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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 9CCC4C2BA19 for ; Mon, 6 Apr 2020 13:54:05 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 535D922582 for ; Mon, 6 Apr 2020 13:54:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 535D922582 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arndb.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48wsTR1HBkzDr1Z for ; Mon, 6 Apr 2020 23:54:03 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=arndb.de (client-ip=212.227.126.134; helo=mout.kundenserver.de; envelope-from=arnd@arndb.de; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=arndb.de Received: from mout.kundenserver.de (mout.kundenserver.de [212.227.126.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 48wrZC2BTjzDqtl for ; Mon, 6 Apr 2020 23:13:06 +1000 (AEST) Received: from mail-qk1-f173.google.com ([209.85.222.173]) by mrelayeu.kundenserver.de (mreue010 [212.227.15.129]) with ESMTPSA (Nemesis) id 1MEmMt-1jVahp2edv-00GKvH for ; Mon, 06 Apr 2020 15:13:02 +0200 Received: by mail-qk1-f173.google.com with SMTP id o18so13180358qko.12 for ; Mon, 06 Apr 2020 06:13:02 -0700 (PDT) X-Gm-Message-State: AGi0PuaBIIbqtmKTULFVC7Hg6geHFygw6pm6YDOows8Skj4pFn/2dOF+ RQBsZz6SjGhXHj64eRpPm/5ykG5lIQ8fsmC7nAc= X-Google-Smtp-Source: APiQypK8zqZk5uLnoIubAdQeJgGTiVyPkpSzxxqDGQ7EZ4yy/nSPnZICKVDeK2bBxoQfBZJEyLjW+qUVp5bYDvV/ciM= X-Received: by 2002:a37:2714:: with SMTP id n20mr6302088qkn.138.1586178781557; Mon, 06 Apr 2020 06:13:01 -0700 (PDT) MIME-Version: 1.0 References: <20200406120312.1150405-1-hch@lst.de> <20200406120312.1150405-2-hch@lst.de> In-Reply-To: <20200406120312.1150405-2-hch@lst.de> From: Arnd Bergmann Date: Mon, 6 Apr 2020 15:12:45 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 1/6] powerpc/spufs: simplify spufs core dumping To: Christoph Hellwig Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:MVHMNJVbot1x+2RamT4BheYWQ4BV8svB9PbcfLCTJzAUPcti3F+ zaZ2074mRwwTlDFCod9SWB3z08TWFB0CZ3Sxzj+14EEYipIrufzu6j4gQLVjjIDCSzYSrZ4 zXmcrObI0cY36AW9YV7G1WewQX1YEpbqJ608rGpZk7XQD4YnpY7z6/tl3gk8pSnBczVo2ws BNRs3VI2fWEsRtFbM9UsA== X-UI-Out-Filterresults: notjunk:1;V03:K0:kVAC9ct4C8M=:e8V1jROxYphQEURklNLK3u UY1cErNbNZnoaGWJvY+bwGjz8wnEd5VDMwEldPw862QwCfX5IMz6DLCoCo90YQax+KDZzjWFk 1klAcc/3hl5w0JTT/UA1NsQkm+w/1DjCCyFkZtnIokzQ6SaRX0xC54r3vVlhNABSLaPgwISMl yTeyTV5LjVZ9IuKyUUeSk51xq+IklHEMUU0EDbgKtkegoHHCm3w0k8+sWCqAKBUkgOTae2vFi QhqnZPKCZv+5IELf/qPr9ErELrbE/eaJkHiTzvBwwPppjWJSKs8DTUvsTwJdiCn6tHslHmRws 6BlalfDjEy0PXqWPiPokhcdbRK34od0NZ1Qw5/6LEz2w9SeBspZmiGwcleTmTQn06TevwXYPU BZnZ3C4B+AeyTLu9Zj65fjh70mET9XfI0Ls+RjdpH9jiPVtT6vd7DHnbddOOWUarjCViXSpGv Odbb1tNdPiM5lH9coe7p70z8eWRxFcBr04WmFfO/LKeuj8vcC3XO1oEWSDhId6JTCzGgX5cif M8nriCv4ndeirKHeCrbsq92Wyy2FDAlqeNjmJoEFLxpQB1SydtbBMCjTjD2v6qRK8JhYbFzAj z2ZhIkJ7M+dWIv7wknMTsrXZTd7eWghphayZeHDgC5ndj3eqAVd6v29oBi4ZgOi8V+sbuI2WS +2bYNZdwgZxlqAi1pFk0t7tOxe8Ka2snMwrk1HW4c3STiL1Cl5TdFebZLlKFQwTAr6Ua3tYWi ffbBtC5JwImPNUwewJa1JFPLyXSOPqpyNn2J4/W4+XL6wMhljmaj2Uba1rjdrQxvXV/aT1eAR Vn5gODNyJh1FwLOfCTsRQNz7OQwWJzarLV1q7WGrIFrlXySFog= X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "linux-kernel@vger.kernel.org" , Alexander Viro , Linux FS-devel Mailing List , Andrew Morton , linuxppc-dev , Jeremy Kerr Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Apr 6, 2020 at 2:03 PM Christoph Hellwig wrote: > > Replace the coredump ->read method with a ->dump method that must call > dump_emit itself. That way we avoid a buffer allocation an messing with > set_fs() to call into code that is intended to deal with user buffers. > For the ->get case we can now use a small on-stack buffer and avoid > memory allocations as well. I had no memory of this code at all, but your change looks fine to me. Amazingly you even managed to even make it smaller and more readable Reviewed-by: Arnd Bergmann