From owner-freebsd-stable@FreeBSD.ORG Wed Aug 20 16:09:27 2014 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 4FC8EA5B for ; Wed, 20 Aug 2014 16:09:27 +0000 (UTC) Received: from pp2.rice.edu (proofpoint2.mail.rice.edu [128.42.201.101]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 0C4D7322B for ; Wed, 20 Aug 2014 16:09:26 +0000 (UTC) Received: from pps.filterd (pp2.rice.edu [127.0.0.1]) by pp2.rice.edu (8.14.5/8.14.5) with SMTP id s7KFvVt4025184; Wed, 20 Aug 2014 11:09:19 -0500 Received: from mh2.mail.rice.edu (mh2.mail.rice.edu [128.42.201.21]) by pp2.rice.edu with ESMTP id 1nve1pgax2-1; Wed, 20 Aug 2014 11:09:19 -0500 X-Virus-Scanned: by amavis-2.7.0 at mh2.mail.rice.edu, auth channel Received: from 108-254-203-201.lightspeed.hstntx.sbcglobal.net (108-254-203-201.lightspeed.hstntx.sbcglobal.net [108.254.203.201]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (No client certificate requested) (Authenticated sender: alc) by mh2.mail.rice.edu (Postfix) with ESMTPSA id 06F5B500128; Wed, 20 Aug 2014 11:09:18 -0500 (CDT) Message-ID: <53F4C82E.5000900@rice.edu> Date: Wed, 20 Aug 2014 11:09:18 -0500 From: Alan Cox User-Agent: Mozilla/5.0 (X11; FreeBSD i386; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: "Polyack, Steve" , "freebsd-stable@freebsd.org" Subject: Re: vmdaemon CPU usage and poor performance in 10.0-RELEASE References: <4D557EC7CC2A544AA7C1A3B9CBA2B36726098846B4@exchange03.epbs.com> <20140813152522.GI9400@home.opsec.eu> <4D557EC7CC2A544AA7C1A3B9CBA2B36726098847AF@exchange03.epbs.com> <4D557EC7CC2A544AA7C1A3B9CBA2B3672609BBA3C4@exchange03.epbs.com> <53F24E5B.1010809@rice.edu> <4D557EC7CC2A544AA7C1A3B9CBA2B3672609BBA64F@exchange03.epbs.com> <53F2790C.20703@rice.edu> <4D557EC7CC2A544AA7C1A3B9CBA2B3672609CF28E5@exchange03.epbs.com> <4D557EC7CC2A544AA7C1A3B9CBA2B3672609CF2F8F@exchange03.epbs.com> <4D557EC7CC2A544AA7C1A3B9CBA2B3672609CF31F0@exchange03.epbs.com> <53F4C4C2.1030109@rice.edu> <4D557EC7CC2A544AA7C1A3B9CBA2B3672609CF335D@exchange03.epbs.com> In-Reply-To: <4D557EC7CC2A544AA7C1A3B9CBA2B3672609CF335D@exchange03.epbs.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 kscore.is_bulkscore=2.43328298512036e-05 kscore.compositescore=0 circleOfTrustscore=0 compositescore=0.353842562264287 urlsuspect_oldscore=0.353842562264287 suspectscore=11 recipient_domain_to_sender_totalscore=0 phishscore=0 bulkscore=0 kscore.is_spamscore=0 recipient_to_sender_totalscore=0 recipient_domain_to_sender_domain_totalscore=0 rbsscore=0.353842562264287 spamscore=0 recipient_to_sender_domain_totalscore=0 urlsuspectscore=0.9 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1402240000 definitions=main-1408200165 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 Aug 2014 16:09:27 -0000 On 08/20/2014 10:56, Polyack, Steve wrote: >> -----Original Message----- >> From: Alan Cox [mailto:alc@rice.edu] >> Sent: Wednesday, August 20, 2014 11:55 AM >> To: Polyack, Steve; freebsd-stable@freebsd.org >> Subject: Re: vmdaemon CPU usage and poor performance in 10.0-RELEASE >> >> On 08/20/2014 09:55, Polyack, Steve wrote: >>>> -----Original Message----- >>>> From: Polyack, Steve >>>> Sent: Wednesday, August 20, 2014 9:14 AM >>>> To: Polyack, Steve; Alan Cox; freebsd-stable@freebsd.org >>>> Subject: RE: vmdaemon CPU usage and poor performance in 10.0-RELEASE >>>> >>>> >>>>> -----Original Message----- >>>>> From: owner-freebsd-stable@freebsd.org [mailto:owner-freebsd- >>>>> stable@freebsd.org] On Behalf Of Polyack, Steve >>>>> Sent: Tuesday, August 19, 2014 12:37 PM >>>>> To: Alan Cox; freebsd-stable@freebsd.org >>>>> Subject: RE: vmdaemon CPU usage and poor performance in 10.0- >> RELEASE >>>>>> -----Original Message----- >>>>>> From: owner-freebsd-stable@freebsd.org [mailto:owner-freebsd- >>>>>> stable@freebsd.org] On Behalf Of Alan Cox >>>>>> Sent: Monday, August 18, 2014 6:07 PM >>>>>> To: freebsd-stable@freebsd.org >>>>>> Subject: Re: vmdaemon CPU usage and poor performance in 10.0- >>>> RELEASE >>>>>> On 08/18/2014 16:29, Polyack, Steve wrote: >>>>>>>> -----Original Message----- >>>>>>>> From: owner-freebsd-stable@freebsd.org [mailto:owner-freebsd- >>>>>>>> stable@freebsd.org] On Behalf Of Alan Cox >>>>>>>> Sent: Monday, August 18, 2014 3:05 PM >>>>>>>> To: freebsd-stable@freebsd.org >>>>>>>> Subject: Re: vmdaemon CPU usage and poor performance in 10.0- >>>>> RELEASE >>>>>>>> On 08/18/2014 13:42, Polyack, Steve wrote: >>>>>>>>> Excuse my poorly formatted reply at the moment, but this seems to >>>>>> have >>>>>>>> fixed our problems. I'm going to update the bug report with a note. >>>>>>>>> Thanks Alan! >>>>>>>> You're welcome. And, thanks for letting me know of the outcome. >>>>>>>> >>>>>>> Actually, I may have spoken too soon, as it looks like we're seeing >>>>>> vmdaemon tying up the system again: >>>>>>> root 6 100.0 0.0 0 16 - DL Wed04PM 4:37.95 >>>>> [vmdaemon] >>>>>>> Is there anything I can check to help narrow down what may be the >>>>>> problem? KTrace/truss on the "process" doesn't give any information, I >>>>>> suppose because it's actually a kernel thread. >>>>>> >>>>>> Can you provide the full output of top? Is there anything unusual >> about >>>>>> the hardware or software configuration? >>>>> This may have just been a fluke (maybe NFS caching the old >> vm_pageout.c >>>>> during the first source build). We've rebuilt and are monitoring it now. >>>>> >>>>> The hardware consists of a few Dell PowerEdge R720xd servers with >> 256GB >>>>> of RAM and array of SSDs (no ZFS). 64GB is dedicated to postgres >>>>> shared_buffers right now. FreeBSD 10, PostgreSQL 9.3, Slony-I v2.2.2, >> and >>>>> redis-2.8.11 are all in use here. I can't say that anything is unusual about >>>> the >>>>> configuration. >>>>> >>>> We are still seeing the issue. It seems to manifest once the "Free" >> memory >>>> gets under 10GB (of 256GB on the system), even though ~200GB of this is >>>> classified as Inactive. For us, this was about 7 hours of database activity >>>> (initial replication w/ slony). Right now vmdaemon is consuming 100% >> CPU >>>> and shows 671:34 CPU time when it showed 0:00 up until the problem >>>> manifested. The full top output (that fits on my screen) is below: >>>> >>>> last pid: 62309; load averages: 4.05, 4.24, 4.10 >>>> up 0+22:34:31 09:08:43 >>>> 159 processes: 8 running, 145 sleeping, 1 waiting, 5 lock >>>> CPU: 14.5% user, 0.0% nice, 4.9% system, 0.0% interrupt, 80.5% idle >>>> Mem: 26G Active, 216G Inact, 4122M Wired, 1178M Cache, 1632M Buf, >> 2136M >>>> Free >>>> Swap: 32G Total, 32G Free >>>> >>>> PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU >>>> COMMAND >>>> 11 root 32 155 ki31 0K 512K CPU31 31 669.6H 2934.23% idle >>>> 6 root 1 -16 - 0K 16K CPU19 19 678:57 100.00% vmdaemon >>>> 1963 pgsql 1 45 0 67538M 208M CPU0 0 121:46 17.38% postgres >>>> 2037 pgsql 1 77 0 67536M 2200K *vm ob 14 6:24 15.97% postgres >>>> 1864 pgsql 1 31 0 67536M 1290M semwai 4 174:41 15.19% >> postgres >>>> 1996 pgsql 1 38 0 67538M 202M semwai 16 120:27 15.09% >> postgres >>>> 1959 pgsql 1 39 0 67538M 204M CPU27 27 117:30 15.09% postgres >>>> 1849 pgsql 1 32 0 67536M 1272M semwai 23 126:22 13.96% >> postgres >>>> 1997 pgsql 1 31 0 67538M 206M CPU30 30 122:26 11.77% postgres >>>> 2002 pgsql 1 34 0 67538M 182M sbwait 11 55:20 11.28% postgres >>>> 1961 pgsql 1 32 0 67538M 206M CPU12 12 121:47 10.99% postgres >>>> 1964 pgsql 1 30 0 67538M 206M semwai 28 122:08 9.86% postgres >>>> 1962 pgsql 1 29 0 67538M 1286M sbwait 2 45:49 7.18% postgres >>>> 1752 root 1 22 0 78356K 8688K CPU2 2 175:46 6.88% snmpd >>>> 1965 pgsql 1 25 0 67538M 207M semwai 9 120:55 6.59% postgres >>>> 1960 pgsql 1 23 0 67538M 177M semwai 6 52:42 4.88% postgres >>>> 1863 pgsql 1 25 0 67542M 388M semwai 25 9:12 2.20% postgres >>>> 1859 pgsql 1 22 0 67538M 1453M *vm ob 20 6:13 2.10% postgres >>>> 1860 pgsql 1 22 0 67538M 1454M sbwait 8 6:08 1.95% postgres >>>> 1848 pgsql 1 21 0 67586M 66676M *vm ob 30 517:07 1.66% >> postgres >>>> 1856 pgsql 1 22 0 67538M 290M *vm ob 15 5:39 1.66% postgres >>>> 1846 pgsql 1 21 0 67538M 163M sbwait 15 5:46 1.46% postgres >>>> 1853 pgsql 1 21 0 67538M 110M sbwait 30 8:54 1.17% postgres >>>> 1989 pgsql 1 23 0 67536M 5180K sbwait 18 1:41 0.98% postgres >>>> 5 root 1 -16 - 0K 16K psleep 6 9:33 0.78% pagedaemon >>>> 1854 pgsql 1 20 0 67538M 338M sbwait 22 5:38 0.78% postgres >>>> 1861 pgsql 1 20 0 67538M 286M sbwait 15 6:13 0.68% postgres >>>> 1857 pgsql 1 20 0 67538M 1454M semwai 10 6:19 0.49% postgres >>>> 1999 pgsql 1 36 0 67538M 156M *vm ob 28 120:56 0.39% postgres >>>> 1851 pgsql 1 20 0 67538M 136M sbwait 22 5:48 0.39% postgres >>>> 1975 pgsql 1 20 0 67536M 5688K sbwait 25 1:40 0.29% postgres >>>> 1858 pgsql 1 20 0 67538M 417M sbwait 3 5:55 0.20% postgres >>>> 2031 pgsql 1 20 0 67536M 5664K sbwait 5 3:26 0.10% postgres >>>> 1834 root 12 20 0 71892K 12848K select 20 34:05 0.00% slon >>>> 12 root 78 -76 - 0K 1248K WAIT 0 25:47 0.00% intr >>>> 2041 pgsql 1 20 0 67536M 5932K sbwait 14 12:50 0.00% postgres >>>> 2039 pgsql 1 20 0 67536M 5960K sbwait 17 9:59 0.00% postgres >>>> 2038 pgsql 1 20 0 67536M 5956K sbwait 6 8:21 0.00% postgres >>>> 2040 pgsql 1 20 0 67536M 5996K sbwait 7 8:20 0.00% postgres >>>> 2032 pgsql 1 20 0 67536M 5800K sbwait 22 7:03 0.00% postgres >>>> 2036 pgsql 1 20 0 67536M 5748K sbwait 23 6:38 0.00% postgres >>>> 1812 pgsql 1 20 0 67538M 59185M select 1 5:46 0.00% postgres >>>> 2005 pgsql 1 20 0 67536M 5788K sbwait 23 5:14 0.00% postgres >>>> 2035 pgsql 1 20 0 67536M 4892K sbwait 18 4:52 0.00% >>>> 1852 pgsql 1 21 0 67536M 1230M semwai 7 4:47 0.00% postgres >>>> 13 root 3 -8 - 0K 48K - 28 4:46 0.00% geom >>>> >>>> >>> Another thing I've noticed is that this sysctl vm.stats counter is increasing >> fairly rapidly: >>> # sysctl vm.stats.vm.v_pdpages && sleep 1 && sysctl >> vm.stats.vm.v_pdpages >>> vm.stats.vm.v_pdpages: 3455264541 >>> vm.stats.vm.v_pdpages: 3662158383 >> I'm not sure what that tells us, because both the page daemon and the vm >> ("swap") daemon increment this counter. >> >>> Also, to demonstrate what kind of problems this seems to cause: >>> # time sleep 1 >>> >>> real 0m18.288s >>> user 0m0.001s >>> sys 0m0.004s >> If you change the sysctl vm.swap_enabled to 0, how does your system >> behave? >> > Setting vm.swap_enabled to 0 made the problem clear up almost instantly. vmdaemon is back to 0.00% CPU usage and the system is responsive once again. > > I doubt that you need whole process swapping. The page daemon is probably sufficient. See how things go for a few days and let me know. There is still a bug here that needs diagnosing and fixing. So, I will likely send you a debugging patch in the near future, and ask you to reenable swapping under that patch.