From owner-cvs-all@FreeBSD.ORG  Wed Apr 28 14:21:03 2004
Return-Path: <owner-cvs-all@FreeBSD.ORG>
Delivered-To: cvs-all@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id C67A416A4CE; Wed, 28 Apr 2004 14:21:03 -0700 (PDT)
Received: from mail.pcnet.com (mail.pcnet.com [204.213.232.4])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id 6988943D31; Wed, 28 Apr 2004 14:21:03 -0700 (PDT)
	(envelope-from eischen@vigrid.com)
Received: from mail.pcnet.com (mail.pcnet.com [204.213.232.4])
	by mail.pcnet.com (8.12.10/8.12.1) with ESMTP id i3SLL2Qk018391;
	Wed, 28 Apr 2004 17:21:02 -0400 (EDT)
Date: Wed, 28 Apr 2004 17:21:02 -0400 (EDT)
From: Daniel Eischen <eischen@vigrid.com>
X-Sender: eischen@pcnet5.pcnet.com
To: Mike Silbersack <silby@silby.com>
In-Reply-To: <20040428155703.N4795@odysseus.silby.com>
Message-ID: <Pine.GSO.4.10.10404281719380.17691-100000@pcnet5.pcnet.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
cc: cvs-src@FreeBSD.org
cc: src-committers@FreeBSD.org
cc: cvs-all@FreeBSD.org
Subject: Re: cvs commit: src/sys/sys proc.h src/sys/kern kern_thread.c     
 subr_sleepqueue.c
X-BeenThere: cvs-all@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: CVS commit messages for the entire tree <cvs-all.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/cvs-all>,
	<mailto:cvs-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/cvs-all>
List-Post: <mailto:cvs-all@freebsd.org>
List-Help: <mailto:cvs-all-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/cvs-all>,
	<mailto:cvs-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 28 Apr 2004 21:21:04 -0000

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().

-- 
Dan Eischen