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 8F16AC433DF for ; Thu, 15 Oct 2020 15:27:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 39A5F2225D for ; Thu, 15 Oct 2020 15:27:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Cf0JTtnj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389250AbgJOP1P (ORCPT ); Thu, 15 Oct 2020 11:27:15 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:44858 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389226AbgJOP1P (ORCPT ); Thu, 15 Oct 2020 11:27:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602775634; 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=TG2AUrfxhLY/L3sbUtf1bcZcGZTtMmaOPuFCfyv4d/g=; b=Cf0JTtnjRX/JUNdJ3m/MXzpk7AXLnnq8FTTBxci+s6YcP8EmS9lHrl8sW65cgEYISjrVn7 DIUFFDCCHEHibx265KsiSJvY0Sf+gyQmknZWF986Uv1nKGohu/4eNsSOsr7tkXvFnOFPOU 5RorA3i+mwLnbYx70w+BIiU+vGrSpdY= 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-499-OmhcBhRnMLCAHN0wX7eWAg-1; Thu, 15 Oct 2020 11:27:12 -0400 X-MC-Unique: OmhcBhRnMLCAHN0wX7eWAg-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 E74451084D85; Thu, 15 Oct 2020 15:27:10 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.40.193.8]) by smtp.corp.redhat.com (Postfix) with SMTP id 7D43C6EF54; Thu, 15 Oct 2020 15:27:09 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Thu, 15 Oct 2020 17:27:10 +0200 (CEST) Date: Thu, 15 Oct 2020 17:27:08 +0200 From: Oleg Nesterov To: Thomas Gleixner Cc: Jens Axboe , linux-kernel@vger.kernel.org, io-uring@vger.kernel.org, peterz@infradead.org Subject: Re: [PATCH 3/5] kernel: add support for TIF_NOTIFY_SIGNAL Message-ID: <20201015152707.GL24156@redhat.com> References: <20201015131701.511523-1-axboe@kernel.dk> <20201015131701.511523-4-axboe@kernel.dk> <20201015143151.GB24156@redhat.com> <5d231aa1-b8c7-ae4e-90bb-211f82b57547@kernel.dk> <20201015143728.GE24156@redhat.com> <87r1pzv8hy.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87r1pzv8hy.fsf@nanos.tec.linutronix.de> 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 10/15, Thomas Gleixner wrote: > > On Thu, Oct 15 2020 at 16:37, Oleg Nesterov wrote: > > On 10/15, Jens Axboe wrote: > >> On 10/15/20 8:31 AM, Oleg Nesterov wrote: > >> > 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 ? > >> > >> I think that Thomas wants to gate TIF_NOTIFY_SIGNAL on conversion to > >> the generic entry code? > > > > Then I think TIF_NOTIFY_SIGNAL will be never fully supported ;) > > Yeah, we proliferate crap on that basis forever. _ALL_ architectures > have the very same entry/exit ordering problems (or subsets and > different ones) which we fixed on x86. > > So no, we don't want to have 24 different variants of the same thing > again. That's what common code is for. > > Not doing that is making the life of everyone working on core > infrastructure pointlessly harder. Architecture people still have enough > ways to screw everyone up. Sure, it would be nice to change them all to use kernel/entry/common.c. Until then (until never), how can we kill JOBCTL_TASK_WORK ? How can we remove freezing/klp_patch_pending from recalc_sigpending() ? Oleg.