lkml.org 
[lkml]   [2009]   [Nov]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 0/7] Kill PF_MEMALLOC abuse
On Tue, Nov 17, 2009 at 09:24:24PM +0900, KOSAKI Motohiro wrote:
> > On Tue, Nov 17, 2009 at 07:24:42PM +0900, KOSAKI Motohiro wrote:
> > > if xfsbufd doesn't only write out dirty data but also drop page,
> > > I agree you.
> >
> > It then drops the reference to the buffer which drops references to the
> > pages, which often are the last references, yes.
>
> I though it is not typical case. Am I wrong?
> if so, I'm sorry. I'm not XFS expert.

I think in the typical case it's the last reference. The are two
reasons why it might not be:

- we're on a filesystem with block size < page size in which case two
buffers can share a page and we'd need to write out and release both
buffers to free the page
- someone else might have a reference on the buffer. Offhand I can't
remember a place where we do this for delayed write buffers (which
is what xfsbufd writes out) as it would be a bit against the purpose
of those delayed write buffers.



\
 
 \ /
  Last update: 2009-11-17 13:51    [W:0.190 / U:0.428 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site