From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6B677ECAAD8 for ; Fri, 23 Sep 2022 15:16:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=UorYsw2Q0RA5v1p3DScoB0Hc2dP1ZUZpZTV/kkTX85E=; b=46bo3llYG/fZxMkutwtdlsrhcP SjJuwI2/dGy7IHD2E7PDfH059GRBtkLYcy+N7d5zjR37XM/tL7sX6Y67RRD9phe63SgEYtvkHixTT E9vRd/WGsJwM7m8Ff8VqUpac6YSpoT4baC9PbpDCs7cxotSUktkb1s1Q0LZPtPqzIEXZB/2dLoSTd /FNuWzdpK9keLg0L6cePi4ortwQpQnPVBXaFko0PdEXPPSadfzYkMdFN9T5/2y4FycPWQ1q/0vrjy TNAa5A+MLJEQqgKbBsB/l/B2f6Pxpn6sLFVlov8fqZAmpul4kvJP8DZWvuvS2e4tjbMiAaxapy0RQ +PH+4jNg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1obkPj-004lwt-20; Fri, 23 Sep 2022 15:16:27 +0000 Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1obkPg-004lw7-Tj; Fri, 23 Sep 2022 15:16:24 +0000 Date: Fri, 23 Sep 2022 08:16:24 -0700 From: Christoph Hellwig To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-nvme@lists.infradead.org Subject: Re: [PATCHSET 0/5] Enable alloc caching and batched freeing for passthrough Message-ID: References: <20220922182805.96173-1-axboe@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220922182805.96173-1-axboe@kernel.dk> X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Thu, Sep 22, 2022 at 12:28:00PM -0600, Jens Axboe wrote: > This is good for a 10% improvement for passthrough performance. For > a non-drive limited test case, passthrough IO is now more efficient > than the regular bdev O_DIRECT path. How so? If it ends up faster we are doing something wrong in the normal path as there should be no fundamental difference in the work that is being done.