From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 61461A0524; Thu, 4 Feb 2021 13:53:43 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id CDF6324058E; Thu, 4 Feb 2021 13:53:42 +0100 (CET) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by mails.dpdk.org (Postfix) with ESMTP id 9314D240586 for ; Thu, 4 Feb 2021 13:53:41 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612443220; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oYp7P5WZIRvK8jISYcfs/VIFnzPyhRmr2UUcxDXpOPM=; b=bJBeJZ2nlvN2oaKJxlHpv1G5KLkMbgW74NLCl2g46vJz3MR2GW9N+mZ6bLI/QiTRq9kahP y6baVEwpibTlXJArJEV7reHKQHz5yQfwxxusIoInzcUoJpwj+08u51doS7H8LkWjrs2fKC poSfe5K6hBftSu/T5HAtT+vmV3OgaIY= Received: from mail-ua1-f71.google.com (mail-ua1-f71.google.com [209.85.222.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-319-p9FuROO3O0aj5ZAVuo7FiQ-1; Thu, 04 Feb 2021 07:53:38 -0500 X-MC-Unique: p9FuROO3O0aj5ZAVuo7FiQ-1 Received: by mail-ua1-f71.google.com with SMTP id d9so856879uaf.18 for ; Thu, 04 Feb 2021 04:53:38 -0800 (PST) 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:content-transfer-encoding; bh=oYp7P5WZIRvK8jISYcfs/VIFnzPyhRmr2UUcxDXpOPM=; b=Yd0jiSy8QreEGMpE4Q6G8GmuWulCdY8MMEj8bS1mdWooJjycD9VHxk1REbxUtFWAIX YIG45fIbSsh24AQpqN5MdxAtSR5QOS/XLWMB4vQ8KljgiZfPWpUjRfV7OEUA5M5LzUjr W8It1/rMpK0w9aOCileL+VIN04/gnIs0a3HU677itSKUvCY8O+HdfRIa/CmR711eeCcG JoZP5Y2lEF0rBu03Ikw7zB2UcgXXufJ9M9aq81LlmrlE0KhnkagKk9E5xe71OCnibKeN HqNkQiHrLRB+2b07t1QUeLy0xWja77NdTeoVCXb5eYQ2XcmNFFq804N7J66lc54AaE8I CNzg== X-Gm-Message-State: AOAM530sIu1GF1wAXAl2Z31iqmklUV+ihq0hmwcor2k3aLHyBsIslJrC UVhXXHne8qybqGM5ckoZqszL6oM6r9kTkwZVbnrz8/k8P26OHI1AFRBf0+9Yl3+WwUfdVWZYJsb CkICSb15cYzIDydhngsk= X-Received: by 2002:a1f:2b4d:: with SMTP id r74mr4751682vkr.17.1612443217653; Thu, 04 Feb 2021 04:53:37 -0800 (PST) X-Google-Smtp-Source: ABdhPJxrPenS2wAftsGijxqGeMRsvcyXVZwGC5WiB7OsJLnMu/Ultch3f5O59aoBQ4RWA582ls9LgzGJvJ4EOGYPOmo= X-Received: by 2002:a1f:2b4d:: with SMTP id r74mr4751677vkr.17.1612443217377; Thu, 04 Feb 2021 04:53:37 -0800 (PST) MIME-Version: 1.0 References: <20200826055233.26075-1-rohit.raj@nxp.com> <20201008153048.19369-1-rohit.raj@nxp.com> <20201008153048.19369-2-rohit.raj@nxp.com> <0c5203ec-2497-0be0-925a-834aa95fcc5a@huawei.com> In-Reply-To: <0c5203ec-2497-0be0-925a-834aa95fcc5a@huawei.com> From: David Marchand Date: Thu, 4 Feb 2021 13:53:26 +0100 Message-ID: To: oulijun Cc: dev Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dmarchan@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [dpdk-dev] [PATCH v4 2/5] examples/multi_process: cleanup bus objects while terminating app X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Mon, Jan 25, 2021 at 12:07 PM oulijun wrote: > >> +static void > >> +signal_handler(int signal) > >> +{ > >> + if (signal =3D=3D SIGINT) > >> + rte_eal_cleanup(); > >> + exit(0); > >> +} > > > > Calling rte_eal_cleanup from a signal handler is a bad idea. > > In most cases, you are racing with other threads still using DPDK resou= rces. > > https://git.dpdk.org/dpdk/commit?id=3D2c434431f4 > > https://git.dpdk.org/dpdk/commit?id=3D613ce6691c > > > > This might not be a problem in this multi_process example, but let's > > keep a consistent way across all examples. > > Thanks. > Hi=EF=BC=8C > I want to know why you don't think he's a problem. recently, we use > the patch > https://patchwork.dpdk.org/patch/86988/ > startup with multiprocess. Use the tester to send traffic and kill the > slave process repeatedly. > The coredump exception occurs. According to my analysis, the cause is > that resources are not released after the slave process is killed. > Not sure I get your question and I don't see the relation with the testpmd patch. I did not say we must not release resources. Just to rephrase my previous mail: Generally speaking, calling rte_eal_cleanup() from a signal handler is wrong since it creates races with other threads. I recommend putting in place a synchronisation mechanism so that all worker threads break out of their processing loop and the main thread synchronizes/joins with them before calling rte_eal_cleanup() in its exit path. Now, for this patch, in examples/multi_process/client_server_mp/mp_client/client.c, this secondary process code seems to only have one thread (but I might be wrong). If this is true, then no race in theory =3D> my comment "This might not be a problem in this multi_process example". --=20 David Marchand