From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 24 Sep 2007 21:34:29 -0700 (PDT) From: David Rientjes Subject: Re: [patch -mm 4/5] mm: test and set zone reclaim lock before starting reclaim In-Reply-To: <46F88DFB.3020307@linux.vnet.ibm.com> Message-ID: References: <46F88DFB.3020307@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Balbir Singh Cc: Andrew Morton , Andrea Arcangeli , Christoph Lameter , linux-mm@kvack.org List-ID: On Tue, 25 Sep 2007, Balbir Singh wrote: > > + > > + if (zone_test_and_set_flag(zone, ZONE_RECLAIM_LOCKED)) > > + return 0; > > What's the consequence of this on the caller of zone_reclaim()? > I see that the zone is marked as full and will not be re-examined > again. > It's only marked as full in the zonelist cache for the zonelist that __alloc_pages() was called with, which is an optimization. The zone is already flagged as being in __zone_reclaim() so there's no need to reinvoke it for this allocation attempt; that behavior is unchanged from current behavior. One thing that has been changed in -mm with regard to my last patchset is that kswapd and try_to_free_pages() are allowed to call shrink_zone() concurrently. ZONE_RECLAIM_LOCKED will be cleared upon return from __zone_reclaim(). -- 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