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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 42112C433DF for ; Thu, 15 Oct 2020 14:54:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF5C121D7F for ; Thu, 15 Oct 2020 14:54:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="wSh6lUkY"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Cp/bi64b" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389442AbgJOOyX (ORCPT ); Thu, 15 Oct 2020 10:54:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32928 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388348AbgJOOyX (ORCPT ); Thu, 15 Oct 2020 10:54:23 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6FE74C061755; Thu, 15 Oct 2020 07:54:23 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1602773662; 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; bh=ubYf3uIUdQo/Q6bT+xRjgGp11qUFxlJTueT4HYtcveA=; b=wSh6lUkYEO1tc7RiI88tbavWABCiJVEC6E3Kw0RReu+RntJxLXRtEVIuyng5FIs0U6lQb2 P9VxdfdOeWxt/YhxzbdSFvdfSmEHiFcS5OHxcyEkIZOOT5psTnoGXzJTRC49HDRK57Ni0L RM1G/CroDEur8WHKZnsAbcI91/fIbjMweUGL2C/v4ldmTl+QXLMQo24Gd06EwC25LELvfb AEs8aaiti+tvYYGOBR1CYN7bgE/24HrmzmxskTVBy4ctSpJ0zybfxpHPeTFaR5+lrrqein xPok/m+ShBlgCitTumM2H4kSoHv+dq9i1umBO65QJuOYLlbhPfnDsdLk0SRofA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1602773662; 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; bh=ubYf3uIUdQo/Q6bT+xRjgGp11qUFxlJTueT4HYtcveA=; b=Cp/bi64bNNhdtVgNKP9ydTyMRMnC2HdODscc295c+nChqeID73hDstALv1QQGkMxiwfGTC OF27e7FgW7FIveAQ== To: Oleg Nesterov Cc: Jens Axboe , linux-kernel@vger.kernel.org, io-uring@vger.kernel.org, peterz@infradead.org Subject: Re: [PATCH 4/5] x86: wire up TIF_NOTIFY_SIGNAL In-Reply-To: <20201015143409.GC24156@redhat.com> Date: Thu, 15 Oct 2020 16:54:21 +0200 Message-ID: <87v9fbv8te.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 15 2020 at 16:34, Oleg Nesterov wrote: > On 10/15, Thomas Gleixner wrote: >> Instead of adding this to every architectures signal magic, we can >> handle TIF_NOTIFY_SIGNAL in the core code: >> >> static void handle_singal_work(ti_work, regs) >> { >> if (ti_work & _TIF_NOTIFY_SIGNAL) >> tracehook_notify_signal(); >> >> arch_do_signal(ti_work, regs); >> } >> >> loop { >> if (ti_work & (SIGPENDING | NOTIFY_SIGNAL)) >> handle_signal_work(ti_work, regs); >> } > > To me this looks like unnecessary complication. We need to change > every architecture anyway, how can this helper help? You need to change ONE architecture because nobody else uses the common entry loop right now. For those who move over they have to supply arch_do_signal() anyway, so the extra TIF check is not a problem. We really don't want all architectures to have the same thing copy&pasta'd. That's the whole point of common code to avoid that. Thanks, tglx