From owner-svn-src-head@freebsd.org Mon Feb 18 14:21:42 2019 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 7E8C214DD371; Mon, 18 Feb 2019 14:21:42 +0000 (UTC) (envelope-from vmaffione@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 1B02A6A03C; Mon, 18 Feb 2019 14:21:42 +0000 (UTC) (envelope-from vmaffione@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 0B59A702E; Mon, 18 Feb 2019 14:21:42 +0000 (UTC) (envelope-from vmaffione@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x1IELfNQ027287; Mon, 18 Feb 2019 14:21:41 GMT (envelope-from vmaffione@FreeBSD.org) Received: (from vmaffione@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x1IELfEP027285; Mon, 18 Feb 2019 14:21:41 GMT (envelope-from vmaffione@FreeBSD.org) Message-Id: <201902181421.x1IELfEP027285@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: vmaffione set sender to vmaffione@FreeBSD.org using -f From: Vincenzo Maffione Date: Mon, 18 Feb 2019 14:21:41 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r344253 - head/sys/dev/netmap X-SVN-Group: head X-SVN-Commit-Author: vmaffione X-SVN-Commit-Paths: head/sys/dev/netmap X-SVN-Commit-Revision: 344253 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 1B02A6A03C X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.95 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.998,0]; NEURAL_HAM_SHORT(-0.96)[-0.957,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US]; NEURAL_HAM_LONG(-1.00)[-0.999,0] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 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: Mon, 18 Feb 2019 14:21:42 -0000 Author: vmaffione Date: Mon Feb 18 14:21:41 2019 New Revision: 344253 URL: https://svnweb.freebsd.org/changeset/base/344253 Log: netmap: don't schedule kqueue notify task when kqueue is not used This change adds a counter (kqueue_users) to keep track of how many kqueue users are referencing a given struct nm_selinfo. In this way, nm_os_selwakeup() can schedule the kevent notification task only when kqueue is actually being used. This is important to avoid wasting CPU in the common case where kqueue is not used. Reviewed by: Aleksandr Fedorov MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D19177 Modified: head/sys/dev/netmap/netmap_freebsd.c head/sys/dev/netmap/netmap_kern.h Modified: head/sys/dev/netmap/netmap_freebsd.c ============================================================================== --- head/sys/dev/netmap/netmap_freebsd.c Mon Feb 18 13:14:53 2019 (r344252) +++ head/sys/dev/netmap/netmap_freebsd.c Mon Feb 18 14:21:41 2019 (r344253) @@ -105,6 +105,7 @@ int nm_os_selinfo_init(NM_SELINFO_T *si, const char *n snprintf(si->mtxname, sizeof(si->mtxname), "nmkl%s", name); mtx_init(&si->m, si->mtxname, NULL, MTX_DEF); knlist_init_mtx(&si->si.si_note, &si->m); + si->kqueue_users = 0; return (0); } @@ -1351,7 +1352,9 @@ void nm_os_selwakeup(struct nm_selinfo *si) { selwakeuppri(&si->si, PI_NET); - taskqueue_enqueue(si->ntfytq, &si->ntfytask); + if (si->kqueue_users > 0) { + taskqueue_enqueue(si->ntfytq, &si->ntfytask); + } } void @@ -1364,20 +1367,28 @@ static void netmap_knrdetach(struct knote *kn) { struct netmap_priv_d *priv = (struct netmap_priv_d *)kn->kn_hook; - struct selinfo *si = &priv->np_si[NR_RX]->si; + struct nm_selinfo *si = priv->np_si[NR_RX]; - nm_prinf("remove selinfo %p", si); - knlist_remove(&si->si_note, kn, /*islocked=*/0); + knlist_remove(&si->si.si_note, kn, /*islocked=*/0); + NMG_LOCK(); + KASSERT(si->kqueue_users > 0, ("kqueue_user underflow on %s", + si->mtxname)); + si->kqueue_users--; + nm_prinf("kqueue users for %s: %d", si->mtxname, si->kqueue_users); + NMG_UNLOCK(); } static void netmap_knwdetach(struct knote *kn) { struct netmap_priv_d *priv = (struct netmap_priv_d *)kn->kn_hook; - struct selinfo *si = &priv->np_si[NR_TX]->si; + struct nm_selinfo *si = priv->np_si[NR_TX]; - nm_prinf("remove selinfo %p", si); - knlist_remove(&si->si_note, kn, /*islocked=*/0); + knlist_remove(&si->si.si_note, kn, /*islocked=*/0); + NMG_LOCK(); + si->kqueue_users--; + nm_prinf("kqueue users for %s: %d", si->mtxname, si->kqueue_users); + NMG_UNLOCK(); } /* @@ -1465,6 +1476,10 @@ netmap_kqfilter(struct cdev *dev, struct knote *kn) kn->kn_fop = (ev == EVFILT_WRITE) ? &netmap_wfiltops : &netmap_rfiltops; kn->kn_hook = priv; + NMG_LOCK(); + si->kqueue_users++; + nm_prinf("kqueue users for %s: %d", si->mtxname, si->kqueue_users); + NMG_UNLOCK(); knlist_add(&si->si.si_note, kn, /*islocked=*/0); return 0; Modified: head/sys/dev/netmap/netmap_kern.h ============================================================================== --- head/sys/dev/netmap/netmap_kern.h Mon Feb 18 13:14:53 2019 (r344252) +++ head/sys/dev/netmap/netmap_kern.h Mon Feb 18 14:21:41 2019 (r344253) @@ -132,11 +132,14 @@ struct netmap_adapter *netmap_getna(if_t ifp); #define MBUF_QUEUED(m) 1 struct nm_selinfo { + /* Support for select(2) and poll(2). */ struct selinfo si; + /* Support for kqueue(9). See comments in netmap_freebsd.c */ struct taskqueue *ntfytq; struct task ntfytask; struct mtx m; char mtxname[32]; + int kqueue_users; };