lkml.org 
[lkml]   [2010]   [May]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 00/11] V4: rwsem changes + down_read_critical() proposal
On Wed, May 26, 2010 at 10:23:59AM +0900, KAMEZAWA Hiroyuki wrote:
> On Tue, 25 May 2010 11:27:55 +0200
> Peter Zijlstra <peterz@infradead.org> wrote:
> > Also, do you really think doing something like:
> >
> > /*
> > * Check the vma index is within the range and do
> > * sequential scan until m_index.
> > */
> > vma = NULL;
> > if ((unsigned long)l < mm->map_count) {
> > vma = mm->mmap;
> > while (l-- && vma)
> > vma = vma->vm_next;
> > goto out;
> > }
> >
> > with preemption disabled is a _good_ thing?
> >
> > People were talking about raising our vma limit of 64k...

All right, this is clearly a problem then.

> Hmm..can't we use something speculative lookup for reading maps ?
> (as we played in several months ago...)

Would you happen to have a link to that conversation / remember the
subject line of the thread ?

Thanks,

--
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.


\
 
 \ /
  Last update: 2010-05-27 13:05    [from the cache]
©2003-2011 Jasper Spaans