Date: Thu, 17 Jul 2003 19:46:30 -0700 (PDT) From: Daniel Eischen <deischen@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/lib/libpthread/thread thr_cond.c thr_mutex.c Message-ID: <200307180246.h6I2kU1s063969@repoman.freebsd.org>
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deischen 2003/07/17 19:46:30 PDT
FreeBSD src repository
Modified files:
lib/libpthread/thread thr_cond.c thr_mutex.c
Log:
Add a preemption point when a mutex or condition variable is
handed-off/signaled to a higher priority thread. Note that when
there are idle KSEs that could run the higher priority thread,
we still add the preemption point because it seems to take the
kernel a while to schedule an idle KSE. The drawbacks are that
threads will be swapped more often between CPUs (KSEs) and
that there will be an extra userland context switch (the idle
KSE is still woken and will probably resume the preempted
thread). We'll revisit this if and when idle CPU/KSE wakeup
times improve.
Inspired by: Petri Helenius <pete@he.iki.fi>
Reviewed by: davidxu
Revision Changes Path
1.47 +8 -0 src/lib/libpthread/thread/thr_cond.c
1.38 +10 -6 src/lib/libpthread/thread/thr_mutex.c
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