Cache issue with 10.04

[Jaakan Shorter]

My current HTPC use to always be around 50% ram used since I built it almost 2 years ago and now it hovering around 95% to 99%. I really notice this on my laptop before I upgraded my ram from 1G to 4Gb. Something has changed with 10.04.

there seems to be an issue system wide with caching

mythfrontend for my only uses 20% of my ram
mythbackend 2.4%
mysql 1.5%
Xorg 4%

my laptop
Code:

             total used free shared buffers cached
Mem: 3928280 1838056 2090224 0 119328 1004872
-/+ buffers/cache: 713856 3214424
Swap: 2000084 0 2000084

my Mythtv HTPC
Code:

             total used free shared buffers cached
Mem: 2056768 2039956 16812 0 64708 679500
-/+ buffers/cache: 1295748 761020
Swap: 2000052 0 2000052

look at how cache is used in 9.10
upgrade to 10.04
look at how cache is used

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: linux-image-2.6.32-19-generic 2.6.32-19.28
Regression: Yes
Reproducible: Yes
ProcVersionSignature: Ubuntu 2.6.32-19.28-generic 2.6.32.10+drm33.1
Uname: Linux 2.6.32-19-generic x86_64
NonfreeKernelModules: wl
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.21.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: SB [HDA ATI SB], device 0: STAC92xx Analog [STAC92xx Analog]
   Subdevices: 0/1
   Subdevice #0: subdevice #0
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: SB [HDA ATI SB], device 0: STAC92xx Analog [STAC92xx Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: jaakan 1664 F.... pulseaudio
 /dev/snd/pcmC0D0p: jaakan 1664 F...m pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'SB'/'HDA ATI SB at 0xc0000000 irq 16'
   Mixer name : 'SigmaTel STAC9200'
   Components : 'HDA:14f12c06,14f1000f,00100000 HDA:83847690,102801f5,00102201'
   Controls : 6
   Simple ctrls : 4
Date: Fri Apr 9 08:20:35 2010
HibernationDevice: RESUME=UUID=6afe3826-956f-430e-bd9d-c10c5ce210cc
MachineType: Dell Inc. Vostro 1000
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-19-generic root=UUID=99d8c97a-ec1a-4c47-9329-db8d98367aaa ro quiet splash
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
RelatedPackageVersions: linux-firmware 1.33
RfKill:

SourcePackage: linux
WifiSyslog:

dmi.bios.date: 12/07/2007
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 2.6.3
dmi.board.name: 0WY383
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: Not Specified
dmi.modalias: dmi:bvnDellInc.:bvr2.6.3:bd12/07/2007:svnDellInc.:pnVostro1000:pvrNotSpecified:rvnDellInc.:rn0WY383:rvr:cvnDellInc.:ct8:cvrNotSpecified:
dmi.product.name: Vostro 1000
dmi.product.version: Not Specified
dmi.sys.vendor: Dell Inc.

[Jaakan Shorter (jaakanshorter)]

I added 4 Gb of ram to my MythTV box ( 6Gb total now ) with in one hour most of my ram is used up by cache.
On boot just under 2 Gb is used and after one hour the rest is all cache

commercial flagging and recording playback are when I see how much is used go up, via phpsysinfo and htop

on my laptop just using firefox i see cache go up and never down.
Don't have this issue with chome or opera

this was not an issue on 9.10

ureadahead might be the problem or the kernal or something related

[Jeremy Foshee (jeremyfoshee)]

Hi Jaakan,

If you could also please test the latest upstream kernel available that would be great. It will allow additional upstream developers to examine the issue. Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text. Please let us know your results.

Thanks in advance.

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[Jaakan Shorter (jaakanshorter)]

linux-image-2.6.34-020634rc5-generic_2.6.34-020634rc5_amd64.deb

after boot ( no wifi )

jaakan@jms1000:~$ free
             total used free shared buffers cached
Mem: 3928112 530956 3397156 0 59396 150664
-/+ buffers/cache: 320896 3607216
Swap: 2000088 0 2000088

After openning gedit , firefox, opera, Chromium, rhythmbox , and started playing a 125Mb mpg in totem

jaakan@jms1000:~$ free
             total used free shared buffers cached
Mem: 3928112 1219900 2708212 0 75612 484304
-/+ buffers/cache: 659984 3268128
Swap: 2000088 0 2000088

I closed all but gedit

jaakan@jms1000:~$ free
             total used free shared buffers cached
Mem: 3928112 1003084 2925028 0 76724 481144
-/+ buffers/cache: 445216 3482896
Swap: 2000088 0 2000088

just opened firefox , gedit still open

jaakan@jms1000:~$ free
             total used free shared buffers cached
Mem: 3928112 1050888 2877224 0 77016 481704
-/+ buffers/cache: 492168 3435944
Swap: 2000088 0 2000088

closed firefox , gedit still open

jaakan@jms1000:~$ free
             total used free shared buffers cached
Mem: 3928112 1004624 2923488 0 77048 481244
-/+ buffers/cache: 446332 3481780
Swap: 2000088 0 2000088

after a few minutes

jaakan@jms1000:~$ free
             total used free shared buffers cached
Mem: 3928112 1006748 2921364 0 77208 481260
-/+ buffers/cache: 448280 3479832
Swap: 2000088 0 2000088

after a few more mins

jaakan@jms1000:~$ free
             total used free shared buffers cached
Mem: 3928112 1006624 2921488 0 77268 481268
-/+ buffers/cache: 448088 3480024
Swap: 2000088 0 2000088

opened Synaptic and removed the test kernel

jaakan@jms1000:~$ free
             total used free shared buffers cached
Mem: 3928112 1003884 2924228 0 17152 545852
-/+ buffers/cache: 440880 3487232
Swap: 2000088 0 2000088

[Jaakan Shorter (jaakanshorter)]

mythtv commercial flagging
when a show in Standard Def. - cache goes up 1Mb ever few seconds
when a show in Hi Def. - cache goes up 1Mb to 10Mb ever second or faster

basically trying to cache the full show in ram

Cache only goes up and never seems to go down without me flushing the cache or rebooting.

[Jeremy Foshee (jeremyfoshee)]

This bug report was marked as Incomplete and has not had any updated comments for quite some time. As a result this bug is being closed. Please reopen if this is still an issue in the current Ubuntu release http://www.ubuntu.com/getubuntu/download . Also, please be sure to provide any requested information that may have been missing. To reopen the bug, click on the current status under the Status column and change the status back to "New". Thanks.

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