From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx151.postini.com [74.125.245.151]) by kanga.kvack.org (Postfix) with SMTP id 7F8C66B004D for ; Fri, 15 Jun 2012 06:06:22 -0400 (EDT) Received: from /spool/local by e23smtp03.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 15 Jun 2012 09:55:36 +1000 Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q5FA6Etk46792906 for ; Fri, 15 Jun 2012 20:06:14 +1000 Received: from d23av04.au.ibm.com (loopback [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q5FA6DAZ029513 for ; Fri, 15 Jun 2012 20:06:13 +1000 From: "Aneesh Kumar K.V" Subject: Re: [PATCH -V9 11/15] hugetlb/cgroup: Add charge/uncharge routines for hugetlb cgroup In-Reply-To: <20120614092539.GI27397@tiehlicka.suse.cz> References: <1339583254-895-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1339583254-895-12-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20120614092539.GI27397@tiehlicka.suse.cz> Date: Fri, 15 Jun 2012 15:36:10 +0530 Message-ID: <87k3z8nb3h.fsf@skywalker.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, kamezawa.hiroyu@jp.fujitsu.com, dhillf@gmail.com, rientjes@google.com, akpm@linux-foundation.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Michal Hocko writes: > On Wed 13-06-12 15:57:30, Aneesh Kumar K.V wrote: >> From: "Aneesh Kumar K.V" >> >> This patchset add the charge and uncharge routines for hugetlb cgroup. >> We do cgroup charging in page alloc and uncharge in compound page >> destructor. Assigning page's hugetlb cgroup is protected by hugetlb_lock. >> >> Signed-off-by: Aneesh Kumar K.V > > Reviewed-by: Michal Hocko > > One minor comment > [...] >> +void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages, >> + struct hugetlb_cgroup *h_cg, >> + struct page *page) >> +{ >> + if (hugetlb_cgroup_disabled() || !h_cg) >> + return; >> + >> + spin_lock(&hugetlb_lock); >> + set_hugetlb_cgroup(page, h_cg); >> + spin_unlock(&hugetlb_lock); >> + return; >> +} > > I guess we can remove the lock here because nobody can see the page yet, > right? > We need that to make sure when we remove cgroup we find correct page hugetlb cgroup values. But i guess we have a bug here. How about the below ? NOTE: We also need another patch to update active list during soft offline. I will send that in reply. commit e4c3fd3cc0f0faa30ea283cb48ba478a5c0d3e74 Author: Aneesh Kumar K.V Date: Fri Jun 15 14:42:27 2012 +0530 hugetlb/cgroup: Assign the page hugetlb cgroup when we move the page to active list. page's hugetlb cgroup assign and moving to active list should happen with hugetlb_lock held. Otherwise when we remove the hugetlb cgroup we would iterate the active list and will find page with NULL hugetlb cgroup values. Signed-off-by: Aneesh Kumar K.V diff --git a/mm/hugetlb.c b/mm/hugetlb.c index ee4da3b..b90dfb4 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1146,9 +1146,12 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma, } spin_lock(&hugetlb_lock); page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve); - spin_unlock(&hugetlb_lock); - - if (!page) { + if (page) { + /* update page cgroup details */ + hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); + spin_unlock(&hugetlb_lock); + } else { + spin_unlock(&hugetlb_lock); page = alloc_buddy_huge_page(h, NUMA_NO_NODE); if (!page) { hugetlb_cgroup_uncharge_cgroup(idx, @@ -1159,14 +1162,13 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma, } spin_lock(&hugetlb_lock); list_move(&page->lru, &h->hugepage_activelist); + hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); spin_unlock(&hugetlb_lock); } set_page_private(page, (unsigned long)spool); vma_commit_reservation(h, vma, addr); - /* update page cgroup details */ - hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); return page; } diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c index 8e7ca0a..d4f3f7b 100644 --- a/mm/hugetlb_cgroup.c +++ b/mm/hugetlb_cgroup.c @@ -218,6 +218,7 @@ done: return ret; } +/* Should be called with hugetlb_lock held */ void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages, struct hugetlb_cgroup *h_cg, struct page *page) @@ -225,9 +226,7 @@ void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages, if (hugetlb_cgroup_disabled() || !h_cg) return; - spin_lock(&hugetlb_lock); set_hugetlb_cgroup(page, h_cg); - spin_unlock(&hugetlb_lock); return; } -- 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