lkml.org 
[lkml]   [2009]   [Dec]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH RFC] [X86] Compile Option Os versus O2 on latest x86 platform
On 12/03/2009 07:03 AM, Ma, Ling wrote:
>> a key question is.. how much more memory do you have free due to -Os?
>> (because memory is cache is performance on a system level as well)
> The kernel code size from Os is 12M, that from O2 is 14M.
>> and how much less icache pressure is there?
> From perf stat report, cache reference(unified cache) from O2 is almost the same with Os.

The icache pressure was substantially higher (by ~10%) in the reports
that I saw.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.



\
 
 \ /
  Last update: 2009-12-03 16:13    [W:0.055 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site