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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1178CC433EF for ; Thu, 10 Feb 2022 15:49:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233962AbiBJPtx (ORCPT ); Thu, 10 Feb 2022 10:49:53 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:40394 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243757AbiBJPtx (ORCPT ); Thu, 10 Feb 2022 10:49:53 -0500 Received: from mail-ot1-x336.google.com (mail-ot1-x336.google.com [IPv6:2607:f8b0:4864:20::336]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E24BBAF for ; Thu, 10 Feb 2022 07:49:53 -0800 (PST) Received: by mail-ot1-x336.google.com with SMTP id d18-20020a9d51d2000000b005a09728a8c2so4087550oth.3 for ; Thu, 10 Feb 2022 07:49:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=WVkwfPNwg7xGaw1L9J03iZpsTdqxGmaiOrI0W3JdsPM=; b=XX9l2w5JUlgKIaugClVjh2gxxlkyqThr6eQoAfncCmmj5YGDfGXLoAFWuBk+qCk/fo 7QrdPd9gi8bQIx0gAulq3JNAn1heX1vyJz2fHLfjI96FPU7MRxzConvTOphI9UrpKF// DVbPpBrpyvL6OQBrhNbIci9zv056j0XwzNsum4OJYw6AcA1twRMQnxaxY0SMlkBXJvA0 cASdBPvup49hWKXlzRQkxgj8aTVFX6/vkFIXtcuW5RNOBBKfyW2QBqp1khXhghR/s66V U/ddZIe6Xj5Q5DITofE7tcGm8TSux0NzIIrfp4Jtv/EKvT3koaJU9ae+5KOjmTaMyMsF cAWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=WVkwfPNwg7xGaw1L9J03iZpsTdqxGmaiOrI0W3JdsPM=; b=pcdTUwu/PeLiwUZjbxIlAbdbZw3bZwexxp6wTz35UR+10qWuSQsHBpcYITeVeZmxIM dTBBTtCTigyJTVejBghD+vJtt+Oe0YIMdD/3lBvAiz38lkIVoKBWFkhsZKprjJromsiw GAqoNPo4ANYDxkoM/7pi7zttZwvzkRyi5frhpv6lRVxf4x2gFJlSELIGfgR/6MkyAmCj ZzYmaEMHITDnB7B8VWyNL8NWG05yzsbxzy9gM+wMhKdS2nXkVwg/NgHaNrw4G5ouQK4R 5+q78+rdNYgX+3teY2QznanJihPxGC6xNMJ/T7nMSyuD6H+i24MX/C6F1wesmhb/EYZH hUDQ== X-Gm-Message-State: AOAM5304iEGLdrxon/j+zs8VkaZIi82lBo5SA4WNcMNceb8ZMIMgpMZw N3hMSt5iZ/7A+sADxoEidXoCQSEj03Q= X-Google-Smtp-Source: ABdhPJyRspV9pIXPRKS0XnNJ5a23YSx9OVo3/HMiEnDfL46dUNakmPsPCxrWt3letPidW/G3eY/iiw== X-Received: by 2002:a05:6830:4420:: with SMTP id q32mr3107878otv.24.1644508191019; Thu, 10 Feb 2022 07:49:51 -0800 (PST) Received: from ?IPV6:2603:8081:140c:1a00:a322:3674:4a4a:9441? (2603-8081-140c-1a00-a322-3674-4a4a-9441.res6.spectrum.com. [2603:8081:140c:1a00:a322:3674:4a4a:9441]) by smtp.gmail.com with ESMTPSA id eh38sm3760747oab.36.2022.02.10.07.49.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 10 Feb 2022 07:49:50 -0800 (PST) Message-ID: Date: Thu, 10 Feb 2022 09:49:49 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH 2/3] RDMA/rxe: Replace write_lock_bh with write_lock_irqsave in __rxe_drop_index Content-Language: en-US To: Zhu Yanjun , Guoqing Jiang Cc: Jason Gunthorpe , RDMA mailing list References: <20220210073655.42281-1-guoqing.jiang@linux.dev> <20220210073655.42281-3-guoqing.jiang@linux.dev> From: Bob Pearson In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On 2/10/22 08:16, Zhu Yanjun wrote: > On Thu, Feb 10, 2022 at 3:37 PM Guoqing Jiang wrote: >> >> Same as __rxe_add_index, the lock need to be fully IRQ safe, otherwise >> below calltrace appears. >> I had the impression that NAPI ran on a soft IRQ and the rxe tasklets are also on soft IRQs. So at least in theory spin_lock_bh() should be sufficient. Can someone explain where the hard interrupt is coming from that we need to protect. There are other race conditions in current rxe that may also be the cause of this. I am trying to get a patch series accepted to deal with those. Bob