Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757136AbbKRVsh (ORCPT ); Wed, 18 Nov 2015 16:48:37 -0500 Received: from gum.cmpxchg.org ([85.214.110.215]:44380 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756900AbbKRVsg (ORCPT ); Wed, 18 Nov 2015 16:48:36 -0500 Date: Wed, 18 Nov 2015 16:48:22 -0500 From: Johannes Weiner To: Michal Hocko Cc: David Miller , Andrew Morton , Vladimir Davydov , Tejun Heo , netdev@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 13/14] mm: memcontrol: account socket memory in unified hierarchy memory controller Message-ID: <20151118214822.GA1365@cmpxchg.org> References: <1447371693-25143-1-git-send-email-hannes@cmpxchg.org> <1447371693-25143-14-git-send-email-hannes@cmpxchg.org> <20151116155923.GH14116@dhcp22.suse.cz> <20151116181810.GB32544@cmpxchg.org> <20151118162256.GK19145@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151118162256.GK19145@dhcp22.suse.cz> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1828 Lines: 43 On Wed, Nov 18, 2015 at 05:22:56PM +0100, Michal Hocko wrote: > On Mon 16-11-15 13:18:10, Johannes Weiner wrote: > > What load would you test and what would be the baseline to compare it > > to? > > It seems like netperf with a stream load running in a memcg with no > limits vs. in root memcg (and no other cgroups) should give at least a > hint about the runtime overhead, no? Comparing root vs. dedicated group generally doesn't make sense since you either need containment or you don't. It makes more sense to test both times inside a memory-controlled cgroup, one with a regular boot, one with cgroup.memory=nosocket. So I ran perf record -g -a netperf -t TCP_STREAM multiple times inside a memory-controlled cgroup, but mostly mem_cgroup_charge_skmem() does not show up in the profile at all. Once it was there with 0.00%. I ran another test that downloads the latest kernel image from kernel.org at 13MB/s (on my i5 laptop) and it looks like this: 0.02% 0.01% irq/44-iwlwifi [kernel.kallsyms] [k] mem_cgroup_charge_skmem | ---mem_cgroup_charge_skmem __sk_mem_schedule tcp_try_rmem_schedule tcp_data_queue tcp_rcv_established tcp_v4_do_rcv tcp_v4_rcv ip_local_deliver ip_rcv __netif_receive_skb_core __netif_receive_skb netif_receive_skb_internal napi_gro_complete The runs vary too much for this to be measurable in elapsed time. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/