From owner-svn-src-head@FreeBSD.ORG Sat Jan 25 20:12:08 2014 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id B9937A94; Sat, 25 Jan 2014 20:12:08 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id A54BF11D3; Sat, 25 Jan 2014 20:12:08 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.7/8.14.7) with ESMTP id s0PJvUR9071676; Sat, 25 Jan 2014 19:57:30 GMT (envelope-from bryanv@svn.freebsd.org) Received: (from bryanv@localhost) by svn.freebsd.org (8.14.7/8.14.7/Submit) id s0PJvUaC071675; Sat, 25 Jan 2014 19:57:30 GMT (envelope-from bryanv@svn.freebsd.org) Message-Id: <201401251957.s0PJvUaC071675@svn.freebsd.org> From: Bryan Venteicher Date: Sat, 25 Jan 2014 19:57:30 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r261167 - head/sys/dev/virtio/network X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 25 Jan 2014 20:12:08 -0000 Author: bryanv Date: Sat Jan 25 19:57:30 2014 New Revision: 261167 URL: http://svnweb.freebsd.org/changeset/base/261167 Log: Avoid queue unlock followed by relock when the enable interrupt race is lost This already happens infrequently, and the hold time is still bounded since we defer to a taskqueue after a few tries. Modified: head/sys/dev/virtio/network/if_vtnet.c Modified: head/sys/dev/virtio/network/if_vtnet.c ============================================================================== --- head/sys/dev/virtio/network/if_vtnet.c Sat Jan 25 19:55:42 2014 (r261166) +++ head/sys/dev/virtio/network/if_vtnet.c Sat Jan 25 19:57:30 2014 (r261167) @@ -1821,9 +1821,9 @@ vtnet_rx_vq_intr(void *xrxq) return; } -again: VTNET_RXQ_LOCK(rxq); +again: if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { VTNET_RXQ_UNLOCK(rxq); return; @@ -1837,10 +1837,11 @@ again: * This is an occasional condition or race (when !more), * so retry a few times before scheduling the taskqueue. */ - rxq->vtnrx_stats.vrxs_rescheduled++; - VTNET_RXQ_UNLOCK(rxq); if (tries++ < VTNET_INTR_DISABLE_RETRIES) goto again; + + VTNET_RXQ_UNLOCK(rxq); + rxq->vtnrx_stats.vrxs_rescheduled++; taskqueue_enqueue(rxq->vtnrx_tq, &rxq->vtnrx_intrtask); } else VTNET_RXQ_UNLOCK(rxq); @@ -2408,9 +2409,9 @@ vtnet_tx_vq_intr(void *xtxq) return; } -again: VTNET_TXQ_LOCK(txq); +again: if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { VTNET_TXQ_UNLOCK(txq); return; @@ -2426,9 +2427,10 @@ again: * This is an occasional race, so retry a few times * before scheduling the taskqueue. */ - VTNET_TXQ_UNLOCK(txq); if (tries++ < VTNET_INTR_DISABLE_RETRIES) goto again; + + VTNET_TXQ_UNLOCK(txq); txq->vtntx_stats.vtxs_rescheduled++; taskqueue_enqueue(txq->vtntx_tq, &txq->vtntx_intrtask); } else