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| author | markj <markj@FreeBSD.org> | 2016-05-18 03:55:54 +0000 |
|---|---|---|
| committer | markj <markj@FreeBSD.org> | 2016-05-18 03:55:54 +0000 |
| commit | e3564c4833de91d62f7f7ede64ceed2471ba19b5 (patch) | |
| tree | d801753c86ba8102960ebe09dbdd06fe1d2687a6 /sys/kern/kern_clock.c | |
| parent | d82dbf711e9365247fa8a848625ca9a761ad62ba (diff) | |
| download | FreeBSD-src-e3564c4833de91d62f7f7ede64ceed2471ba19b5.zip FreeBSD-src-e3564c4833de91d62f7f7ede64ceed2471ba19b5.tar.gz | |
Do not acquire the thread lock in hardclock_cnt() unless needed.
This function only sets thread flags if a SIGPROF or SIGVTALRM timer
has fired, which is almost never the case.
MFC after: 2 weeks
Diffstat (limited to 'sys/kern/kern_clock.c')
| -rw-r--r-- | sys/kern/kern_clock.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/sys/kern/kern_clock.c b/sys/kern/kern_clock.c index 17b85bc..e7a7a99 100644 --- a/sys/kern/kern_clock.c +++ b/sys/kern/kern_clock.c @@ -570,9 +570,11 @@ hardclock_cnt(int cnt, int usermode) flags |= TDF_PROFPEND | TDF_ASTPENDING; PROC_ITIMUNLOCK(p); } - thread_lock(td); - td->td_flags |= flags; - thread_unlock(td); + if (flags != 0) { + thread_lock(td); + td->td_flags |= flags; + thread_unlock(td); + } #ifdef HWPMC_HOOKS if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid))) |
