Re: fs/stat: Reduce memory requirements for stat_open

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 25 Jun 2014 15:52:30 -0700 (PDT) David Rientjes <rientjes@google.com> wrote:

> On Wed, 25 Jun 2014, Stefan Bader wrote:
> 
> > Heiko and I both had the same issue. Since some x86 hardware also reaches a lot
> > of CPUs (hyperthreads included), we bumped the possible number of CPUs to 256 at
> > least for the 64bit kernel. And that resulted in failed accesses to /proc/stat
> > when memory became fragmented.
> > So the first patch will avoid this on most systems. I have not seen this myself,
> > but I would expect him to be happy with 1/2 already. For really excessive
> > hardware 2/2 will close the gap.
> > Since this is no critical bug, I am fine with 3.17, too. I have not done so,
> > yet, but I could let our reporter try the patches (again, probably not verifying
> > the second part). Just waited to do so to see whether the code settles down to
> > these changes.
> > 
> 
> Ok, thanks.  Looks like
> 
> proc-stat-convert-to-single_open_size.patch
> fs-seq_file-fallback-to-vmalloc-allocation.patch
> 
> are destined for 3.17.

Actually I've bumped them into the 3.16 queue, cc stable.