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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 4695FC43441 for ; Wed, 14 Nov 2018 17:36:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 10D5C22360 for ; Wed, 14 Nov 2018 17:36:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 10D5C22360 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731825AbeKODkU (ORCPT ); Wed, 14 Nov 2018 22:40:20 -0500 Received: from mx1.redhat.com ([209.132.183.28]:17811 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726883AbeKODkU (ORCPT ); Wed, 14 Nov 2018 22:40:20 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 98B0C8CC2; Wed, 14 Nov 2018 17:36:13 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.43.17.31]) by smtp.corp.redhat.com (Postfix) with SMTP id 3AC1760BF7; Wed, 14 Nov 2018 17:36:12 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 14 Nov 2018 18:36:13 +0100 (CET) Date: Wed, 14 Nov 2018 18:36:11 +0100 From: Oleg Nesterov To: Roman Gushchin Cc: Roman Gushchin , Tejun Heo , "cgroups@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Kernel Team Subject: Re: [PATCH v2 3/6] cgroup: cgroup v2 freezer Message-ID: <20181114173610.GF13885@redhat.com> References: <20181112230422.5911-1-guro@fb.com> <20181112230422.5911-5-guro@fb.com> <20181113154825.GC30990@redhat.com> <20181113215919.GC15590@tower.DHCP.thefacebook.com> <20181114165631.GE13885@redhat.com> <20181114170558.GA24889@castle.DHCP.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181114170558.GA24889@castle.DHCP.thefacebook.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Wed, 14 Nov 2018 17:36:13 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/14, Roman Gushchin wrote: > > > No, this is very wrong. Just suppose the caller is killed right before > > clear_thread_flag(TIF_SIGPENDING). > > So, I had TASK_KILLABLE before, but had some issues with ptrace/gdb. > I'll revisit this option. Yes, ptrace_signal_wake_up() won't wake a TASK_KILLABLE tracee up... BTW. Could you explain in the changelog how should a frozen task interact with ptrace? 0/6 says "ptrace works" but that is all. It is not clear to me what do we actually want wrt ptrace... Oleg.