From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <46F13B6C.7020501@redhat.com> Date: Wed, 19 Sep 2007 11:08:28 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [RFC 13/26] SLUB: Add SlabReclaimable() to avoid repeated reclaim attempts References: <20070901014107.719506437@sgi.com> <20070901014222.303468369@sgi.com> In-Reply-To: <20070901014222.303468369@sgi.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Andy Whitcroft , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Christoph Hellwig , Mel Gorman , David Chinner List-ID: Christoph Lameter wrote: > Add a flag SlabReclaimable() that is set on slabs with a method > that allows defrag/reclaim. Clear the flag if a reclaim action is not > successful in reducing the number of objects in a slab. The reclaim > flag is set again if all objects have been allocated from it. > > Signed-off-by: Christoph Lameter > --- > mm/slub.c | 42 ++++++++++++++++++++++++++++++++++++------ > 1 file changed, 36 insertions(+), 6 deletions(-) > > Index: linux-2.6/mm/slub.c > =================================================================== > --- linux-2.6.orig/mm/slub.c 2007-08-28 20:10:37.000000000 -0700 > +++ linux-2.6/mm/slub.c 2007-08-28 20:10:47.000000000 -0700 > @@ -107,6 +107,8 @@ > #define SLABDEBUG 0 > #endif > > +#define SLABRECLAIMABLE (1 << PG_dirty) > + > static inline int SlabFrozen(struct page *page) > { > return page->flags & FROZEN; > @@ -137,6 +139,21 @@ static inline void ClearSlabDebug(struct > page->flags &= ~SLABDEBUG; > } > > +static inline int SlabReclaimable(struct page *page) > +{ > + return page->flags & SLABRECLAIMABLE; > +} > + > +static inline void SetSlabReclaimable(struct page *page) > +{ > + page->flags |= SLABRECLAIMABLE; > +} > + > +static inline void ClearSlabReclaimable(struct page *page) > +{ > + page->flags &= ~SLABRECLAIMABLE; > +} Why is it safe to not use the normal page flag bit operators for these page flags operations? -- Politics is the struggle between those who want to make their country the best in the world, and those who believe it already is. Each group calls the other unpatriotic. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org