From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 3EBFC6B00A8 for ; Wed, 4 Mar 2009 08:47:54 -0500 (EST) From: Markus Subject: Re: drop_caches ... Date: Wed, 4 Mar 2009 14:47:45 +0100 References: <200903041057.34072.M4rkusXXL@web.de> <20090304115702.GA17565@localhost> <49AE74E6.1060008@redhat.com> In-Reply-To: <49AE74E6.1060008@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200903041447.49534.M4rkusXXL@web.de> Sender: owner-linux-mm@kvack.org To: linux-kernel@vger.kernel.org Cc: Zdenek Kabelac , Wu Fengguang , linux-mm@kvack.org List-ID: > >>>>> 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 > # cat /proc/`pidof X`/smaps | grep drm | wc -l 0 # cat /proc/dri/0/gem_objects cat: /proc/dri/0/gem_objects: No such file or directory I use Xorg 1.3 with an nvidia gpu. Dont know if I use a "Intel GEM driver". Btw I am running a 2.6.28.2. Thanks. Markus -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org