From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wanpeng Li Subject: Re: [PATCH] slub: Don't throw away partial remote slabs if there is no local memory Date: Tue, 7 Jan 2014 16:48:40 +0800 Message-ID: <47097.8799429306$1389084588@news.gmane.org> References: <20140107132100.5b5ad198@kryten> <20140107074136.GA4011@lge.com> Reply-To: Wanpeng Li Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20140107074136.GA4011@lge.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppd-linuxppc64-dev=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" To: Joonsoo Kim Cc: cl@linux-foundation.org, nacc@linux.vnet.ibm.com, penberg@kernel.org, linux-mm@kvack.org, paulus@samba.org, Anton Blanchard , mpm@selenic.com, linuxppc-dev@lists.ozlabs.org List-Id: linux-mm.kvack.org Hi Joonsoo, On Tue, Jan 07, 2014 at 04:41:36PM +0900, Joonsoo Kim wrote: >On Tue, Jan 07, 2014 at 01:21:00PM +1100, Anton Blanchard wrote: >> [...] >Hello, > >I think that we need more efforts to solve unbalanced node problem. > >With this patch, even if node of current cpu slab is not favorable to >unbalanced node, allocation would proceed and we would get the unintended memory. > We have a machine: [ 0.000000] Node 0 Memory: [ 0.000000] Node 4 Memory: 0x0-0x10000000 0x20000000-0x60000000 0x80000000-0xc0000000 [ 0.000000] Node 6 Memory: 0x10000000-0x20000000 0x60000000-0x80000000 [ 0.000000] Node 10 Memory: 0xc0000000-0x180000000 [ 0.041486] Node 0 CPUs: 0-19 [ 0.041490] Node 4 CPUs: [ 0.041492] Node 6 CPUs: [ 0.041495] Node 10 CPUs: The pages of current cpu slab should be allocated from fallback zones/nodes of the memoryless node in buddy system, how can not favorable happen? >And there is one more problem. Even if we have some partial slabs on >compatible node, we would allocate new slab, because get_partial() cannot handle >this unbalance node case. > >To fix this correctly, how about following patch? > So I think we should fold both of your two patches to one. Regards, Wanpeng Li >Thanks. > >------------->8-------------------- >diff --git a/mm/slub.c b/mm/slub.c >index c3eb3d3..a1f6dfa 100644 >--- a/mm/slub.c >+++ b/mm/slub.c >@@ -1672,7 +1672,19 @@ static void *get_partial(struct kmem_cache *s, gfp_t flags, int node, > { > void *object; > int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node; >+ struct zonelist *zonelist; >+ struct zoneref *z; >+ struct zone *zone; >+ enum zone_type high_zoneidx = gfp_zone(flags); > >+ if (!node_present_pages(searchnode)) { >+ zonelist = node_zonelist(searchnode, flags); >+ for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { >+ searchnode = zone_to_nid(zone); >+ if (node_present_pages(searchnode)) >+ break; >+ } >+ } > object = get_partial_node(s, get_node(s, searchnode), c, flags); > if (object || node != NUMA_NO_NODE) > return object; > >-- >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