From patchwork Fri May 5 19:46:25 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 98726 Delivered-To: patch@linaro.org Received: by 10.140.96.100 with SMTP id j91csp293460qge; Fri, 5 May 2017 12:50:10 -0700 (PDT) X-Received: by 10.98.86.207 with SMTP id h76mr3660830pfj.205.1494013714471; Fri, 05 May 2017 12:48:34 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 144si6012850pfa.118.2017.05.05.12.48.34; Fri, 05 May 2017 12:48:34 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755603AbdEETsd (ORCPT + 6 others); Fri, 5 May 2017 15:48:33 -0400 Received: from mout.kundenserver.de ([212.227.126.187]:61369 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755521AbdEETsU (ORCPT ); Fri, 5 May 2017 15:48:20 -0400 Received: from wuerfel.lan ([78.42.17.5]) by mrelayeu.kundenserver.de (mreue002 [212.227.15.129]) with ESMTPA (Nemesis) id 0M6rkj-1e0s7v1cwv-00wi3U; Fri, 05 May 2017 21:48:06 +0200 From: Arnd Bergmann To: Ben Hutchings Cc: stable@vger.kernel.org, Gerald Schaefer , "Kirill A . Shutemov" , Vlastimil Babka , Mike Kravetz , "Aneesh Kumar K . V" , Martin Schwidefsky , Heiko Carstens , Rui Teng , Dave Hansen , Andrew Morton , Linus Torvalds , Arnd Bergmann Subject: [PATCH 3.16-stable 07/87] mm/hugetlb: improve locking in dissolve_free_huge_pages() Date: Fri, 5 May 2017 21:46:25 +0200 Message-Id: <20170505194745.3627137-8-arnd@arndb.de> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20170505194745.3627137-1-arnd@arndb.de> References: <20170505194745.3627137-1-arnd@arndb.de> X-Provags-ID: V03:K0:BL9NbL8yI42SPn/qi5ykWQigrMO2xymwRaMF6FA2TSYy78EcOW0 CsMaJhq+d+la02m22GNOjEL18MpKCdbpJizD/j8E2MulpPuRVLNAsYutlZ4ZMXTVd04PE9e bHlGxJyovEf02HZ6X/EiJqstSruT130SFl08y0Oqt4kvo5KF4rD4Jhrb4HF45D0DsT2Judv gCXhfkz9z27qCw28ILPjg== X-UI-Out-Filterresults: notjunk:1; V01:K0:4XN2uK/urxs=:FaEAzdD0h0j+n8FSYmtQqP IkiSFPOhBLrUxS7OvQIyZj87gkcyjFufoAFLV3ygxmMHSnUEelUAC0PhCS85hzCZi1G5xivMe r0CvCiIIq0+uXZ21M6BcGg64NoQAFz6ZHtsEYkasEE7KeHJiiwzkfexjahNajelPp9m8bFv0p WoGf0TaeNftNiMwGxRBkzjMDnwYqEcfyH6sXlWjALJaAI5eMD3WgmqKG/9vFDhn6i9AcPyEA+ 4pW2wX4oh39Ewp/mIwDcI8MtP2rZ8x4QM6tuSWNjpwCWwUSg67oEPVETRtPJKf/7r8DLGP0kX xxmkRSUBmCtknYvHNU6F8IEQEvAcWr/1fcnQXXq1wsnF8sA7IZrtGcDs+QuTsjZLnPZacR5qW YCsvw7IwSimVDtUMXQSrD2TmmdUYIfBrjNDqZAU2XoytC4vOOdyykaej6ND6Lv7m+nw3UY1GK TCfmU2DNvy6vQj0iUWuNrjJtCsnm1lNJhYTRBdHjUcpuDlVsB4oM5VgW/GYvq2WXV/SYS90AS CEw1luf+k6AbKkAKMuP5FDi2zsl5+YuLKvLmvEolD8KDs/Gok9Gb34jcUFTLNk7caaqJor3oU WDYXb0Ego6WBHB9r8otFnjeubKrLYDlR+IG7DdxY4HFBQCLkjItqq//tOQKUBoy+MxiEjv1P4 FIXTgNDcEqqA7LD2fPm/c7ZTHoBxtg4iqulM0pMWBhTugu2xH/KJ4cWeUAWT8PPzn0FE= Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Gerald Schaefer Commit 7b21d5b87b550c5cdaca73bd37c976cc1ab85398 upstream. For every pfn aligned to minimum_order, dissolve_free_huge_pages() will call dissolve_free_huge_page() which takes the hugetlb spinlock, even if the page is not huge at all or a hugepage that is in-use. Improve this by doing the PageHuge() and page_count() checks already in dissolve_free_huge_pages() before calling dissolve_free_huge_page(). In dissolve_free_huge_page(), when holding the spinlock, those checks need to be revalidated. Link: http://lkml.kernel.org/r/20160926172811.94033-4-gerald.schaefer@de.ibm.com Signed-off-by: Gerald Schaefer Acked-by: Michal Hocko Acked-by: Naoya Horiguchi Cc: "Kirill A . Shutemov" Cc: Vlastimil Babka Cc: Mike Kravetz Cc: "Aneesh Kumar K . V" Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Rui Teng Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Arnd Bergmann --- mm/hugetlb.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) -- 2.9.0 diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 467d04b62948..c892a6b51e8e 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1105,14 +1105,20 @@ out: int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) { unsigned long pfn; + struct page *page; int rc = 0; if (!hugepages_supported()) return rc; - for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) - if (rc = dissolve_free_huge_page(pfn_to_page(pfn))) - break; + for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) { + page = pfn_to_page(pfn); + if (PageHuge(page) && !page_count(page)) { + rc = dissolve_free_huge_page(page); + if (rc) + break; + } + } return rc; }