cvs commit: src/sys/sys proc.h src/sys/kern kern_thread.c
eischen at vigrid.com
Wed Apr 28 14:21:03 PDT 2004
On Wed, 28 Apr 2004, Mike Silbersack wrote:
> On Wed, 28 Apr 2004, Daniel Eischen wrote:
> > Keep track of threads waiting in kse_release() to avoid a race
> > condition where kse_wakeup() doesn't yet see them in (interruptible)
> > sleep queues. Also add an upcall check to sleepqueue_catch_signals()
> > suggested by jhb.
> > This commit should fix recent mysql hangs.
> > Reviewed by: jhb, davidxu
> > Mysql'd by: Robin P. Blanchard <robin.blanchard at gactr uga edu>
> Thanks, I'm glad to hear that it's fixed.
> Interestingly enough, in addition to stumbling upon this problem with
> mysql, the benchmarking I'm doing for a class project also found a problem
> in the mysql client libraries. For some reasons, when selecting blobs,
> libmysql will get into a loop where it does 4 byte reads. Yes, it will
> read entire 100K objects 4 bytes at a time. I'll post about this to the
> relevant mailing lists next week...
That sounds like a mysql bug. The threads libraries (except for
libc_r) don't do anything with read().
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