lkml.org 
[lkml]   [2012]   [Mar]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [rfc][patches] fix for munmap/truncate races
On Sun, Mar 18, 2012 at 10:06:10PM +0000, Al Viro wrote:
> On Sun, Mar 18, 2012 at 03:01:08PM -0700, Linus Torvalds wrote:
> > On Sun, Mar 18, 2012 at 12:07 PM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> > > - ? ? ? tlb_finish_mmu(&tlb, 0, end);
> > > + ? ? ? tlb_finish_mmu(&tlb, 0, -1);
> > Hmm. The fact that you drop the end pointer means that some
> > architectures that optimize the TLB flushing for ranges now
> > effectively can't do it any more.
> >
> > Now, I think it's only ia64 that really is affected, but it *might* matter.
> >
> > In particular, ia64 has some logic for "if you only flush one single
> > region, you can optimize it", and the region sizes are in the
> > terabytes. And I'm pretty sure you broke that - I'm just not entirely
> > sure how much we care.
>
> Nope - ia64 check explicitly for precisely that case:
[snip]
... and everything else doesn't look at start or end at all.


\
 
 \ /
  Last update: 2012-03-18 23:11    [W:0.056 / U:1.188 seconds]
©2003-2014 Jasper Spaans. Advertise on this site