From owner-freebsd-fs@FreeBSD.ORG Thu Jul 25 02:18:35 2013 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id BD7D4C78 for ; Thu, 25 Jul 2013 02:18:35 +0000 (UTC) (envelope-from araujobsdport@gmail.com) Received: from mail-we0-x233.google.com (mail-we0-x233.google.com [IPv6:2a00:1450:400c:c03::233]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 512072642 for ; Thu, 25 Jul 2013 02:18:35 +0000 (UTC) Received: by mail-we0-f179.google.com with SMTP id t57so96993wes.24 for ; Wed, 24 Jul 2013 19:18:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:reply-to:date:message-id:subject:from:to:content-type; bh=laaXxzuC8JtY7Qmq3dkzaBunxG7Iv1YwXKeHY5+GJV0=; b=qIhdYOrA/yfC0k3VwlGWjRX2kYDf3Sx+A3bNCXk7eeitIlMc6Snm++yCsP65w5Ryor pmFHerZkx0txNfOAsX52VAdySNNOaINO12kfagLUQaWJ5T3+bXPjSK+cOczSQcwbmcXY +IaYBu4MXXtD2d6TR9ghA8Zer6ydLZE1eI0FIkQEf6dvHFrTg5nS/kYtFgmWf4p+QZAI useCDjNMwovhGiMyzo4tDhmV7UmieGe5tJLkEX6437tyZ8Wg9T51qS0R0QIy+ez4sab5 s6uFmWYKL8eS0bqSIelKAIkuf697lEwwjW85daiuuhi65SMNgham3u5+FI79jdMgR6my s8PQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:reply-to:date:message-id:subject:from:to:content-type; bh=laaXxzuC8JtY7Qmq3dkzaBunxG7Iv1YwXKeHY5+GJV0=; b=kHb21UsvX9zC9VbSr+UiJxhBzTVlbd8J99vN19I1OiGd6lyu50vQyuawB8OvSZKCKz +pCcYU1QnWXgzhhU80To8Pb6xbX1+FzgPIOUtIoxO1cZrhsQR7giKS1L6c0aVeg6EyHV fqhBcJzPp7CgppaoVwHzyW35aHQkWv+vjEwUp6CabN28wCB3Tispkd3wAbovT1vkpL+q 7winpgTsLuHCvwwG8qmMPyX+ewk7vdFluYyBgEOkJo3UcmfSW80HkFsCXdN/urYlzTCG gjxQhjtPnIHExssUMsrtXcFakps0guoktBYWDunMZGVF6WY1ZcokHcliiSqYm9CPV3W3 ZEBQ== MIME-Version: 1.0 X-Received: by 10.180.126.2 with SMTP id mu2mr261628wib.63.1374718713587; Wed, 24 Jul 2013 19:18:33 -0700 (PDT) Received: by 10.216.214.198 with HTTP; Wed, 24 Jul 2013 19:18:33 -0700 (PDT) Date: Thu, 25 Jul 2013 10:18:33 +0800 Message-ID: Subject: Samba + ZFS + sendfile() From: Marcelo Araujo To: "freebsd-fs@freebsd.org" Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: araujo@FreeBSD.org List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 25 Jul 2013 02:18:35 -0000 Hello Guys, I'm doing some benchmarks and also implement a new syscal recvfile() for zero copy. Pretty much similar like sendfile(2). However, using sendfile with Samba + ZFS has a very bad performance if we compare with Samba + sendfile() + UFS. I asked some people and they said it is because the data is cached twice once in ARC and in a second time on VFS cache. I got really confused with this approach, and I'm wondering if someone could give me some explanation how it happens. Best Regards, -- Marcelo Araujo araujo@FreeBSD.org