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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 C8E98C7618B for ; Fri, 26 Jul 2019 17:07:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 98441218D4 for ; Fri, 26 Jul 2019 17:07:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="NCCJAR+Z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728176AbfGZRHc (ORCPT ); Fri, 26 Jul 2019 13:07:32 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:36139 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728117AbfGZRHc (ORCPT ); Fri, 26 Jul 2019 13:07:32 -0400 Received: by mail-pf1-f196.google.com with SMTP id r7so24810300pfl.3 for ; Fri, 26 Jul 2019 10:07:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=bS9fLvgPfVAg2OSCXOIsqMJpT25qiH0bC1jmAoaZ02w=; b=NCCJAR+Za7x3HaI8H5CFemHhLHGi3ev3MyV5WZl6zAmaxI8OUei868E/4fIbbi8NYf JVsMGzQbOfELxLHWUyNslJINjJvSI23zCdoPTHtmWiwKPX8rmLbwreOy023i8Uerom1w pHcYS8RdoXLSF16XXrQIP91pHB3W5r3YHZh9Y= 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:references :mime-version:content-disposition:in-reply-to:user-agent; bh=bS9fLvgPfVAg2OSCXOIsqMJpT25qiH0bC1jmAoaZ02w=; b=cMLKypqRtNZ3ZuIwvKfIi9xx3X6bsVLtQ140FCqlDEHYlo/YmdUDmd1FHhSIj0nbBH /jnIfuvV9J66fyV5kFMm6v3XBpgVt04um73aM2+xm4a5MAsPO/BIgO0aSIdufq0rj23T XrZte/7OcQU8Zxlx1f5gr2NSaqyfYGWVr1ApsFWrVxlAcEcMydEVu0obVLfno/cTgnkn nazNgQSeuHE8oPay0N7MXe1mw9be3gK26V8c0Gt9an403k3D/5Mvo8PYLAyvQX+YYUCd H+mVncKX2IqGtnlJ8hgOhUH9FG1akfv1ZW/2SBX2vMyrjT80cXI7X2QPavDelg9KxdDo PhUg== X-Gm-Message-State: APjAAAWVCDvnbXOzuxcyf13IJPcT9kJYvcddhBSI2wVElC+jxy1A7YC7 vOvVue1P8g/AVFoyEBWAMsE= X-Google-Smtp-Source: APXvYqx+mjnUeYOhiUHp2OSWra7c9gbT97jFl03WbbuCc21u9SPLAOw/T91dX4uBmrKfQ4lkwCj2og== X-Received: by 2002:a17:90a:3225:: with SMTP id k34mr97679092pjb.31.1564160851038; Fri, 26 Jul 2019 10:07:31 -0700 (PDT) Received: from localhost ([2620:15c:6:12:9c46:e0da:efbf:69cc]) by smtp.gmail.com with ESMTPSA id c130sm51664784pfc.184.2019.07.26.10.07.29 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Fri, 26 Jul 2019 10:07:30 -0700 (PDT) Date: Fri, 26 Jul 2019 13:07:28 -0400 From: Joel Fernandes To: Suren Baghdasaryan Cc: christian@brauner.io, arnd@arndb.de, ebiederm@xmission.com, keescook@chromium.org, dancol@google.com, tglx@linutronix.de, jannh@google.com, dhowells@redhat.com, mtk.manpages@gmail.com, luto@kernel.org, akpm@linux-foundation.org, oleg@redhat.com, cyphar@cyphar.com, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, linux-api@vger.kernel.org, linux-kselftest@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH v3 2/2] tests: add pidfd poll tests Message-ID: <20190726170728.GA157922@google.com> References: <20190726162226.252750-1-surenb@google.com> <20190726162226.252750-2-surenb@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190726162226.252750-2-surenb@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Fri, Jul 26, 2019 at 09:22:26AM -0700, Suren Baghdasaryan wrote: > This adds testing for polling on pidfd of a process being killed. Test runs > 10000 iterations by default to stress test pidfd polling functionality. > It accepts an optional command-line parameter to override the number or > iterations to run. > Specifically, it tests for: > - pidfd_open on a child process succeeds > - pidfd_send_signal on a child process succeeds > - polling on pidfd succeeds and returns exactly one event > - returned event is POLLIN > - event is received within 3 secs of the process being killed > > 10000 iterations was chosen because of the race condition being tested > which is not consistently reproducible but usually is revealed after less > than 2000 iterations. > Reveals race fixed by commit b191d6491be6 ("pidfd: fix a poll race when setting exit_state") > > Signed-off-by: Suren Baghdasaryan > --- > + close(pidfd); > + // Wait for child to prevent zombies Comment style should be /* */, but I think Christian would be kind enough to fix that when he applies the patch so shouldn't need a resend. Thanks Suren and Christian! Reviewed-by: Joel Fernandes (Google)