diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-09-22 12:44:11 (GMT) |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2009-09-22 12:05:48 (GMT) |
commit | edaac8e3167501cda336231d00611bf59c164346 (patch) | |
tree | 5ebf22336dccef4fcd601e0a6a2d13ea347ec568 /kernel/sysctl.c | |
parent | 979f693def9084a452846365dfde5dcb28366333 (diff) | |
download | linux-fsl-qoriq-edaac8e3167501cda336231d00611bf59c164346.tar.xz |
ratelimit: Fix/allow use in atomic contexts
I'd like to use printk_ratelimit() in NMI context, but it's not
robust right now due to spinlock usage in lib/ratelimit.c. If an
NMI is unlucky enough to hit just that spot we might lock up trying
to take the spinlock again.
Fix that by using a trylock variant. If we contend on that lock we
can genuinely skip the message because the state is just being
accessed by another CPU (or by this CPU).
( We could use atomics for the suppressed messages field, but
i doubt it matters in practice and it makes the code heavier. )
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sysctl.c')
0 files changed, 0 insertions, 0 deletions