From owner-freebsd-hackers Fri Jan 18 22:35:43 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from rwcrmhc53.attbi.com (rwcrmhc53.attbi.com [204.127.198.39]) by hub.freebsd.org (Postfix) with ESMTP id CA55B37B404 for ; Fri, 18 Jan 2002 22:35:37 -0800 (PST) Received: from peter3.wemm.org ([12.232.27.13]) by rwcrmhc53.attbi.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with ESMTP id <20020119063537.TZNL10199.rwcrmhc53.attbi.com@peter3.wemm.org> for ; Sat, 19 Jan 2002 06:35:37 +0000 Received: from overcee.wemm.org (overcee.wemm.org [10.0.0.3]) by peter3.wemm.org (8.11.0/8.11.0) with ESMTP id g0J6Zbs97926 for ; Fri, 18 Jan 2002 22:35:37 -0800 (PST) (envelope-from peter@wemm.org) Received: from wemm.org (localhost [127.0.0.1]) by overcee.wemm.org (Postfix) with ESMTP id EC5EE39EC; Fri, 18 Jan 2002 22:35:36 -0800 (PST) (envelope-from peter@wemm.org) X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 To: Alfred Perlstein Cc: David Malone , Josef Grosch , hackers@FreeBSD.ORG Subject: Re: [nicole@unixgirl.com: What is biord?] In-Reply-To: <20020116151549.O26067@elvis.mu.org> Date: Fri, 18 Jan 2002 22:35:36 -0800 From: Peter Wemm Message-Id: <20020119063536.EC5EE39EC@overcee.wemm.org> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Alfred Perlstein wrote: > * David Malone [020116 14:30] wrote: > > On Wed, Jan 16, 2002 at 02:18:25PM -0800, Josef Grosch wrote: > > > I have a mysql database that seems slow and when looking at it in top it > > > always seems to be in a state of biord > > > What the heck is biord I can't find this anywere > > > > 22:21:gonzo 3% fgrep biord /usr/src/sys/kern/* > > /usr/src/sys/kern/vfs_bio.c: tsleep(&bp->b_xflags, PRIBIO, "bior d", 0); > > /usr/src/sys/kern/vfs_bio.c: tsleep(bp, PRIBIO, "biord", 0); > > > > If you have a look at the code, in vfs_bio.c around these lines, > > you'll see it is to do with waiting for buffers to be read or > > written. Basically it means that the database is spending alot > > of its time waiting for the disk to catch up. > > If you compile mysql using the linuxthreads port instead of freebsd > native threads you _might_ see a performance improvement. > > -Alfred If mysql is blocking on bioread, then it is stalling the entire thread engine when one hits disk IO. Using the linuxthreads port cant help but make it work better / more smoothly.. especially if there are multiple clients. Cheers, -Peter -- Peter Wemm - peter@FreeBSD.org; peter@yahoo-inc.com; peter@netplex.com.au "All of this is for nothing if we don't go to the stars" - JMS/B5 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message