Re: 2.4.20pre5aa2

From: Samuel Flory (sflory@rackable.com)
Date: Thu Sep 12 2002 - 21:14:09 EST


  Stephen is there any reason to leave the system in it's current state?
 (IE You guys want the output of some tool.) Or shall I give it a go at
a kernel with CONFIG_3GB, and maybe play with vmalloc settings?

Samuel Flory wrote:

> Stephen Lord wrote:
>
>> On Thu, 2002-09-12 at 19:23, Andrea Arcangeli wrote:
>>
>>
>>> that seems a bug in xfs, it BUG() if vmap fails, it must not BUG(), it
>>> must return -ENOMEM to userspace instead, or it can try to recollect
>>> and
>>> release some of the other vmalloced entries. Most probably you run into
>>> an address space shortage, not a real ram shortage, so to workaround it
>>> you can recompile with CONFIG_2G and it'll probably work, also dropping
>>> the gap page in vmalloc may help workaround it (there's no config
>>> option
>>> for it though). It could be also a vmap leak, maybe a missing vfree,
>>> just some idea.
>>>
>>>
>>
>>
>> We hold vmalloced space for very short periods of time, in fact
>> filesystem recovery and large extended attributes are the only
>> cases. In this case we should be attempting to remap 2 pages
>> together. The only way out of this would be to fail the whole
>> mount at this point. I suspect a leak elsewhere.
>>
>> Samuel, when you mounted xfs and it oopsed, was it shortly after bootup?
>>
>
> Yes I'd just logged in and manually mounted it.
>
>> Also, how far did your dbench run get before it hung? I tried the
>> kernel, but I paniced during startup - then I realized I did not
>> apply the patch to fix the xfs/scheduler interactions first.
>>
>>
> It looked around 1/4 to 1/2 done with dbench 32. I'm not sure if it
> was the 1st or second run. I run dbench from a script:
> sync
> sync
> ./dbench 2
> sync
> sync
> ./dbench 4
> sync
> sync
> ./dbench 8
> sync
> sync
> ./dbench 16
> sync
> sync
> ./dbench 32
> sync
> sync
> ./dbench 64
> sync
> sync
> <repeats >
>
> I generally use this script narrow down which configurations seem to
> be most promising.
>
>> How much memory is in the machine by the way?
>
> 4G ram, and 4G swap.
>
>
>
>

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This archive was generated by hypermail 2b29 : Sun Sep 15 2002 - 22:00:31 EST