From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx175.postini.com [74.125.245.175]) by kanga.kvack.org (Postfix) with SMTP id 0D2246B0044 for ; Wed, 14 Mar 2012 19:43:36 -0400 (EDT) Date: Wed, 14 Mar 2012 16:43:34 -0700 From: Andrew Morton Subject: Re: [PATCH -V3 2/8] memcg: Add HugeTLB extension Message-Id: <20120314164334.5e35f3b6.akpm@linux-foundation.org> In-Reply-To: <87zkbj8ou9.fsf@linux.vnet.ibm.com> References: <1331622432-24683-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1331622432-24683-3-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20120313143316.0ef74d0e.akpm@linux-foundation.org> <87zkbj8ou9.fsf@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Aneesh Kumar K.V" Cc: linux-mm@kvack.org, mgorman@suse.de, kamezawa.hiroyu@jp.fujitsu.com, dhillf@gmail.com, aarcange@redhat.com, mhocko@suse.cz, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org On Wed, 14 Mar 2012 15:51:50 +0530 "Aneesh Kumar K.V" wrote: > On Tue, 13 Mar 2012 14:33:16 -0700, Andrew Morton wrote: > > On Tue, 13 Mar 2012 12:37:06 +0530 > > "Aneesh Kumar K.V" wrote: > > > > > +static int mem_cgroup_hugetlb_usage(struct mem_cgroup *memcg) > > > +{ > > > + int idx; > > > + for (idx = 0; idx < hugetlb_max_hstate; idx++) { > > > + if (memcg->hugepage[idx].usage > 0) > > > + return memcg->hugepage[idx].usage; > > > + } > > > + return 0; > > > +} > > > > Please document the function? Had you done this, I might have been > > able to work out why the function bales out on the first used hugepage > > size, but I can't :( > > I guess the function is named wrongly. I will rename it to > mem_cgroup_have_hugetlb_usage() in the next iteration ? The function > will return (bool) 1 if it has any hugetlb resource usage. > > > > > This could have used for_each_hstate(), had that macro been better > > designed (or updated). > > > > Can you explain this ?. for_each_hstate allows to iterate over > different hstates. But here we need to look at different hugepage > rescounter in memcg. I can still use for_each_hstate() and find the > hstate index (h - hstates) and use that to index memcg rescounter > array. But that would make it more complex ? If the for_each_hstate() macro took an additional arg which holds the base address of the array, that macro could have been used here. Or perhaps not - I didn't look too closely ;) It isn't important. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org