lkml.org 
[lkml]   [2011]   [Oct]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH] Reduce vm_stat cacheline contention in __vm_enough_memory
Date
Mel Gorman <mel@csn.ul.ie> writes:
>
> If vm_enough_memory is being heavily hit as well, it implies that this
> workload is mmap-intensive which is pretty inefficient in itself. I

Saw it with tmpfs originally. No need to be mmap intensive. Just
do lots of IOs on tmpfs.

> guess it would also apply to workloads that are malloc-intensive for
> large buffers but I'd expect the cache line bounces to only dominate if
> there was little or no computation on the resulting buffers.

I think you severly underestimate the costs of bouncing cache lines
on >2S.

> As a result, I wonder how realistic is this test workload and who useful
> fixing this problem is in general?

It's kind of bad if tmpfs doesn't scale.

-Andi

--
ak@linux.intel.com -- Speaking for myself only


\
 
 \ /
  Last update: 2011-10-13 18:03    [W:0.068 / U:0.144 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site