From: Markus <M4rkusXXL@web.de>
To: linux-kernel@vger.kernel.org
Subject: Re: drop_caches ...
Date: Wed, 4 Mar 2009 12:29:40 +0100
User-Agent: KMail/1.9.10
Cc: Wu Fengguang <fengguang.wu@intel.com>
References: <200903041057.34072.M4rkusXXL@web.de> <200903041132.04451.M4rkusXXL@web.de> <20090304110558.GA17014@localhost>
In-Reply-To: <20090304110558.GA17014@localhost>
MIME-Version: 1.0
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200903041229.41482.M4rkusXXL@web.de>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 3437
Lines: 93

> > > 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!

Thanks!

Markus
--
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/