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 X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89C88C43466 for ; Sun, 20 Sep 2020 08:40:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4309421BE5 for ; Sun, 20 Sep 2020 08:40:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726392AbgITIkE (ORCPT ); Sun, 20 Sep 2020 04:40:04 -0400 Received: from mail3-relais-sop.national.inria.fr ([192.134.164.104]:24862 "EHLO mail3-relais-sop.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726298AbgITIkD (ORCPT ); Sun, 20 Sep 2020 04:40:03 -0400 X-Greylist: delayed 427 seconds by postgrey-1.27 at vger.kernel.org; Sun, 20 Sep 2020 04:40:02 EDT X-IronPort-AV: E=Sophos;i="5.77,282,1596492000"; d="scan'208";a="359510816" Received: from abo-173-121-68.mrs.modulonet.fr (HELO hadrien) ([85.68.121.173]) by mail3-relais-sop.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Sep 2020 10:32:54 +0200 Date: Sun, 20 Sep 2020 10:32:54 +0200 (CEST) From: Julia Lawall X-X-Sender: jll@hadrien To: Joe Perches cc: Christophe JAILLET , akpm@linux-foundation.org, natechancellor@gmail.com, geert+renesas@glider.be, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] lib/scatterlist: Avoid a double memset In-Reply-To: Message-ID: References: <20200920071544.368841-1-christophe.jaillet@wanadoo.fr> User-Agent: Alpine 2.22 (DEB 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 20 Sep 2020, Joe Perches wrote: > On Sun, 2020-09-20 at 09:15 +0200, Christophe JAILLET wrote: > > 'sgl' is zeroed a few lines below in 'sg_init_table()'. There is no need to > > clear it twice. > > > > Remove the redundant initialization. > > I didn't look very thoroughly, but there are at least > a few more of these with kcalloc and kzalloc like > > block/bsg-lib.c- size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments); > block/bsg-lib.c- > block/bsg-lib.c- BUG_ON(!req->nr_phys_segments); > block/bsg-lib.c- > block/bsg-lib.c- buf->sg_list = kzalloc(sz, GFP_KERNEL); > block/bsg-lib.c- if (!buf->sg_list) > block/bsg-lib.c- return -ENOMEM; > block/bsg-lib.c: sg_init_table(buf->sg_list, req->nr_phys_segments); > --- > drivers/target/target_core_rd.c- sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg), > drivers/target/target_core_rd.c- GFP_KERNEL); > drivers/target/target_core_rd.c- if (!sg) > drivers/target/target_core_rd.c- return -ENOMEM; > drivers/target/target_core_rd.c- > drivers/target/target_core_rd.c: sg_init_table(sg, sg_per_table + chain_entry); > --- > net/rds/rdma.c- sg = kcalloc(nents, sizeof(*sg), GFP_KERNEL); > net/rds/rdma.c- if (!sg) { > net/rds/rdma.c- ret = -ENOMEM; > net/rds/rdma.c- goto out; > net/rds/rdma.c- } > net/rds/rdma.c- WARN_ON(!nents); > net/rds/rdma.c: sg_init_table(sg, nents); I found 16 occurrences in the following files: net/rds/rdma.c drivers/infiniband/hw/efa/efa_verbs.c drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c drivers/misc/mic/scif/scif_nodeqp.c block/bsg-lib.c drivers/dma/sh/rcar-dmac.c drivers/spi/spi-topcliff-pch.c net/sunrpc/xprtrdma/frwr_ops.c drivers/dma/imx-dma.c drivers/pci/p2pdma.c drivers/dma/sh/shdma-base.c drivers/target/target_core_rd.c drivers/media/common/saa7146/saa7146_core.c drivers/tty/serial/pch_uart.c drivers/net/wireless/intel/iwlwifi/fw/dbg.c julia