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 29CD9C43467 for ; Thu, 8 Oct 2020 12:58:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB5C7207DE for ; Thu, 8 Oct 2020 12:58:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="gsdm6G5I" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730161AbgJHM6m (ORCPT ); Thu, 8 Oct 2020 08:58:42 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:27778 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729722AbgJHM6m (ORCPT ); Thu, 8 Oct 2020 08:58:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602161921; 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=E/evyHUMI3fb2U+XwW2aLhJew6d+OCSc2FxwNfQU9Ew=; b=gsdm6G5IKhu4OWOIOEb3+Z00WguVw6Tm9UHJO8FVO352mtinXXw1ftgSqBp/ZUr9DLS6v0 JD3AhGW6P0lIONP6ejOpJpAGkyHMpNDZxAwnJqQKeNkXrhHzvCye+M/VlWlyKnPd1Y4NH/ EvqLAqPm0759nkEeuqqpHPGwDCRoj1I= 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-468-A4_CbhkhMPqT2czSDz7rHQ-1; Thu, 08 Oct 2020 08:58:36 -0400 X-MC-Unique: A4_CbhkhMPqT2czSDz7rHQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C5FFA10BBEC2; Thu, 8 Oct 2020 12:58:34 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.40.192.132]) by smtp.corp.redhat.com (Postfix) with SMTP id 54ABC6EF4A; Thu, 8 Oct 2020 12:58:33 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Thu, 8 Oct 2020 14:58:34 +0200 (CEST) Date: Thu, 8 Oct 2020 14:58:32 +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 2/6] kernel: add task_sigpending() helper Message-ID: <20201008125831.GE9995@redhat.com> References: <20201005150438.6628-1-axboe@kernel.dk> <20201005150438.6628-3-axboe@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201005150438.6628-3-axboe@kernel.dk> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 10/05, Jens Axboe wrote: > > static inline int signal_pending_state(long state, struct task_struct *p) > { > if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) > return 0; > - if (!signal_pending(p)) > + if (!task_sigpending(p)) > return 0; This looks obviously wrong. Say, schedule() in TASK_INTERRUPTIBLE should not block if TIF_NOTIFY_SIGNAL is set. With this change set_notify_signal() will not force the task to return from wait_event_interruptible, mutex_lock_interruptible, etc. > return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p); > @@ -389,7 +394,7 @@ static inline bool fault_signal_pending(vm_fault_t fault_flags, > { > return unlikely((fault_flags & VM_FAULT_RETRY) && > (fatal_signal_pending(current) || > - (user_mode(regs) && signal_pending(current)))); > + (user_mode(regs) && task_sigpending(current)))); This looks unnecessary, > @@ -773,7 +773,7 @@ static int ptrace_peek_siginfo(struct task_struct *child, > data += sizeof(siginfo_t); > i++; > > - if (signal_pending(current)) > + if (task_sigpending(current)) This too. IMO, this patch should do s/signal_pending/task_sigpending/ only if it is strictly needed for correctness. Oleg.