From owner-svn-src-all@freebsd.org Fri Oct 23 15:46:43 2015 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id D9329A1D9D3; Fri, 23 Oct 2015 15:46:43 +0000 (UTC) (envelope-from royger@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 mx1.freebsd.org (Postfix) with ESMTPS id 8CC35C0F; Fri, 23 Oct 2015 15:46:43 +0000 (UTC) (envelope-from royger@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id t9NFkg9F020962; Fri, 23 Oct 2015 15:46:42 GMT (envelope-from royger@FreeBSD.org) Received: (from royger@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id t9NFkggN020961; Fri, 23 Oct 2015 15:46:42 GMT (envelope-from royger@FreeBSD.org) Message-Id: <201510231546.t9NFkggN020961@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: royger set sender to royger@FreeBSD.org using -f From: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= Date: Fri, 23 Oct 2015 15:46:42 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r289836 - head/sys/dev/xen/blkfront X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Oct 2015 15:46:43 -0000 Author: royger Date: Fri Oct 23 15:46:42 2015 New Revision: 289836 URL: https://svnweb.freebsd.org/changeset/base/289836 Log: blkfront: add support for unmapped IO Using unmapped IO is really beneficial when running inside of a VM, since it avoids IPIs to other vCPUs in order to invalidate the mappings. This patch adds unmapped IO support to blkfront. The following tests results have been obtained when running on a Xen host without HAP: PVHVM 3165.84 real 6354.17 user 4483.32 sys PVHVM with unmapped IO 2099.46 real 4624.52 user 2967.38 sys This is because when running using shadow page tables TLB flushes and range invalidations are much more expensive, so using unmapped IO provides a very important performance boost. Sponsored by: Citrix Systems R&D MFC after: 2 weeks X-MFC-with: r289834 Modified: head/sys/dev/xen/blkfront/blkfront.c Modified: head/sys/dev/xen/blkfront/blkfront.c ============================================================================== --- head/sys/dev/xen/blkfront/blkfront.c Fri Oct 23 15:40:44 2015 (r289835) +++ head/sys/dev/xen/blkfront/blkfront.c Fri Oct 23 15:46:42 2015 (r289836) @@ -293,8 +293,12 @@ xbd_queue_request(struct xbd_softc *sc, { int error; - error = bus_dmamap_load(sc->xbd_io_dmat, cm->cm_map, cm->cm_data, - cm->cm_datalen, xbd_queue_cb, cm, 0); + if (cm->cm_bp != NULL) + error = bus_dmamap_load_bio(sc->xbd_io_dmat, cm->cm_map, + cm->cm_bp, xbd_queue_cb, cm, 0); + else + error = bus_dmamap_load(sc->xbd_io_dmat, cm->cm_map, + cm->cm_data, cm->cm_datalen, xbd_queue_cb, cm, 0); if (error == EINPROGRESS) { /* * Maintain queuing order by freezing the queue. The next @@ -354,8 +358,6 @@ xbd_bio_command(struct xbd_softc *sc) } cm->cm_bp = bp; - cm->cm_data = bp->bio_data; - cm->cm_datalen = bp->bio_bcount; cm->cm_sector_number = (blkif_sector_t)bp->bio_pblkno; switch (bp->bio_cmd) { @@ -1009,7 +1011,7 @@ xbd_instance_create(struct xbd_softc *sc sc->xbd_disk->d_mediasize = sectors * sector_size; sc->xbd_disk->d_maxsize = sc->xbd_max_request_size; - sc->xbd_disk->d_flags = 0; + sc->xbd_disk->d_flags = DISKFLAG_UNMAPPED_BIO; if ((sc->xbd_flags & (XBDF_FLUSH|XBDF_BARRIER)) != 0) { sc->xbd_disk->d_flags |= DISKFLAG_CANFLUSHCACHE; device_printf(sc->xbd_dev,