From patchwork Tue May 4 00:10:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Simmons X-Patchwork-Id: 12237267 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,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 2C284C433B4 for ; Tue, 4 May 2021 00:11:00 +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 D363361185 for ; Tue, 4 May 2021 00:10:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D363361185 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass 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 70AC921F82C; Mon, 3 May 2021 17:10:43 -0700 (PDT) Received: from smtp3.ccs.ornl.gov (smtp3.ccs.ornl.gov [160.91.203.39]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id B83C721F597 for ; Mon, 3 May 2021 17:10:24 -0700 (PDT) Received: from star.ccs.ornl.gov (star.ccs.ornl.gov [160.91.202.134]) by smtp3.ccs.ornl.gov (Postfix) with ESMTP id 36A51EE4; Mon, 3 May 2021 20:10:20 -0400 (EDT) Received: by star.ccs.ornl.gov (Postfix, from userid 2004) id 3573F8AD3E; Mon, 3 May 2021 20:10:20 -0400 (EDT) From: James Simmons To: Andreas Dilger , Oleg Drokin , NeilBrown Date: Mon, 3 May 2021 20:10:12 -0400 Message-Id: <1620087016-17857-11-git-send-email-jsimmons@infradead.org> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1620087016-17857-1-git-send-email-jsimmons@infradead.org> References: <1620087016-17857-1-git-send-email-jsimmons@infradead.org> Subject: [lustre-devel] [PATCH 10/14] lnet: Skip discovery in LNetPrimaryNID if DD disabled 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: Chris Horn , Lustre Development List MIME-Version: 1.0 Errors-To: lustre-devel-bounces@lists.lustre.org Sender: "lustre-devel" From: Chris Horn If discovery is disabled locally then the discovery thread will not modify any peer objects as a result of the discovery process. Thus, the primary NID of any peer we're asked to discover will not change as a result of discovery. Therefore, we do not need to actually perform discovery in LNetPrimaryNID() if discovery is disabled locally. Since this routine can result in long client mount times when a Lustre server is down we should avoid this unnecessary discovery. HPE-bug-id: LUS-9887 WC-bug-id: https://jira.whamcloud.com/browse/LU-14566 Lustre-commit: 16264da9e3c43a63 ("LU-14566 lnet: Skip discovery in LNetPrimaryNID if DD disabled") Signed-off-by: Chris Horn Reviewed-on: https://review.whamcloud.com/43141 Reviewed-by: Serguei Smirnov Reviewed-by: James Simmons Reviewed-by: Oleg Drokin Signed-off-by: James Simmons --- net/lnet/lnet/peer.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/net/lnet/lnet/peer.c b/net/lnet/lnet/peer.c index db00514..d66a302 100644 --- a/net/lnet/lnet/peer.c +++ b/net/lnet/lnet/peer.c @@ -1336,7 +1336,13 @@ struct lnet_peer_ni * } lp = lpni->lpni_peer_net->lpn_peer; - while (!lnet_peer_is_uptodate(lp)) { + /* If discovery is disabled locally then we needn't bother running + * discovery here because discovery will not modify whatever + * primary NID is currently set for this peer. If the specified peer is + * down then this discovery can introduce long delays into the mount + * process, so skip it if it isn't necessary. + */ + while (!lnet_peer_discovery_disabled && !lnet_peer_is_uptodate(lp)) { spin_lock(&lp->lp_lock); /* force a full discovery cycle */ lp->lp_state |= LNET_PEER_FORCE_PING | LNET_PEER_FORCE_PUSH; @@ -1357,7 +1363,11 @@ struct lnet_peer_ni * } lp = lpni->lpni_peer_net->lpn_peer; - /* Only try once if discovery is disabled */ + /* If we find that the peer has discovery disabled then we will + * not modify whatever primary NID is currently set for this + * peer. Thus, we can break out of this loop even if the peer + * is not fully up to date. + */ if (lnet_is_discovery_disabled(lp)) break; }