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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 C4024C433DB for ; Fri, 26 Mar 2021 13:50:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E047619F2 for ; Fri, 26 Mar 2021 13:50:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229951AbhCZNt1 (ORCPT ); Fri, 26 Mar 2021 09:49:27 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:27809 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230226AbhCZNtV (ORCPT ); Fri, 26 Mar 2021 09:49:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616766561; 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=wftucUMFQaOllmombeSNT//n1WKcSqJM+IZ/swXQYUo=; b=ZvQPfMZgnQ7ms/mxiGZ/3CtAD5atccgOC5WAXoh/iztj9oNUbUVVDVBz1PstdgAcd5v6uW ywxFVCsEFSh+4hLZsev/fIACwtofoo3XUCWrbDhlmBq9zk+TedlveexoPfuJRtrjJdEXw+ MaUAwwVs3XzM6SHfkoTeTD2v1+Vlvsk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-355-lziEHDBGP-CIEoy5rswQLQ-1; Fri, 26 Mar 2021 09:49:16 -0400 X-MC-Unique: lziEHDBGP-CIEoy5rswQLQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 270B796DD14; Fri, 26 Mar 2021 13:48:45 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.40.194.37]) by smtp.corp.redhat.com (Postfix) with SMTP id BB21A6062F; Fri, 26 Mar 2021 13:48:42 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Fri, 26 Mar 2021 14:48:44 +0100 (CET) Date: Fri, 26 Mar 2021 14:48:41 +0100 From: Oleg Nesterov To: Jens Axboe Cc: io-uring@vger.kernel.org, torvalds@linux-foundation.org, ebiederm@xmission.com, metze@samba.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/8] kernel: unmask SIGSTOP for IO threads Message-ID: <20210326134840.GA1290@redhat.com> References: <20210326003928.978750-1-axboe@kernel.dk> <20210326003928.978750-3-axboe@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210326003928.978750-3-axboe@kernel.dk> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Jens, sorry, I got lost :/ On 03/25, Jens Axboe wrote: > > With IO threads accepting signals, including SIGSTOP, where can I find this change? Looks like I wasn't cc'ed... > unmask the > SIGSTOP signal from the default blocked mask. > > Signed-off-by: Jens Axboe > --- > kernel/fork.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/fork.c b/kernel/fork.c > index d3171e8e88e5..d5a40552910f 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -2435,7 +2435,7 @@ struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node) > tsk = copy_process(NULL, 0, node, &args); > if (!IS_ERR(tsk)) { > sigfillset(&tsk->blocked); > - sigdelsetmask(&tsk->blocked, sigmask(SIGKILL)); > + sigdelsetmask(&tsk->blocked, sigmask(SIGKILL)|sigmask(SIGSTOP)); siginitsetinv(blocked, sigmask(SIGKILL)|sigmask(SIGSTOP)) but this is minor. To remind, either way this is racy and can't really help. And if "IO threads accepting signals" then I don't understand why. Sorry, I must have missed something. Oleg.