Re: Memory usage per memory zone

[jack marrow]

2009/3/11 Wu Fengguang <fengguang.wu@xxxxxxxxx>:
> On Wed, Mar 11, 2009 at 01:51:32PM +0200, jack marrow wrote:
>> 2009/3/11 Wu Fengguang <fengguang.wu@xxxxxxxxx>:
>> > Hi jack,
>> >
>> > On Wed, Mar 11, 2009 at 11:41:43AM +0100, jack marrow wrote:
>> >> Hello,
>> >>
>> >> I have a box where the oom-killer is killing processes due to running
>> >> out of memory in zone_normal. I can see using slabtop that the inode
>> >
>> > How do you know that the memory pressure on zone normal stand out alone?
>>
>> For the normal zone only, I see "all_unreclaimable: yes" and 3 megs of free ram:
>>
>> kernel: Normal free:2576kB min:3728kB low:7456kB high:11184kB
>> active:1304kB inactive:128kB present:901120kB pages_scanned:168951
>> all_unreclaimable? yes
>
> It's normal behavior.  Linux kernel tries hard to utilize most of
> the free memory for caching files :)

With all_unreclaimable = yes is normal?

>
>> >> caches are using up lots of memory and guess this is the problem, so
>> >> have cleared them using an echo to drop_caches.
>> >
>> > It would better be backed by concrete numbers...
>> >
>> >>
>> >> I would quite like to not guess though - is it possible to use slabtop
>> >> (or any other way) to view ram usage per zone so I can pick out the
>> >> culprit?
>> >
>> > /proc/zoneinfo and /proc/vmstat do have some per-zone numbers.
>> > Some of them deal with slabs.
>>
>> Thanks, I'll read up on how to interpret these.
>>
>> Do you recommend these two files for tracking down memory usage per
>> process per zone?
>
> No, the two interfaces provide system wide counters.  We have the well
> known tools "ps" and "top" for per-process numbers, hehe.

ps and top do not have per-zone numbers. How do I get those?

>
> Thanks,
> Fengguang
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