' while holding xtime lock for writing
The printk() can deadlock because it can wake up klogd(), and
task enqueueing will try to read the time in order to set a hrtimer.
Reported-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Debugged-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/timekeeping.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 671af612b768..a3fa587c350c 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -191,8 +191,12 @@ static void change_clocksource(void) tick_clock_notify(); + /* + * We're holding xtime lock and waking up klogd would deadlock + * us on enqueue. So no printing! printk(KERN_INFO "Time: %s clocksource has been installed.\n", clock->name); + */ } #else static inline void change_clocksource(void) { } |