From owner-freebsd-arm@FreeBSD.ORG Wed Jan 30 11:01:45 2013 Return-Path: Delivered-To: freebsd-arm@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id C415A806 for ; Wed, 30 Jan 2013 11:01:45 +0000 (UTC) (envelope-from ronald-freebsd8@klop.yi.org) Received: from smarthost1.greenhost.nl (smarthost1.greenhost.nl [195.190.28.78]) by mx1.freebsd.org (Postfix) with ESMTP id 5FFA3EF1 for ; Wed, 30 Jan 2013 11:01:45 +0000 (UTC) Received: from smtp.greenhost.nl ([213.108.104.138]) by smarthost1.greenhost.nl with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.69) (envelope-from ) id 1U0VQE-0004Dh-Ec for freebsd-arm@freebsd.org; Wed, 30 Jan 2013 12:01:43 +0100 Received: from [81.21.138.17] (helo=ronaldradial.versatec.local) by smtp.greenhost.nl with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.72) (envelope-from ) id 1U0VQE-0001mv-2C for freebsd-arm@freebsd.org; Wed, 30 Jan 2013 12:01:42 +0100 Content-Type: text/plain; charset=us-ascii; format=flowed; delsp=yes To: freebsd-arm@freebsd.org Subject: Re: disk wait mystery References: <20130130001849.7669e033@ivory.lan> <20130130053729.0c9e018f@ivory.lan> Date: Wed, 30 Jan 2013 12:01:42 +0100 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Ronald Klop" Message-ID: In-Reply-To: <20130130053729.0c9e018f@ivory.lan> User-Agent: Opera Mail/12.13 (Win32) X-Virus-Scanned: by clamav at smarthost1.samage.net X-Spam-Level: / X-Spam-Score: 0.8 X-Spam-Status: No, score=0.8 required=5.0 tests=BAYES_50 autolearn=disabled version=3.3.1 X-Scan-Signature: d3d6c6694e059b137bd8e4e2c0542d46 X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Porting FreeBSD to the StrongARM Processor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Jan 2013 11:01:45 -0000 On Wed, 30 Jan 2013 11:37:29 +0100, Brett Wynkoop wrote: > On Wed, 30 Jan 2013 10:39:37 +0100 > "Ronald Klop" wrote: > >> On Wed, 30 Jan 2013 06:18:49 +0100, Brett Wynkoop >> wrote: >> >> > Greeting- >> > >> > Can anyone figure out why a mainly idle bone with only 2 user >> > shells via ssh running would have so much in disk wait? >> > >> > wynkoop@beaglebone:~ % !ps >> > ps ax >> > PID TT STAT TIME COMMAND >> > 0 - DLs 0:00.02 [kernel] >> > 1 - ILs 0:00.20 /sbin/init -- >> > 2 - DL 0:00.00 [xpt_thrd] >> > 3 - DL 0:01.92 [task: mmc/sd card] >> > 4 - DL 0:00.01 [pagedaemon] >> > 5 - DL 0:00.00 [vmdaemon] >> > 6 - DL 0:00.00 [pagezero] >> > 7 - DL 0:00.02 [bufdaemon] >> > 8 - DL 0:00.02 [vnlru] >> > 9 - DL 0:00.10 [syncer] >> > 10 - RL 17:15.90 [idle] >> > 11 - WL 0:07.91 [intr] >> > 12 - DL 0:00.17 [geom] >> > 13 - DL 0:00.21 [yarrow] >> > 14 - DL 0:00.06 [softdepflush] >> > 15 - DL 0:00.15 [schedcpu] >> > 106 - DL 0:00.00 [md0] >> > 410 - Is 0:00.06 dhclient: cpsw0 [priv] (dhclient) >> > 448 - Is 0:00.07 dhclient: cpsw0 (dhclient) >> > 449 - Is 0:00.01 /sbin/devd >> > 634 - Is 0:00.04 /usr/sbin/sshd >> > 638 - Is 0:00.55 /usr/sbin/cron -s >> > 682 - Is 0:00.64 sshd: wynkoop [priv] (sshd) >> > 685 - S 0:00.29 sshd: wynkoop@pts/0 (sshd) >> > 678 u0 Is+ 0:00.19 /usr/libexec/getty std.9600 ttyu0 >> > 686 0 Ss 0:00.74 -csh (csh) >> > 831 0 R+ 0:00.16 ps ax >> > wynkoop@beaglebone:~ % >> > >> > -Brett >> > >> >> Hi, >> >> Maybe I missed a previous email, but you don't provide much >> information for people to think about. >> As a start you might show the 'disk wait' output. >> >> Ronald. >> > > Ronald- > > From the ps man page: > D Marks a process in disk (or other short term, > uninterruptible) wait. > > > Note all the D entries in the above ps output. > > -Brett Aha. My amd64 has the same. I think the ps man page is not very clear. The code src/bin/ps/print.c says this. case SSLEEP: if (tdflags & TDF_SINTR) /* interruptable (long) */ *cp = k->ki_p->ki_slptime >= MAXSLP ? 'I' : 'S'; else *cp = 'D'; break; No mention about disks. Just an uninterruptible sleep (which can be a wait for a disk, but also for other type of alarms/interrupts/locks/etc.). So you have waiting kernel threads/processes. Which is called 'idle'. Ronald.