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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E372C77B7D for ; Thu, 18 May 2023 16:27:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229825AbjERQ1I (ORCPT ); Thu, 18 May 2023 12:27:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229601AbjERQ07 (ORCPT ); Thu, 18 May 2023 12:26:59 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ACF87B3 for ; Thu, 18 May 2023 09:26:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684427171; 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: in-reply-to:in-reply-to:references:references; bh=N0VBaOKRYTVXJE7z+8gKbNWq3wyr8YL28adwGI5M+8Q=; b=DCORfyWOWZTH4RUdQkYEotrbDaBDq7rmrung2Il2lcqgbVhprM9KfA50kpxNsE/MWdKpcr ua7nQYShRBddGbZvgbJVDqKupq3fSK2rPxgB5eFzrPnoslVenEU5VBehEF2WfO2RGgv/hu b0Z5QD1xUtHl2eZt+Ed1cJGdn/7nXOc= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-499-xlcIGl63Ncy0qqjYJ0vFaw-1; Thu, 18 May 2023 12:26:07 -0400 X-MC-Unique: xlcIGl63Ncy0qqjYJ0vFaw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2E18C805F58; Thu, 18 May 2023 16:26:07 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.20]) by smtp.corp.redhat.com (Postfix) with SMTP id 4D4651121314; Thu, 18 May 2023 16:26:04 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Thu, 18 May 2023 18:25:52 +0200 (CEST) Date: Thu, 18 May 2023 18:25:49 +0200 From: Oleg Nesterov To: Mike Christie Cc: "Eric W. Biederman" , linux@leemhuis.info, nicolas.dichtel@6wind.com, axboe@kernel.dk, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, mst@redhat.com, sgarzare@redhat.com, jasowang@redhat.com, stefanha@redhat.com, brauner@kernel.org Subject: Re: [RFC PATCH 1/8] signal: Dequeue SIGKILL even if SIGNAL_GROUP_EXIT/group_exec_task is set Message-ID: <20230518162508.GB20779@redhat.com> References: <20230518000920.191583-1-michael.christie@oracle.com> <20230518000920.191583-2-michael.christie@oracle.com> <87ednei9is.fsf@email.froward.int.ebiederm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I too do not understand the 1st change in this patch ... On 05/18, Mike Christie wrote: > > In the other patches we do: > > if (get_signal(ksig)) > start_exit_cleanup_by_stopping_newIO() > flush running IO() > exit() > > But to do the flush running IO() part of this I need to wait for it so > that's why I wanted to be able to dequeue the SIGKILL and clear the > TIF_SIGPENDING bit. But get_signal() will do what you need, dequeue SIGKILL and clear SIGPENDING ? if ((signal->flags & SIGNAL_GROUP_EXIT) || signal->group_exec_task) { clear_siginfo(&ksig->info); ksig->info.si_signo = signr = SIGKILL; sigdelset(¤t->pending.signal, SIGKILL); this "dequeues" SIGKILL, trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO, &sighand->action[SIGKILL - 1]); recalc_sigpending(); this clears TIF_SIGPENDING. > Or I don't need this specifically. In patch 0/8 I said I knew you guys > would not like it :) If I just have a: > > if (fatal_signal()) > clear_fatal_signal() see above... Well... I think this code is actually wrong if if SIGSTOP is pending and the task is PF_IO_WORKER, but this is also true for io-threads so we can discuss this separately. Oleg.