From patchwork Mon Sep 30 18:55:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Simmons X-Patchwork-Id: 11167241 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EC5B216C1 for ; Mon, 30 Sep 2019 19:04:54 +0000 (UTC) Received: from pdx1-mailman02.dreamhost.com (pdx1-mailman02.dreamhost.com [64.90.62.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D5215224EF for ; Mon, 30 Sep 2019 19:04:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D5215224EF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lustre-devel-bounces@lists.lustre.org Received: from pdx1-mailman02.dreamhost.com (localhost [IPv6:::1]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id 1900D5E48A7; Mon, 30 Sep 2019 12:00:21 -0700 (PDT) X-Original-To: lustre-devel@lists.lustre.org Delivered-To: lustre-devel-lustre.org@pdx1-mailman02.dreamhost.com Received: from smtp4.ccs.ornl.gov (smtp4.ccs.ornl.gov [160.91.203.40]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id 91FFA5C3C36 for ; Mon, 30 Sep 2019 11:57:27 -0700 (PDT) Received: from star.ccs.ornl.gov (star.ccs.ornl.gov [160.91.202.134]) by smtp4.ccs.ornl.gov (Postfix) with ESMTP id 4CCE01005C86; Mon, 30 Sep 2019 14:56:57 -0400 (EDT) Received: by star.ccs.ornl.gov (Postfix, from userid 2004) id 4B868B4; Mon, 30 Sep 2019 14:56:57 -0400 (EDT) From: James Simmons To: Andreas Dilger , Oleg Drokin , NeilBrown Date: Mon, 30 Sep 2019 14:55:50 -0400 Message-Id: <1569869810-23848-92-git-send-email-jsimmons@infradead.org> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1569869810-23848-1-git-send-email-jsimmons@infradead.org> References: <1569869810-23848-1-git-send-email-jsimmons@infradead.org> Subject: [lustre-devel] [PATCH 091/151] lustre: llite: avoid live-lock when concurrent mmap()s X-BeenThere: lustre-devel@lists.lustre.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "For discussing Lustre software development." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Lustre Development List MIME-Version: 1.0 Errors-To: lustre-devel-bounces@lists.lustre.org Sender: "lustre-devel" From: Bruno Faccini Patch is an attempt to delay page-fault retry from Client side for inode with extents being mmap()'ed, to prevent live-lock situation to occur with other page's competitors. WC-bug-id: https://jira.whamcloud.com/browse/LU-10149 Lustre-commit: cd793b4067b6 ("LU-10149 llite: avoid live-lock when concurrent mmap()s") Signed-off-by: Bruno Faccini Reviewed-on: https://review.whamcloud.com/30465 Reviewed-by: Andreas Dilger Reviewed-by: Bobi Jam Reviewed-by: Jinshan Xiong Reviewed-by: Oleg Drokin Signed-off-by: James Simmons --- fs/lustre/llite/llite_mmap.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/fs/lustre/llite/llite_mmap.c b/fs/lustre/llite/llite_mmap.c index 59fb400..14080b6 100644 --- a/fs/lustre/llite/llite_mmap.c +++ b/fs/lustre/llite/llite_mmap.c @@ -38,6 +38,7 @@ #include #include #include +#include #include #include @@ -153,7 +154,7 @@ static int __ll_page_mkwrite(struct vm_area_struct *vma, struct page *vmpage, int result; u16 refcheck; sigset_t old, new; - struct inode *inode; + struct inode *inode = NULL; struct ll_inode_info *lli; env = cl_env_get(&refcheck); @@ -229,6 +230,17 @@ static int __ll_page_mkwrite(struct vm_area_struct *vma, struct page *vmpage, CDEBUG(D_MMAP, "%s mkwrite with %d\n", current->comm, result); LASSERT(ergo(result == 0, PageLocked(vmpage))); + /* if page has been unmapped, presumably due to lock reclaim for + * concurrent usage, add some delay before retrying to prevent + * entering live-lock situation with competitors + */ + if (result == -ENODATA && inode) { + CDEBUG(D_MMAP, + "delaying new page-fault for inode %p to prevent live-lock\n", + inode); + msleep(20); + } + return result; }