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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83D3AC433EF for ; Wed, 2 Mar 2022 21:52:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EAC1B8D0002; Wed, 2 Mar 2022 16:52:22 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E5B858D0001; Wed, 2 Mar 2022 16:52:22 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D24C78D0002; Wed, 2 Mar 2022 16:52:22 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id C46CC8D0001 for ; Wed, 2 Mar 2022 16:52:22 -0500 (EST) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 83F091F50 for ; Wed, 2 Mar 2022 21:52:22 +0000 (UTC) X-FDA: 79200795324.15.70BAD15 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf29.hostedemail.com (Postfix) with ESMTP id 14E71120002 for ; Wed, 2 Mar 2022 21:52:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=TTmCl82JqLan3QsNgtCR8eCTt45Umy9DiqQwuLlp+nY=; b=KfoYwSU15wZdPny08l3cV8PBZu suXZGirPexQrDgbQX5uGJbU7Df1yJ1ktmLv0jS0sAZKNx+pJdixfgD4R/TDEPqhbqI3BfNt42pheu RjmWCL0DlPB+78SrZXIMGba7JmRb0PQyQQUHkbneh6Acx7Xd1qd6fXDaMXTTVqKiOH3qxy3tAQDOa GvCaN0q6n5SXSqbjf6rmf5n5+sqFBgieDDlbNUI+aO5wXsxAJTiY1flBdSrbSaeah/4c62cT3Q8Hb UXbPO8ixKuUhGo/2c7lCT4NM75T9VeG9xmm8CWBJ8Utbrwowego6iSKFJmRdAIxORzhTRN/ip1tN8 MLIdp1Fg==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nPWt7-004R35-C3; Wed, 02 Mar 2022 21:52:01 +0000 Date: Wed, 2 Mar 2022 13:52:01 -0800 From: Luis Chamberlain To: "Eric W. Biederman" Cc: Shakeel Butt , Colin Ian King , NeilBrown , Vasily Averin , Vlastimil Babka , Michal Hocko , Roman Gushchin , Linux MM , netdev@vger.kernel.org, "David S. Miller" , Jakub Kicinski , Tejun Heo , Greg Kroah-Hartman , Eric Dumazet , Kees Cook , Hideaki YOSHIFUJI , David Ahern , linux-kernel@vger.kernel.org, kernel@openvz.org Subject: Re: [PATCH RFC] net: memcg accounting for veth devices Message-ID: References: <20220301180917.tkibx7zpcz2faoxy@google.com> <87wnhdwg75.fsf@email.froward.int.ebiederm.org> <87ilswwh1x.fsf@email.froward.int.ebiederm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87ilswwh1x.fsf@email.froward.int.ebiederm.org> X-Rspamd-Queue-Id: 14E71120002 X-Stat-Signature: tx3fisuu5ubf1okcb74x4tqrehcbmcnh X-Rspam-User: Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=KfoYwSU1; spf=none (imf29.hostedemail.com: domain of mcgrof@infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=mcgrof@infradead.org; dmarc=fail reason="No valid SPF, DKIM not aligned (relaxed)" header.from=kernel.org (policy=none) X-Rspamd-Server: rspam07 X-HE-Tag: 1646257941-915070 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Mar 02, 2022 at 08:43:54AM -0600, Eric W. Biederman wrote: > Luis Chamberlain writes: > > > On Tue, Mar 01, 2022 at 02:50:06PM -0600, Eric W. Biederman wrote: > >> I really have not looked at this pids controller. > >> > >> So I am not certain I understand your example here but I hope I have > >> answered your question. > > > > During experimentation with the above stress-ng test case, I saw tons > > of thread just waiting to do exit: > > You increment the count of concurrent threads after a no return function > in do_exit. Since the increment is never reached the count always goes > down and eventually the warning prints. > > > diff --git a/kernel/exit.c b/kernel/exit.c > > index 80c4a67d2770..653ca7ebfb58 100644 > > --- a/kernel/exit.c > > +++ b/kernel/exit.c > > @@ -881,6 +894,9 @@ void __noreturn do_exit(long code) > > > > lockdep_free_task(tsk); > > do_task_dead(); > > The function do_task_dead never returns. > > > + > > + atomic_inc(&exit_concurrent_max); > > + wake_up(&exit_wq); > > } > > EXPORT_SYMBOL_GPL(do_exit); Doh thanks! Luis