From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e32.co.us.ibm.com (e32.co.us.ibm.com [32.97.110.150]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id D9C321A01D2 for ; Wed, 23 Jul 2014 09:47:37 +1000 (EST) Received: from /spool/local by e32.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 22 Jul 2014 17:47:34 -0600 Received: from b03cxnp08026.gho.boulder.ibm.com (b03cxnp08026.gho.boulder.ibm.com [9.17.130.18]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id CA35D1FF0041 for ; Tue, 22 Jul 2014 17:47:31 -0600 (MDT) Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by b03cxnp08026.gho.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s6MNkI8f3604890 for ; Wed, 23 Jul 2014 01:46:18 +0200 Received: from d03av03.boulder.ibm.com (localhost [127.0.0.1]) by d03av03.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s6MNlVNH004733 for ; Tue, 22 Jul 2014 17:47:32 -0600 Date: Tue, 22 Jul 2014 16:47:26 -0700 From: Nishanth Aravamudan To: David Rientjes Subject: Re: [RFC PATCH 2/3] topology: support node_numa_mem() for determining the fallback node Message-ID: <20140722234726.GO4156@linux.vnet.ibm.com> References: <1391674026-20092-2-git-send-email-iamjoonsoo.kim@lge.com> <20140207054819.GC28952@lge.com> <20140210010936.GA12574@lge.com> <20140722010305.GJ4156@linux.vnet.ibm.com> <20140722214311.GM4156@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20140722214311.GM4156@linux.vnet.ibm.com> Cc: Han Pingtian , Pekka Enberg , Linux Memory Management List , Paul Mackerras , Anton Blanchard , Matt Mackall , Tejun Heo , Joonsoo Kim , linuxppc-dev@lists.ozlabs.org, Christoph Lameter , Wanpeng Li List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 22.07.2014 [14:43:11 -0700], Nishanth Aravamudan wrote: > Hi David, > on powerpc now, things look really good. On a KVM instance with the > following topology: > > available: 2 nodes (0-1) > node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 > node 0 size: 0 MB > node 0 free: 0 MB > node 1 cpus: 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 > node 1 size: 16336 MB > node 1 free: 14274 MB > node distances: > node 0 1 > 0: 10 40 > 1: 40 10 > > 3.16.0-rc6 gives: > > Slab: 1039744 kB > SReclaimable: 38976 kB > SUnreclaim: 1000768 kB > Adding my patch on top of Joonsoo's and the revert, I get: > > Slab: 411776 kB > SReclaimable: 40960 kB > SUnreclaim: 370816 kB > > So CONFIG_SLUB still uses about 3x as much slab memory, but it's not so > much that we are close to OOM with small VM/LPAR sizes. Just to clarify/add one more datapoint, with a balanced topology: available: 2 nodes (0-1) node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 node 0 size: 8154 MB node 0 free: 8075 MB node 1 cpus: 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 node 1 size: 8181 MB node 1 free: 7776 MB node distances: node 0 1 0: 10 40 1: 40 10 I see the following for my patch + Joonsoo's + the revert: Slab: 495872 kB SReclaimable: 46528 kB SUnreclaim: 449344 kB (Although these numbers fluctuate quite a bit between 250M and 500M), which indicates that the memoryless node slab consumption is now on-par with a populated topology. And both are still more than CONFIG_SLAB requires. Thanks, Nish