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=-10.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=ham 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 23D05C4338F for ; Thu, 5 Aug 2021 11:14:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EFBDB610FF for ; Thu, 5 Aug 2021 11:14:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240921AbhHELOd (ORCPT ); Thu, 5 Aug 2021 07:14:33 -0400 Received: from out30-56.freemail.mail.aliyun.com ([115.124.30.56]:37496 "EHLO out30-56.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240826AbhHELOa (ORCPT ); Thu, 5 Aug 2021 07:14:30 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R941e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04420;MF=xianting.tian@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0Ui1z.hC_1628162053; Received: from B-LB6YLVDL-0141.local(mailfrom:xianting.tian@linux.alibaba.com fp:SMTPD_---0Ui1z.hC_1628162053) by smtp.aliyun-inc.com(127.0.0.1); Thu, 05 Aug 2021 19:14:13 +0800 Subject: Re: [PATCH v3 1/2] tty: hvc: pass DMA capable memory to put_chars() To: Jiri Slaby , gregkh@linuxfoundation.org, amit@kernel.org, arnd@arndb.de, osandov@fb.com Cc: linuxppc-dev@lists.ozlabs.org, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <20210804025453.93543-1-xianting.tian@linux.alibaba.com> <0f26a1c3-53e8-9282-69e8-8d81a9cafc59@kernel.org> From: Xianting Tian Message-ID: <202cf491-5cdd-999f-d556-a5ebd2b4e266@linux.alibaba.com> Date: Thu, 5 Aug 2021 19:14:13 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2021/8/5 下午4:09, Jiri Slaby 写道: > On 05. 08. 21, 9:58, Jiri Slaby wrote: >> Hi, >> >> On 04. 08. 21, 4:54, Xianting Tian wrote: >>> @@ -933,6 +949,16 @@ struct hvc_struct *hvc_alloc(uint32_t vtermno, >>> int data, >>>       hp->outbuf_size = outbuf_size; >>>       hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))]; > > This deserves cleanup too. Why is "outbuf" not "char outbuf[0] > __ALIGNED__" at the end of the structure? The allocation would be > easier (using struct_size()) and this line would be gone completely. I will make the cleanup in v4. > >>> +    /* >>> +     * hvc_con_outbuf is guaranteed to be aligned at least to the >>> +     * size(N_OUTBUF) by kmalloc(). >>> +     */ >>> +    hp->hvc_con_outbuf = kzalloc(N_OUTBUF, GFP_KERNEL); >>> +    if (!hp->hvc_con_outbuf) >>> +        return ERR_PTR(-ENOMEM); >> >> This leaks hp, right? > > Actually, why don't you make > char c[N_OUTBUF] __ALIGNED__; > > part of struct hvc_struct directly? thanks, it a good idea, I will change it in v4. > >> BTW your 2 patches are still not threaded, that is hard to follow. >> >>> + >>> +    spin_lock_init(&hp->hvc_con_lock); >>> + >>>       tty_port_init(&hp->port); >>>       hp->port.ops = &hvc_port_ops; >> >> thanks, 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=-10.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=unavailable 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 2BDBFC4338F for ; Thu, 5 Aug 2021 11:14:55 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 83CE0610FF for ; Thu, 5 Aug 2021 11:14:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 83CE0610FF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4GgQxS46wJz3cM0 for ; Thu, 5 Aug 2021 21:14:52 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.alibaba.com (client-ip=47.88.44.36; helo=out4436.biz.mail.alibaba.com; envelope-from=xianting.tian@linux.alibaba.com; receiver=) Received: from out4436.biz.mail.alibaba.com (out4436.biz.mail.alibaba.com [47.88.44.36]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4GgQx60F1gz3cKv for ; Thu, 5 Aug 2021 21:14:32 +1000 (AEST) X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R941e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04420; MF=xianting.tian@linux.alibaba.com; NM=1; PH=DS; RN=8; SR=0; TI=SMTPD_---0Ui1z.hC_1628162053; Received: from B-LB6YLVDL-0141.local(mailfrom:xianting.tian@linux.alibaba.com fp:SMTPD_---0Ui1z.hC_1628162053) by smtp.aliyun-inc.com(127.0.0.1); Thu, 05 Aug 2021 19:14:13 +0800 Subject: Re: [PATCH v3 1/2] tty: hvc: pass DMA capable memory to put_chars() To: Jiri Slaby , gregkh@linuxfoundation.org, amit@kernel.org, arnd@arndb.de, osandov@fb.com References: <20210804025453.93543-1-xianting.tian@linux.alibaba.com> <0f26a1c3-53e8-9282-69e8-8d81a9cafc59@kernel.org> From: Xianting Tian Message-ID: <202cf491-5cdd-999f-d556-a5ebd2b4e266@linux.alibaba.com> Date: Thu, 5 Aug 2021 19:14:13 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 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: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" 在 2021/8/5 下午4:09, Jiri Slaby 写道: > On 05. 08. 21, 9:58, Jiri Slaby wrote: >> Hi, >> >> On 04. 08. 21, 4:54, Xianting Tian wrote: >>> @@ -933,6 +949,16 @@ struct hvc_struct *hvc_alloc(uint32_t vtermno, >>> int data, >>>       hp->outbuf_size = outbuf_size; >>>       hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))]; > > This deserves cleanup too. Why is "outbuf" not "char outbuf[0] > __ALIGNED__" at the end of the structure? The allocation would be > easier (using struct_size()) and this line would be gone completely. I will make the cleanup in v4. > >>> +    /* >>> +     * hvc_con_outbuf is guaranteed to be aligned at least to the >>> +     * size(N_OUTBUF) by kmalloc(). >>> +     */ >>> +    hp->hvc_con_outbuf = kzalloc(N_OUTBUF, GFP_KERNEL); >>> +    if (!hp->hvc_con_outbuf) >>> +        return ERR_PTR(-ENOMEM); >> >> This leaks hp, right? > > Actually, why don't you make > char c[N_OUTBUF] __ALIGNED__; > > part of struct hvc_struct directly? thanks, it a good idea, I will change it in v4. > >> BTW your 2 patches are still not threaded, that is hard to follow. >> >>> + >>> +    spin_lock_init(&hp->hvc_con_lock); >>> + >>>       tty_port_init(&hp->port); >>>       hp->port.ops = &hvc_port_ops; >> >> thanks,