From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 21 Aug 2008 08:14:04 -0500 From: Robin Holt Subject: Re: [RFC][PATCH 0/2] Quicklist is slighly problematic. Message-ID: <20080821131404.GC26567@sgi.com> References: <20080820195021.12E7.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20080820113131.f032c8a2.akpm@linux-foundation.org> <20080821024240.GC23397@sgi.com> <48AD689F.6080103@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48AD689F.6080103@linux-foundation.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Robin Holt , Andrew Morton , KOSAKI Motohiro , linux-kernel@vger.kernel.org, linux-mm@kvack.org, tokunaga.keiich@jp.fujitsu.com, stable@kernel.org List-ID: On Thu, Aug 21, 2008 at 08:07:43AM -0500, Christoph Lameter wrote: > Robin Holt wrote: > > > > Index: ia64-cleanups/include/linux/quicklist.h > > =================================================================== > > --- ia64-cleanups.orig/include/linux/quicklist.h 2008-08-20 21:35:10.000000000 -0500 > > +++ ia64-cleanups/include/linux/quicklist.h 2008-08-20 21:38:00.891943270 -0500 > > @@ -66,6 +66,15 @@ static inline void __quicklist_free(int > > > > static inline void quicklist_free(int nr, void (*dtor)(void *), void *pp) > > { > > +#ifdef CONFIG_NUMA > > + unsigned long nid = page_to_nid(virt_to_page(pp)); > > + > > + if (unlikely(nid != numa_node_id())) { > > + free_page((unsigned long)pp); > > + return; > > + } > > +#endif > > + > > __quicklist_free(nr, dtor, pp, virt_to_page(pp)); > > } > > > > We removed this code because it frees a page before the TLB flush has been > performed. This code segment was the reason that quicklists were not accepted > for x86. How could we do this. It was a _HUGE_ problem on altix boxes. When you started a jobs with a large number of MPI ranks, they would all start from the shepherd process on a single node and the children would migrate to a different cpu. Unless subsequent jobs used enough memory to flush those remote quicklists, we would end up with a depleted node that never reclaimed. Thanks, Robin -- 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