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=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 65B49C433FF for ; Tue, 6 Aug 2019 00:46:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 301832147A for ; Tue, 6 Aug 2019 00:46:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=netronome-com.20150623.gappssmtp.com header.i=@netronome-com.20150623.gappssmtp.com header.b="gMySazlZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731137AbfHFAqq (ORCPT ); Mon, 5 Aug 2019 20:46:46 -0400 Received: from mail-qt1-f193.google.com ([209.85.160.193]:40998 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728483AbfHFAqq (ORCPT ); Mon, 5 Aug 2019 20:46:46 -0400 Received: by mail-qt1-f193.google.com with SMTP id d17so3971002qtj.8 for ; Mon, 05 Aug 2019 17:46:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :organization:mime-version:content-transfer-encoding; bh=p8EkPLfMAiHYzvY7/WHeWoOy2NzVK3krQJDIDAIgywc=; b=gMySazlZHEbNfuWW9hFvliEeRFIs1GtAopLb0fk3gG60CpC614Xv/q8S6YcfcqWjpf 6Dzr1OaT64dNc/z1rrf2vhD+JWUJKMfcXVcmTb475FjvWQs6mxQ7r2rLkj6JOLf89wt1 RR0C2hofkZdiF1+1DEjDtvIG5c+Go+itIaZlYRQhbOH3YJYp7I1Tgt7AKKa3aI0NreYU T3LW0h9AwK2X2DwlJIcIQFkGUOuVYhItomSF9JKz1ApVGb+HCilkp9gOctBmu0+BWyuC eYBr+0fxSNeb+bxzg1nPFPxr9vBcerY/0FqjCsZZ4mLab7gbI4BjX5Yyh0oRTRC5XXRi vJPg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:organization:mime-version:content-transfer-encoding; bh=p8EkPLfMAiHYzvY7/WHeWoOy2NzVK3krQJDIDAIgywc=; b=fcW2Q6VueCIJjKzi87frDDuZ/5czxp50V3YY+XGwQQvbtbhMFHr+3fQlxP+gKXX/CU SesqioC0jtcJOURYGbGwysRvUX+Og3wTmlA/RZiDxztXVCm6q5kEiJE9bAxv7trVbBVs Z7C+2AWPMfDdl5MTmRp4TR+5mxAxeDAC+VLnMWVm5hGgBGi9UV8drJZZGzQCRFdCRk2i u48Yk/Azzaar3LNpbOegptXd5rFVvgy01HePMkqBT06KVISOKUxKlQr0q5TF5HqRPLHw okTpVNUIb3HqZAIO1KveRaYxKzQ29L6r/Hfy1+53J8K6eeTXsvzDkRIQ80RQSaxl4ARu jcQA== X-Gm-Message-State: APjAAAXGmq9mXnRuKCxhSUkRBEMgAxvLGFqflghDxERurKMZNwDOGFSG I4eNInnNDljnE+XnDvCuE33dGA== X-Google-Smtp-Source: APXvYqyoKp7/WAVVsNNKyyEnGmtOchartOCs7vbZynHSvtZkvaxBgn5DxezlrO7b2Jfh5Zjk7y63XQ== X-Received: by 2002:ac8:43c5:: with SMTP id w5mr778262qtn.280.1565052405730; Mon, 05 Aug 2019 17:46:45 -0700 (PDT) Received: from cakuba.netronome.com ([66.60.152.14]) by smtp.gmail.com with ESMTPSA id m5sm35642248qke.25.2019.08.05.17.46.44 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Mon, 05 Aug 2019 17:46:45 -0700 (PDT) Date: Mon, 5 Aug 2019 17:46:18 -0700 From: Jakub Kicinski To: Jiangfeng Xiao Cc: , , , , , , , Subject: Re: [PATCH v1 1/3] net: hisilicon: make hip04_tx_reclaim non-reentrant Message-ID: <20190805174618.2b3b551a@cakuba.netronome.com> In-Reply-To: <1564835501-90257-2-git-send-email-xiaojiangfeng@huawei.com> References: <1564835501-90257-1-git-send-email-xiaojiangfeng@huawei.com> <1564835501-90257-2-git-send-email-xiaojiangfeng@huawei.com> Organization: Netronome Systems, Ltd. MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 3 Aug 2019 20:31:39 +0800, Jiangfeng Xiao wrote: > If hip04_tx_reclaim is interrupted while it is running > and then __napi_schedule continues to execute > hip04_rx_poll->hip04_tx_reclaim, reentrancy occurs > and oops is generated. So you need to mask the interrupt > during the hip04_tx_reclaim run. Napi poll method for the same napi instance can't be run concurrently. Could you explain a little more what happens here? Also looking at hip04_rx_poll() I don't think the interrupt re-enabling logic guarantees the interrupt is not armed when NAPI is scheduled. Please note that NAPI is no longer scheduled if napi_complete_done() returned false.