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[23.128.96.18]) by mx.google.com with ESMTP id c4si1006600edw.41.2020.09.02.22.03.32; Wed, 02 Sep 2020 22:04:12 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=nMzVYFt6; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726331AbgICFBc (ORCPT + 99 others); Thu, 3 Sep 2020 01:01:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725851AbgICFBb (ORCPT ); Thu, 3 Sep 2020 01:01:31 -0400 Received: from mail-io1-xd31.google.com (mail-io1-xd31.google.com [IPv6:2607:f8b0:4864:20::d31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01BD4C061244; Wed, 2 Sep 2020 22:01:31 -0700 (PDT) Received: by mail-io1-xd31.google.com with SMTP id z25so1341121iol.10; Wed, 02 Sep 2020 22:01:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=VhropMQESNSMSxgIqr1ZDerfNQ9kD0plBvpn1qDMszM=; b=nMzVYFt6wL+sFTiIRt+EX4YPgpv0eQNE7JufaNot1Lr+3QgrM7JZ/voUg/qQ7UbL+p DQFGu5umpYZ+THfWnkJ4mXU4H4h7jITCMmeZ+hS79U8+8OwI8Z5TRXx+hMbyzC4DHb/K 5aNKWNw8+2M6tDNSwADL1VeJDZOaPykT8EDJepafKstZiG2xtkhfmmcVB69wrouZM7ZY 5am1zK3eAt82Pih+91tSc63Z+VPnOGgGbmATRryeJT17ziZG0VYHgrEabiSxD9JssVNQ AFY4pFaMCvYNN1+VSpco4qt67qf/LmkFhAMXS5CLyISWgtFm7KnJu/gzO59tJ1a0ci0F HsFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=VhropMQESNSMSxgIqr1ZDerfNQ9kD0plBvpn1qDMszM=; b=EbZ1jR0O475+3q6f1kCMg0ffByXo5jPjBPD45u8/INxBzOaSJfeu9YyBl+d8XDyxcW mt6ZLQfo73mIJ+7CBZzk1bR/3UA0m+6GwIfdnYGFD1RuBFsnW50f+EmXf5hlhSFDtk++ TgKfBeuVTsU6qu+jqMKLTH0aGa/tF51jKciWGgXttqUBUaffc8ISObOUr5z6SQUxDjRu xLGGnjmq5pHtV5uwh1y4bmu1I+Uz4g1cYhL6ZeLhf0R9uQ9sGCzkHWFUbfso+E4TU+NY zrqlmcQ6XoK02zhS4UfxLTuvGQfihXy2e02YGWmrFI4ihkSFFKf+OpEoYHMlN8SjJaH+ D+cQ== X-Gm-Message-State: AOAM532QkEvUJOvBTa1LDoiewRCOJXWxRtOHeHYnKJfPZ5rEyTg8xgUY +6z/Sr56In1s5NmF3SD9Rbey1v9/oqh2vCL1RPs= X-Received: by 2002:a05:6602:1589:: with SMTP id e9mr1576006iow.85.1599109289807; Wed, 02 Sep 2020 22:01:29 -0700 (PDT) MIME-Version: 1.0 References: <465a540e-5296-32e7-f6a6-79942dfe2618@netrounds.com> <20200623134259.8197-1-mzhivich@akamai.com> <1849b74f-163c-8cfa-baa5-f653159fefd4@akamai.com> <7fd86d97-6785-0b5f-1e95-92bc1da9df35@netrounds.com> <500b4843cb7c425ea5449fe199095edd5f7feb0c.camel@redhat.com> <25ca46e4-a8c1-1c88-d6a9-603289ff44c3@akamai.com> <20200822032800.16296-1-hdanton@sina.com> <20200825032312.11776-1-hdanton@sina.com> <20200825162329.11292-1-hdanton@sina.com> <5f46032e.1c69fb81.9880c.7a6cSMTPIN_ADDED_MISSING@mx.google.com> <20200827125747.5816-1-hdanton@sina.com> In-Reply-To: From: Cong Wang Date: Wed, 2 Sep 2020 22:01:17 -0700 Message-ID: Subject: Re: Packet gets stuck in NOLOCK pfifo_fast qdisc To: Kehuan Feng Cc: Hillf Danton , Jike Song , Josh Hunt , Paolo Abeni , Jonas Bonn , Michael Zhivich , David Miller , John Fastabend , LKML , Netdev Content-Type: multipart/mixed; boundary="0000000000002d36f305ae61a588" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --0000000000002d36f305ae61a588 Content-Type: text/plain; charset="UTF-8" Hello, Kehuan Can you test the attached one-line fix? I think we are overthinking, probably all we need here is a busy wait. Thanks. --0000000000002d36f305ae61a588 Content-Type: text/x-patch; charset="US-ASCII"; name="qdisc-seqlock.diff" Content-Disposition: attachment; filename="qdisc-seqlock.diff" Content-Transfer-Encoding: base64 Content-ID: X-Attachment-Id: f_kemc7lqb0 ZGlmZiAtLWdpdCBhL2luY2x1ZGUvbmV0L3NjaF9nZW5lcmljLmggYi9pbmNsdWRlL25ldC9zY2hf Z2VuZXJpYy5oCmluZGV4IGQ2MGU3YzM5ZDYwYy4uZmMxYmFjZGIxMDJiIDEwMDY0NAotLS0gYS9p bmNsdWRlL25ldC9zY2hfZ2VuZXJpYy5oCisrKyBiL2luY2x1ZGUvbmV0L3NjaF9nZW5lcmljLmgK QEAgLTE1Niw4ICsxNTYsNyBAQCBzdGF0aWMgaW5saW5lIGJvb2wgcWRpc2NfaXNfZW1wdHkoY29u c3Qgc3RydWN0IFFkaXNjICpxZGlzYykKIHN0YXRpYyBpbmxpbmUgYm9vbCBxZGlzY19ydW5fYmVn aW4oc3RydWN0IFFkaXNjICpxZGlzYykKIHsKIAlpZiAocWRpc2MtPmZsYWdzICYgVENRX0ZfTk9M T0NLKSB7Ci0JCWlmICghc3Bpbl90cnlsb2NrKCZxZGlzYy0+c2VxbG9jaykpCi0JCQlyZXR1cm4g ZmFsc2U7CisJCXNwaW5fbG9jaygmcWRpc2MtPnNlcWxvY2spOwogCQlXUklURV9PTkNFKHFkaXNj LT5lbXB0eSwgZmFsc2UpOwogCX0gZWxzZSBpZiAocWRpc2NfaXNfcnVubmluZyhxZGlzYykpIHsK IAkJcmV0dXJuIGZhbHNlOwo= --0000000000002d36f305ae61a588--