From patchwork Mon Mar 23 16:54:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Disseldorp X-Patchwork-Id: 11453501 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BAFA71667 for ; Mon, 23 Mar 2020 16:54:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A1B3E206C3 for ; Mon, 23 Mar 2020 16:54:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727559AbgCWQyZ (ORCPT ); Mon, 23 Mar 2020 12:54:25 -0400 Received: from mx2.suse.de ([195.135.220.15]:50422 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727164AbgCWQyY (ORCPT ); Mon, 23 Mar 2020 12:54:24 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 3A426AB8F; Mon, 23 Mar 2020 16:54:23 +0000 (UTC) From: David Disseldorp To: target-devel@vger.kernel.org Cc: linux-scsi@vger.kernel.org, martin.petersen@oracle.com, bvanassche@acm.org Subject: [RFC PATCH 0/5] scsi: target: XCOPY performance Date: Mon, 23 Mar 2020 17:54:05 +0100 Message-Id: <20200323165410.24423-1-ddiss@suse.de> X-Mailer: git-send-email 2.16.4 Sender: target-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: target-devel@vger.kernel.org These changes remove unnecessary heap allocations in the XCOPY READ/WRITE dispatch loop. Synthetic benchmarks on my laptop using the libiscsi iscsi-dd utility (--xcopy --max 1 --blocks 65535 src=dst) against a target backed by an 8G zram (DEBUG_KMEMLEAK=y) iblock backstore (avg across four runs) show: before: 5.35776G/s after: 6.12636G/s (approx. +14%) Feedback appreciated. Cheers, David ---------------------------------------------------------------- David Disseldorp (5): scsi: target: use #def for xcopy descriptor len scsi: target: drop xcopy DISK BLOCK LENGTH debug scsi: target: avoid per-loop XCOPY buffer allocations scsi: target: increase XCOPY I/O size scsi: target: avoid XCOPY per-loop read/write cmd allocations drivers/target/target_core_xcopy.c | 135 ++++++++++------------------- drivers/target/target_core_xcopy.h | 14 +-- 2 files changed, 57 insertions(+), 92 deletions(-)