Messages in this thread | | | Date | Mon, 18 May 2009 11:35:14 +0800 | From | Wu Fengguang <> | Subject | Re: [PATCH 3/4] vmscan: zone_reclaim use may_swap |
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On Wed, May 13, 2009 at 12:07:30PM +0900, KOSAKI Motohiro wrote: > Subject: [PATCH] vmscan: zone_reclaim use may_swap > > Documentation/sysctl/vm.txt says > > zone_reclaim_mode: > > Zone_reclaim_mode allows someone to set more or less aggressive approaches to > reclaim memory when a zone runs out of memory. If it is set to zero then no > zone reclaim occurs. Allocations will be satisfied from other zones / nodes > in the system. > > This is value ORed together of > > 1 = Zone reclaim on > 2 = Zone reclaim writes dirty pages out > 4 = Zone reclaim swaps pages > > > So, "(zone_reclaim_mode & RECLAIM_SWAP) == 0" mean we don't want to reclaim > swap-backed pages. not mapped file. > > Thus, may_swap is better than may_unmap. > > > Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> > Cc: Christoph Lameter <cl@linux-foundation.org> > Cc: Rik van Riel <riel@redhat.com> > --- > mm/vmscan.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > Index: b/mm/vmscan.c > =================================================================== > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2387,8 +2387,8 @@ static int __zone_reclaim(struct zone *z > int priority; > struct scan_control sc = { > .may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE), > - .may_unmap = !!(zone_reclaim_mode & RECLAIM_SWAP), > - .may_swap = 1, > + .may_unmap = 1, > + .may_swap = !!(zone_reclaim_mode & RECLAIM_SWAP), > .swap_cluster_max = max_t(unsigned long, nr_pages, > SWAP_CLUSTER_MAX), > .gfp_mask = gfp_mask, >
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
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