lkml.org 
[lkml]   [2009]   [Apr]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH V3] Fix Committed_AS underflow
From
Date
On Mon, 2009-04-20 at 10:09 +0100, Eric B Munson wrote:
> 1. Change NR_CPUS to min(64, NR_CPUS)
> This will limit the amount of possible skew on kernels compiled for very
> large SMP machines. 64 is an arbitrary number selected to limit the worst
> of the skew without using more cache lines. min(64, NR_CPUS) is used
> instead of nr_online_cpus() because nr_online_cpus() requires a shared
> cache line and a call to hweight to make the calculation. Its runtime
> overhead and keeping this counter accurate showed up in profiles and it's
> possible that nr_online_cpus() would also show.



-- Dave



\
 
 \ /
  Last update: 2009-04-20 18:19    [W:0.057 / U:0.652 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site