On Oct 4, 2007, at 10:43 AM, Daniel Eischen wrote:
On Thu, 4 Oct 2007, Alfred Perlstein wrote:
* Daniel Eischen <[EMAIL PROTECTED]> [071004 06:05] wrote:
His point about telling us what you're really doing, so we might
off other ways to do it is valid.
We don't know why you are using homegrown user-level spinlocks
instead of pthread mutexes. Priority ceiling mutexes and running
in SCHED_RR or SCHED_FIFO is really what tries to address this
problem, at least from the vague desciption you give. If you
have tried this and they don't work correctly, then one solution
is to fix them ;-)
First of all we're stuck on 6.x, how is threads on this platform?
I don't _think_ there is anything prohibitive of MFC'ing
any libthr bug fixes into 6.x. I would have thought that
you would have tried libthr on 6.x and possibly offered up
"libthr performance sucks for me, and here's why" :-)
Alfred: The Hurricane team uses 1x1 threading on PowerPC
without problems.
The patch below fixes a NULL pointer dereference in the
POSIX priority cases:
diff -up /b/marcelm/freebsd/6.x/src/lib/libthr/thread/thr_mutex.c ./
thr_mutex.c
--- /b/marcelm/freebsd/6.x/src/lib/libthr/thread/thr_mutex.c Sun
Jan 15 21:36:30 2006
+++ ./thr_mutex.c Sun Sep 9 20:58:20 2007
@@ -629,10 +629,14 @@ mutex_lock_common(struct pthread *curthr
/* Unlock the mutex structure: */
THR_LOCK_RELEASE(curthread, &(*m)-
>m_lock);
- clock_gettime(CLOCK_REALTIME, &ts);
- TIMESPEC_SUB(&ts2, abstime, &ts);
- ret = _thr_umtx_wait(&curthread-
>cycle, cycle,
- &ts2);
+ if (abstime != NULL) {
+ clock_gettime(CLOCK_REALTIME,
&ts);
+ TIMESPEC_SUB(&ts2, abstime,
&ts);
+ ret = _thr_umtx_wait
(&curthread->cycle,
+ cycle, &ts2);
+ } else
+ ret = _thr_umtx_wait
(&curthread->cycle,
+ cycle, NULL);
if (ret == EINTR)
ret = 0;
@@ -712,10 +716,14 @@ mutex_lock_common(struct pthread *curthr
/* Unlock the mutex structure: */
THR_LOCK_RELEASE(curthread, &(*m)-
>m_lock);
- clock_gettime(CLOCK_REALTIME, &ts);
- TIMESPEC_SUB(&ts2, abstime, &ts);
- ret = _thr_umtx_wait(&curthread-
>cycle, cycle,
- &ts2);
+ if (abstime != NULL) {
+ clock_gettime(CLOCK_REALTIME,
&ts);
+ TIMESPEC_SUB(&ts2, abstime,
&ts);
+ ret = _thr_umtx_wait
(&curthread->cycle,
+ cycle, &ts2);
+ } else
+ ret = _thr_umtx_wait
(&curthread->cycle,
+ cycle, NULL);
if (ret == EINTR)
ret = 0;
I don't know if anyone other than possibly David Xu have
tested SCHED_RR or SCHED_FIFO and priority ceiling mutexes,
so they may not work as they're suppose to.
We use it successfully with the above patch.
FYI,
--
Marcel Moolenaar
[EMAIL PROTECTED]
_______________________________________________
[email protected] mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-hackers
To unsubscribe, send any mail to "[EMAIL PROTECTED]"
