Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755551AbZCDMcy (ORCPT ); Wed, 4 Mar 2009 07:32:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752011AbZCDMcp (ORCPT ); Wed, 4 Mar 2009 07:32:45 -0500 Received: from mx2.redhat.com ([66.187.237.31]:50030 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751524AbZCDMcp (ORCPT ); Wed, 4 Mar 2009 07:32:45 -0500 Message-ID: <49AE74E6.1060008@redhat.com> Date: Wed, 04 Mar 2009 13:32:38 +0100 From: Zdenek Kabelac Organization: Red Hat User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: Wu Fengguang CC: Markus , "linux-kernel@vger.kernel.org" , linux-mm@kvack.org Subject: Re: drop_caches ... References: <200903041057.34072.M4rkusXXL@web.de> <200903041132.04451.M4rkusXXL@web.de> <20090304110558.GA17014@localhost> <200903041229.41482.M4rkusXXL@web.de> <20090304115702.GA17565@localhost> In-Reply-To: <20090304115702.GA17565@localhost> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4307 Lines: 118 Wu Fengguang napsal(a): > On Wed, Mar 04, 2009 at 01:29:40PM +0200, Markus wrote: >>>>> The memory mapped pages won't be dropped in this way. >>>>> "cat /proc/meminfo" will show you the number of mapped pages. >>>> # sync ; echo 3 > /proc/sys/vm/drop_caches ; free -m ; >> cat /proc/meminfo >>>> total used free shared buffers >>>> cached >>>> Mem: 3950 3262 688 0 0 >>>> 359 >>>> -/+ buffers/cache: 2902 1047 >>>> Swap: 5890 1509 4381 >>>> MemTotal: 4045500 kB >>>> MemFree: 705180 kB >>>> Buffers: 508 kB >>>> Cached: 367748 kB >>>> SwapCached: 880744 kB >>>> Active: 1555032 kB >>>> Inactive: 1634868 kB >>>> Active(anon): 1527100 kB >>>> Inactive(anon): 1607328 kB >>>> Active(file): 27932 kB >>>> Inactive(file): 27540 kB >>>> Unevictable: 816 kB >>>> Mlocked: 0 kB >>>> SwapTotal: 6032344 kB >>>> SwapFree: 4486496 kB >>>> Dirty: 0 kB >>>> Writeback: 0 kB >>>> AnonPages: 2378112 kB >>>> Mapped: 52196 kB >>>> Slab: 65640 kB >>>> SReclaimable: 46192 kB >>>> SUnreclaim: 19448 kB >>>> PageTables: 28200 kB >>>> NFS_Unstable: 0 kB >>>> Bounce: 0 kB >>>> WritebackTmp: 0 kB >>>> CommitLimit: 8055092 kB >>>> Committed_AS: 4915636 kB >>>> VmallocTotal: 34359738367 kB >>>> VmallocUsed: 44580 kB >>>> VmallocChunk: 34359677239 kB >>>> DirectMap4k: 3182528 kB >>>> DirectMap2M: 1011712 kB >>>> >>>> The cached reduced to 359 MB (after the dropping). >>>> I dont know where to read the "number of mapped pages". >>>> "Mapped" is about 51 MB. >>> Does your tmpfs store lots of files? >> Dont think so: >> >> # df -h >> Filesystem Size Used Avail Use% Mounted on >> /dev/md6 14G 8.2G 5.6G 60% / >> udev 10M 304K 9.8M 3% /dev >> cachedir 4.0M 100K 4.0M 3% /lib64/splash/cache >> /dev/md4 19G 15G 3.1G 83% /home >> /dev/md3 8.3G 4.5G 3.9G 55% /usr/portage >> shm 2.0G 0 2.0G 0% /dev/shm >> /dev/md1 99M 19M 76M 20% /boot >> >> # mount >> /dev/md6 on / type ext3 (rw,noatime,nodiratime,barrier=0) >> /proc on /proc type proc (rw,noexec,nosuid,noatime,nodiratime) >> sysfs on /sys type sysfs (rw,nosuid,nodev,noexec) >> udev on /dev type tmpfs (rw,nosuid,size=10240k,mode=755) >> devpts on /dev/pts type devpts (rw,nosuid,noexec,gid=5,mode=620) >> cachedir on /lib64/splash/cache type tmpfs (rw,size=4096k,mode=644) >> /dev/md4 on /home type ext3 (rw,noatime,nodiratime,barrier=0) >> /dev/md3 on /usr/portage type ext4 (rw,noatime,nodiratime,barrier=0) >> shm on /dev/shm type tmpfs (rw,noexec,nosuid,nodev) >> usbfs on /proc/bus/usb type usbfs >> (rw,noexec,nosuid,devmode=0664,devgid=85) >> automount(pid6507) on /mnt/.autofs/misc type autofs >> (rw,fd=4,pgrp=6507,minproto=2,maxproto=4) >> automount(pid6521) on /mnt/.autofs/usb type autofs >> (rw,fd=4,pgrp=6521,minproto=2,maxproto=4) >> /dev/md1 on /boot type ext2 (rw,noatime,nodiratime) >> >> I dont know what exactly all that memory is used for. It varies from >> about 300 MB to up to one GB. >> Tell me where to look and I will! > > So you don't have lots of mapped pages(Mapped=51M) or tmpfs files. It's > strange to me that there are so many undroppable cached pages(Cached=359M), > and most of them lie out of the LRU queue(Active+Inactive file=53M)... > > Anyone have better clues on these 'hidden' pages? Maybe try this: cat /proc/`pidof X`/smaps | grep drm | wc -l you will see some growing numbers. Also check cat /proc/dri/0/gem_objects there should be some number # object bytes - which should be close to your missing cached pages. If you are using Intel GEM driver - there is some unlimited caching issue see: http://bugs.freedesktop.org/show_bug.cgi?id=20404 Zdenek -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/