Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756933Ab3CNLbF (ORCPT ); Thu, 14 Mar 2013 07:31:05 -0400 Received: from e28smtp05.in.ibm.com ([122.248.162.5]:51396 "EHLO e28smtp05.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756746Ab3CNLbD (ORCPT ); Thu, 14 Mar 2013 07:31:03 -0400 From: Wanpeng Li To: Andrew Morton Cc: Greg Kroah-Hartman , Michal Hocko , "Aneesh Kumar K.V" , Hillf Danton , KAMEZAWA Hiroyuki , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Wanpeng Li Subject: [PATCH v3] mm/hugetlb: fix total hugetlbfs pages count when memory overcommit accouting Date: Thu, 14 Mar 2013 19:30:46 +0800 Message-Id: <1363260646-26896-1-git-send-email-liwanp@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.5.4 X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13031411-8256-0000-0000-0000069D3100 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2069 Lines: 61 Changelog: v2 -> v3: * update patch description, spotted by Michal v1 -> v2: * update patch description, spotted by Michal "hugetlb_total_pages is used for overcommit calculations but the current implementation considers only default hugetlb page size (which is either the first defined hugepage size or the one specified by default_hugepagesz kernel boot parameter). If the system is configured for more than one hugepage size (which is possible since a137e1cc hugetlbfs: per mount huge page sizes) then the overcommit estimation done by __vm_enough_memory (resp. shown by meminfo_proc_show) is not precise - there is an impression of more available/allowed memory. This can lead to an unexpected ENOMEM/EFAULT resp. SIGSEGV when memory is accounted." The patch should also push to 2.6.27 stable tree. Testcase: boot: hugepagesz=1G hugepages=1 the default overcommit ratio is 50 before patch: egrep 'CommitLimit' /proc/meminfo CommitLimit: 55434168 kB after patch: egrep 'CommitLimit' /proc/meminfo CommitLimit: 54909880 kB Signed-off-by: Wanpeng Li --- mm/hugetlb.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index cdb64e4..9e25040 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2124,8 +2124,11 @@ int hugetlb_report_node_meminfo(int nid, char *buf) /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ unsigned long hugetlb_total_pages(void) { - struct hstate *h = &default_hstate; - return h->nr_huge_pages * pages_per_huge_page(h); + struct hstate *h; + unsigned long nr_total_pages = 0; + for_each_hstate(h) + nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); + return nr_total_pages; } static int hugetlb_acct_memory(struct hstate *h, long delta) -- 1.7.11.7 -- 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/