From patchwork Thu Jan 21 17:16:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Simmons X-Patchwork-Id: 12037141 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E120C433E0 for ; Thu, 21 Jan 2021 17:17:13 +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 A283123A57 for ; Thu, 21 Jan 2021 17:17:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A283123A57 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 2C92421FBD5; Thu, 21 Jan 2021 09:17:11 -0800 (PST) Received: from smtp4.ccs.ornl.gov (smtp4.ccs.ornl.gov [160.91.203.40]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id E0E3A21FA40 for ; Thu, 21 Jan 2021 09:17:06 -0800 (PST) Received: from star.ccs.ornl.gov (star.ccs.ornl.gov [160.91.202.134]) by smtp4.ccs.ornl.gov (Postfix) with ESMTP id 2785F1007AB9; Thu, 21 Jan 2021 12:17:05 -0500 (EST) Received: by star.ccs.ornl.gov (Postfix, from userid 2004) id 1D7F11158C; Thu, 21 Jan 2021 12:17:05 -0500 (EST) From: James Simmons To: Andreas Dilger , Oleg Drokin , NeilBrown Date: Thu, 21 Jan 2021 12:16:25 -0500 Message-Id: <1611249422-556-3-git-send-email-jsimmons@infradead.org> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1611249422-556-1-git-send-email-jsimmons@infradead.org> References: <1611249422-556-1-git-send-email-jsimmons@infradead.org> Subject: [lustre-devel] [PATCH 02/39] lustre: ptlrpc: fixes for RCU-related stalls 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: Andrew Perepechko , Lustre Development List MIME-Version: 1.0 Errors-To: lustre-devel-bounces@lists.lustre.org Sender: "lustre-devel" From: Andrew Perepechko ptlrpc_expired_set() may need to process a lot of requests, so the processing loop needs to schedule from time to time to avoid RCU-related stalls. HPE-bug-id: LUS-8939 WC-bug-id: https://jira.whamcloud.com/browse/LU-13822 Lustre-commit: 1bbd5b5f0ee042 ("LU-13822 ptlrpc: fixes for RCU-related stalls") Signed-off-by: Andrew Perepechko Reviewed-on: https://review.whamcloud.com/39514 Reviewed-by: Alexander Zarochentsev Reviewed-by: Neil Brown Reviewed-by: Oleg Drokin Signed-off-by: James Simmons --- fs/lustre/ptlrpc/client.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/lustre/ptlrpc/client.c b/fs/lustre/ptlrpc/client.c index 0e01ab33..2002c03 100644 --- a/fs/lustre/ptlrpc/client.c +++ b/fs/lustre/ptlrpc/client.c @@ -2249,6 +2249,11 @@ void ptlrpc_expired_set(struct ptlrpc_request_set *set) * ptlrpcd thread. */ ptlrpc_expire_one_request(req, 1); + /* + * Loops require that we resched once in a while to avoid + * RCU stalls and a few other problems. + */ + cond_resched(); } }