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=-5.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 70577C433E7 for ; Thu, 15 Oct 2020 14:32:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E718622256 for ; Thu, 15 Oct 2020 14:31:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AQMnVaxq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388354AbgJOOb7 (ORCPT ); Thu, 15 Oct 2020 10:31:59 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:49341 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387910AbgJOOb7 (ORCPT ); Thu, 15 Oct 2020 10:31:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602772318; 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=E7gZT/uq+bbgZGNzQ217HS7XAdR8J53BAoSax/kSLy4=; b=AQMnVaxqmYs06mGPb5fIKxAulv2YA/Y0QdJUU7vTEis8+vJVwCcwlN3sg+SLTmNQ5rbl6S ZyfCZsrfL/rU0XbSiMbgiOODsFsd72P7KvI8/DanQqdXUi3RblQIbeYBNGP3HFRHeDmlzb ZHXGP4h/Dhs2eTjbk8S2E+KFmZv9WLg= 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-333-FWJ9mjH8NVKEn0P7rLPMxw-1; Thu, 15 Oct 2020 10:31:56 -0400 X-MC-Unique: FWJ9mjH8NVKEn0P7rLPMxw-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 CBDDF80365E; Thu, 15 Oct 2020 14:31:54 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.40.193.8]) by smtp.corp.redhat.com (Postfix) with SMTP id 5BFBB76677; Thu, 15 Oct 2020 14:31:53 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Thu, 15 Oct 2020 16:31:54 +0200 (CEST) Date: Thu, 15 Oct 2020 16:31:52 +0200 From: Oleg Nesterov To: Jens Axboe Cc: linux-kernel@vger.kernel.org, io-uring@vger.kernel.org, peterz@infradead.org, tglx@linutronix.de Subject: Re: [PATCH 3/5] kernel: add support for TIF_NOTIFY_SIGNAL Message-ID: <20201015143151.GB24156@redhat.com> References: <20201015131701.511523-1-axboe@kernel.dk> <20201015131701.511523-4-axboe@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201015131701.511523-4-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 On 10/15, Jens Axboe wrote: > > static inline int signal_pending(struct task_struct *p) > { > +#if defined(CONFIG_GENERIC_ENTRY) && defined(TIF_NOTIFY_SIGNAL) > + /* > + * TIF_NOTIFY_SIGNAL isn't really a signal, but it requires the same > + * behavior in terms of ensuring that we break out of wait loops > + * so that notify signal callbacks can be processed. > + */ > + if (unlikely(test_tsk_thread_flag(p, TIF_NOTIFY_SIGNAL))) > + return 1; > +#endif > return task_sigpending(p); > } I don't understand why does this version requires CONFIG_GENERIC_ENTRY. Afaics, it is very easy to change all the non-x86 arches to support TIF_NOTIFY_SIGNAL, but it is not trivial to change them all to use kernel/entry/common.c ? Oleg.