lkml.org 
[lkml]   [2006]   [May]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch 00/14] remap_file_pages protection support
Blaisorblade wrote:
>> I've not seen much of this if any at all, the various caches that are in
>> place for these lookups seem to function quite well; what we did see was
>> glibc's malloc implementation being mistuned resulting in far too many
>> mmaps than needed (which in turn leads to far too much page zeroing
>> which is the really expensive part. It's not the vma lookup that is
>> expensive, it's the page zeroing)
> Even to this email, I hope Ulrich will answer.

All I can say is that some of our guys tuning a big application on a
customer's site reported seeing the VMA lookups being on the profile
list. This was some huge Java program. It might be that every other
page had a different protection, executable or not, read-only mmap etc.
And data access for very non-local.

I cannot say more since this was near to the end of the trials.

--
➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖

[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2006-05-03 03:49    [W:0.077 / U:0.084 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site