Re: Kernel 3.0: Instant kernel crash when mounting CIFS (also crashes with linux-3.1-rc2

[Justin Piszcz <jpiszcz-BP4nVm5VUdNhbmWW9KSYcQ@public.gmane.org>]

On Fri, 26 Aug 2011, Jeff Layton wrote:

> On Thu, 18 Aug 2011 14:52:57 -0400
> Jeff Layton <jlayton-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org> wrote:
>
>> On Thu, 18 Aug 2011 14:18:15 -0400 (EDT)
>> Justin Piszcz <jpiszcz-BP4nVm5VUdNhbmWW9KSYcQ@public.gmane.org> wrote:
>>
>>>
>> Like I said, read performance with cifs.ko just plain sucks currently.
>>
>> Don't look for cifs.ko to achieve anywhere near NFS' performance unless
>> you jump through some very odd hoops (like multithreading your workload
>> in userspace, etc). cifs.ko just doesn't do a good job of keeping the
>> pipe "stuffed" as most calls are handled synchronously. A single task
>> can only handle one call on the wire in most cases. The exception here
>> is writes, but that just recently changed...
>>
>> Reads are done using relatively small buffers and then copied to
>> pagecache. Part of what I'm working on will be to allow for much larger
>> reads directly into the pagecache. That should also help performance
>> significantly.
>>
>
> I just posted a patchset that should improve the performance of
> buffered reads. It's rather large but should apply to current upstream
> kernels. If you've had problems with cifs.ko read performance in the
> past, then this would be a good time to step up and help test them.
>
> If it makes things easier, then the patchset is also available via the
> cifs-3.2 branch of my public git tree:
>
>    http://git.kernel.org/?p=linux/kernel/git/jlayton/linux.git;a=shortlog;h=refs/heads/cifs-3.2
>
> Thanks,
> -- 
> Jeff Layton <jlayton-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>

Hi Jeff,

This was working earlier..

# mount -t cifs //10.0.1.1/x /mnt -o user=XXXXXXX,pass=XXXXXXXX
mount error(12): Cannot allocate memory
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)

I'll need to contact the owner of the host to see if something has changed as 
this _was_ working previously.

Justin.

>