From nobody Fri Oct 3 11:28:53 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1579807157; cv=none; d=zohomail.com; s=zohoarc; b=VWQuCfvLI+dAPwhzkqvrmwdIze9LwdLohbSxoVGvSHccJLwcaJwL4HZrzL2pT92b0L4MCSOvG9uBtK5++Pme7AxXV2ybc4yHtQkSId7S4Zjk/tzHPiXCKxrKVbX3CyYPUz+DeEajh1XJTmuGw6NAPjZwnxacLtpIFzp3VJs3H2g= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1579807157; h=Content-Type:Content-Transfer-Encoding:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=xPTFVLKkpPqpNGMFw2Pb4zQ3DPr6AATTIVJBUAAy3pk=; b=I2UawKEWG4keKgXNa2EMfW7fNkGRshPigyEThad1o/bVum/vKPAKnaXtckblueQawqcrVaXH3cGWNvNsaHYaKiiggyO38WAj1MDfNP28jzbg+gog9A3LxkPPBMo5oeGvec8GEZo4HDUyqIRkUhsaDibKiBwY/64FMy6ENvcJyv8= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1579807157687240.0245095396158; Thu, 23 Jan 2020 11:19:17 -0800 (PST) Received: from localhost ([::1]:35546 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iui0Z-0006h6-Ft for importer@patchew.org; Thu, 23 Jan 2020 14:19:15 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:42649) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iuff4-0006EX-0I for qemu-devel@nongnu.org; Thu, 23 Jan 2020 11:48:55 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iuff1-0000E9-Q7 for qemu-devel@nongnu.org; Thu, 23 Jan 2020 11:48:53 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:21168 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iuff1-0000DN-NA for qemu-devel@nongnu.org; Thu, 23 Jan 2020 11:48:51 -0500 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-342-OgWC6KlXMrud1H1WTFIAig-1; Thu, 23 Jan 2020 11:48:49 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 306D48C84CC for ; Thu, 23 Jan 2020 16:48:48 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-116-110.ams2.redhat.com [10.36.116.110]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2BD3228993; Thu, 23 Jan 2020 16:48:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579798131; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xPTFVLKkpPqpNGMFw2Pb4zQ3DPr6AATTIVJBUAAy3pk=; b=N3JAtRXsEXYwayd12rpqTvH21XRCxzrTe11ccQ0CtIC7akQHzdxP64+yn9Bph6zVSwlrd+ NI879OQLt5mC/yeN/A40ttAdriYcbxGHhq0UcrhLHV/X/jleuHJjhJH+sep2omfaA+X838 QoWHOfNQvth7gYaa1c3c02KbTQkHGHM= From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com Subject: [PULL 100/108] virtiofsd: use fuse_buf_writev to replace fuse_buf_write for better performance Date: Thu, 23 Jan 2020 16:46:22 +0000 Message-Id: <20200123164630.91498-101-dgilbert@redhat.com> In-Reply-To: <20200123164630.91498-1-dgilbert@redhat.com> References: <20200123164630.91498-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: OgWC6KlXMrud1H1WTFIAig-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @redhat.com) Content-Type: text/plain; charset="utf-8" From: piaojun fuse_buf_writev() only handles the normal write in which src is buffer and dest is fd. Specially if src buffer represents guest physical address that can't be mapped by the daemon process, IO must be bounced back to the VMM to do it by fuse_buf_copy(). Signed-off-by: Jun Piao Suggested-by: Dr. David Alan Gilbert Suggested-by: Stefan Hajnoczi Reviewed-by: Daniel P. Berrang=C3=A9 Signed-off-by: Dr. David Alan Gilbert --- tools/virtiofsd/buffer.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/tools/virtiofsd/buffer.c b/tools/virtiofsd/buffer.c index 37befebac2..27c1377f22 100644 --- a/tools/virtiofsd/buffer.c +++ b/tools/virtiofsd/buffer.c @@ -34,7 +34,6 @@ size_t fuse_buf_size(const struct fuse_bufvec *bufv) return size; } =20 -__attribute__((unused)) static ssize_t fuse_buf_writev(struct fuse_buf *out_buf, struct fuse_bufvec *in_buf) { @@ -262,12 +261,29 @@ static int fuse_bufvec_advance(struct fuse_bufvec *bu= fv, size_t len) =20 ssize_t fuse_buf_copy(struct fuse_bufvec *dstv, struct fuse_bufvec *srcv) { - size_t copied =3D 0; + size_t copied =3D 0, i; =20 if (dstv =3D=3D srcv) { return fuse_buf_size(dstv); } =20 + /* + * use writev to improve bandwidth when all the + * src buffers already mapped by the daemon + * process + */ + for (i =3D 0; i < srcv->count; i++) { + if (srcv->buf[i].flags & FUSE_BUF_IS_FD) { + break; + } + } + if ((i =3D=3D srcv->count) && (dstv->count =3D=3D 1) && + (dstv->idx =3D=3D 0) && + (dstv->buf[0].flags & FUSE_BUF_IS_FD)) { + dstv->buf[0].pos +=3D dstv->off; + return fuse_buf_writev(&dstv->buf[0], srcv); + } + for (;;) { const struct fuse_buf *src =3D fuse_bufvec_current(srcv); const struct fuse_buf *dst =3D fuse_bufvec_current(dstv); --=20 2.24.1