lkml.org 
[lkml]   [2011]   [Jan]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: + mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclai m-avoid-a-potential-deadlock-due-to-lock_page-during-direct-compacti on-fix.patch added to -mm tree
On Tue, Jan 11, 2011 at 01:55:47PM -0800, Andrew Morton wrote:
> On Tue, 11 Jan 2011 13:43:06 -0800 (PST)
> David Rientjes <rientjes@google.com> wrote:
>
> > On Tue, 11 Jan 2011, akpm@linux-foundation.org wrote:
> >
> > > diff -puN mm/page_alloc.c~mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclaim-avoid-a-potential-deadlock-due-to-lock_page-during-direct-compaction-fix mm/page_alloc.c
> > > --- a/mm/page_alloc.c~mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclaim-avoid-a-potential-deadlock-due-to-lock_page-during-direct-compaction-fix
> > > +++ a/mm/page_alloc.c
> > > @@ -1815,15 +1815,15 @@ __alloc_pages_direct_compact(gfp_t gfp_m
> > > int migratetype, unsigned long *did_some_progress)
> > > {
> > > struct page *page;
> > > - struct task_struct *p = current;
> > > + struct task_struct *tsk = current;
> > >
> > > if (!order || compaction_deferred(preferred_zone))
> > > return NULL;
> > >
> > > - p->flags |= PF_MEMALLOC;
> > > + tsk->flags |= PF_MEMALLOC;
> > > *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
> > > nodemask);
> > > - p->flags &= ~PF_MEMALLOC;
> > > + tsk->flags &= ~PF_MEMALLOC;
> > > if (*did_some_progress != COMPACT_SKIPPED) {
> > >
> > > /* Page migration frees to the PCP lists but we want merging */
> >
> > This could be done for all of the page allocator functions in
> > mm/page_alloc.c, I think it would be inconsistent and slightly harder to
> > read if it were done in only one.
>
> Using "p" for any identifier which has less-than-teeny scope is plain
> dumb. It's meaningless and useless.
>
> Anyway...
>
>
> Subject: mm/page_alloc.c: don't cache `current' in a local
> From: Andrew Morton <akpm@linux-foundation.org>
>
> It's old-fashioned and unneeded.
>
> akpm:/usr/src/25> size mm/page_alloc.o
> text data bss dec hex filename
> 39884 1241317 18808 1300009 13d629 mm/page_alloc.o (before)
> 39838 1241317 18808 1299963 13d5fb mm/page_alloc.o (after)
>
> Cc: David Rientjes <rientjes@google.com>
> Cc: Mel Gorman <mel@csn.ul.ie>
> Cc: Hugh Dickins <hughd@google.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Looks spot on. The slight text saving is a bonus and I imagine there are
small savings on stack usage as well.

Acked-by: Mel Gorman <mel@csn.ul.ie>

--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab


\
 
 \ /
  Last update: 2011-01-12 10:31    [W:0.596 / U:0.256 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site