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=-2.5 required=3.0 tests=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 6B264C433DF for ; Wed, 24 Jun 2020 03:41:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3F74F20857 for ; Wed, 24 Jun 2020 03:41:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388794AbgFXDlY (ORCPT ); Tue, 23 Jun 2020 23:41:24 -0400 Received: from mail.loongson.cn ([114.242.206.163]:45244 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388519AbgFXDlY (ORCPT ); Tue, 23 Jun 2020 23:41:24 -0400 Received: from [10.130.0.66] (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Ax9ulby_JeVBBJAA--.524S3; Wed, 24 Jun 2020 11:41:16 +0800 (CST) Subject: Re: [PATCH RESEND] net/cisco: Fix a sleep-in-atomic-context bug in enic_init_affinity_hint() To: David Miller References: <20200623.143311.995885759487352025.davem@davemloft.net> <20200623.152626.2206118203643133195.davem@davemloft.net> <7533075e-0e8e-2fde-c8fa-72e2ea222176@loongson.cn> <20200623.202324.442008830004872069.davem@davemloft.net> Cc: benve@cisco.com, _govind@gmx.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, lixuefeng@loongson.cn, yangtiezhu@loongson.cn From: Kaige Li Message-ID: <70519029-1cfa-5fce-52f3-cfb13bf00f7d@loongson.cn> Date: Wed, 24 Jun 2020 11:41:14 +0800 User-Agent: Mozilla/5.0 (X11; Linux mips64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20200623.202324.442008830004872069.davem@davemloft.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-CM-TRANSID: AQAAf9Ax9ulby_JeVBBJAA--.524S3 X-Coremail-Antispam: 1UD129KBjvdXoW7Jry8Xr15Zw48JF15CF45Wrg_yoWDCrcE9F yj93s7G345Xr4UtwnrJws5ur4ktw10krW5Z3y5XFWY9wn5tFWUGF4DC342vF4xWFZ7Zr9F kwnaqF15Zr129jkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb4AFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8w A2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Cr0_ Gr1UM28EF7xvwVC2z280aVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E 2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r4j6F4UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvEwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lc7I2V7IY0VAS07AlzVAY IcxG8wCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14 v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkG c2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI 0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6rW3Jr0E3s1lIxAIcVC2z280aVAFwI0_Jr0_ Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUb0D73 UUUUU== X-CM-SenderInfo: 5olntxtjh6z05rqj20fqof0/ Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/24/2020 11:23 AM, David Miller wrote: > From: Kaige Li > Date: Wed, 24 Jun 2020 09:56:47 +0800 > >> On 06/24/2020 06:26 AM, David Miller wrote: >>> From: David Miller >>> Date: Tue, 23 Jun 2020 14:33:11 -0700 (PDT) >>> >>>> Calling a NIC driver open function from a context holding a spinlock >>>> is very much the real problem, so many operations have to sleep and >>>> in face that ->ndo_open() method is defined as being allowed to sleep >>>> and that's why the core networking never invokes it with spinlocks >>> ^^^^ >>> >>> I mean "without" of course. :-) >>> >>>> held. >> Did you mean that open function should be out of spinlock? If so, I >> will >> send V2 patch. > Yes, but only if that is safe. > > You have to analyze the locking done by this driver and fix it properly. > I anticipate it is not just a matter of changing where the spinlock > is held, you will have to rearchitect things a bit. Okay, I will careful analyze this question, and make a suitable patch in V2. Thank you.