From patchwork Fri Jun 14 02:53:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 10994057 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 33A8A1398 for ; Fri, 14 Jun 2019 02:53:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 278EA232A7 for ; Fri, 14 Jun 2019 02:53:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1ADD026E3A; Fri, 14 Jun 2019 02:53:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D2AB626E3C for ; Fri, 14 Jun 2019 02:53:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725942AbfFNCx0 (ORCPT ); Thu, 13 Jun 2019 22:53:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51828 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725864AbfFNCx0 (ORCPT ); Thu, 13 Jun 2019 22:53:26 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 79A4D30832CD; Fri, 14 Jun 2019 02:53:25 +0000 (UTC) Received: from localhost (ovpn-8-21.pek2.redhat.com [10.72.8.21]) by smtp.corp.redhat.com (Postfix) with ESMTP id 18A0B607BC; Fri, 14 Jun 2019 02:53:21 +0000 (UTC) From: Ming Lei To: linux-scsi@vger.kernel.org, "Martin K . Petersen" Cc: James Bottomley , Bart Van Assche , Hannes Reinecke , Christoph Hellwig , Jim Gill , Cathy Avery , "Ewan D . Milne" , Brian King , James Smart , "Juergen E . Fischer" , Michael Schmitz , Finn Thain , Greg Kroah-Hartman , devel@driverdev.osuosl.org, linux-usb@vger.kernel.org, Dan Carpenter , Benjamin Block , Ming Lei Subject: [PATCH V3 00/15] use sg helper to operate scatterlist Date: Fri, 14 Jun 2019 10:53:01 +0800 Message-Id: <20190614025316.7360-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Fri, 14 Jun 2019 02:53:25 +0000 (UTC) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Hi, Scsi MQ makes a large static allocation for the first scatter gather list chunk for the driver to use. This is a performance headache we'd like to fix by reducing the size of the allocation to a 2 element array. Doing this will break the current guarantee that any driver using SG_ALL doesn't need to use the scatterlist iterators and can get away with directly dereferencing the array. Thus we need to update all drivers to use the scatterlist iterators and remove direct indexing of the scatterlist array before reducing the initial scatterlist allocation size in SCSI. So convert drivers to use scatterlist helper. There are two types of scsi SGL uses: 1) operate on scsi_sglist(scmd) directly, then one local variable of 'struct scatterlist *' is involved, so the following coccinelle semantic patch is developed for finding this type of direct sgl uses: https://marc.info/?l=linux-scsi&m=156031374809852&w=2 2) scsi_sglist(scmd) is stored to cmd->SCp.buffer and the SGL is used via cmd->SCp.buffer. Simple 'grep SCp.buffer' is used for finding SGL direct uses, fortunately only the following drivers uses SCp.buffer to store SGL: NCR5380, aha152x, arm/, imm, pcmcia, ppa and wd33c93 And arm/ is already ready to handle chained SGL. The 1st 9 patches are for handling type #1, and the other 6 patches for handling type #2. V3: - update commit log and cover letter, most of words are from James Bottomley V2: - use coccinelle semantic patch for finding direct sgl uses from scsi command(9 drivers found) - run 'git grep -E "SCp.buffer"' to find direct sgl uses from SCp.buffer(6 drivers are found) Finn Thain (1): NCR5380: Support chained sg lists Ming Lei (14): scsi: vmw_pscsi: use sg helper to operate scatterlist scsi: advansys: use sg helper to operate scatterlist scsi: lpfc: use sg helper to operate scatterlist scsi: mvumi: use sg helper to operate scatterlist scsi: ipr: use sg helper to operate scatterlist scsi: pmcraid: use sg helper to operate scatterlist usb: image: microtek: use sg helper to operate scatterlist staging: unisys: visorhba: use sg helper to operate scatterlist s390: zfcp_fc: use sg helper to operate scatterlist scsi: aha152x: use sg helper to operate scatterlist scsi: imm: use sg helper to operate scatterlist scsi: pcmcia: nsp_cs: use sg helper to operate scatterlist scsi: ppa: use sg helper to operate scatterlist scsi: wd33c93: use sg helper to operate scatterlist drivers/s390/scsi/zfcp_fc.c | 4 +- drivers/scsi/NCR5380.c | 41 ++++++++----------- drivers/scsi/advansys.c | 2 +- drivers/scsi/aha152x.c | 29 ++++++++----- drivers/scsi/imm.c | 2 +- drivers/scsi/ipr.c | 28 +++++++------ drivers/scsi/lpfc/lpfc_nvmet.c | 3 +- drivers/scsi/mvumi.c | 9 ++-- drivers/scsi/pcmcia/nsp_cs.c | 4 +- drivers/scsi/pmcraid.c | 12 +++--- drivers/scsi/ppa.c | 2 +- drivers/scsi/vmw_pvscsi.c | 2 +- drivers/scsi/wd33c93.c | 2 +- .../staging/unisys/visorhba/visorhba_main.c | 9 ++-- drivers/usb/image/microtek.c | 20 ++++----- drivers/usb/image/microtek.h | 2 +- 16 files changed, 85 insertions(+), 86 deletions(-)