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=-6.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A6A4CC43457 for ; Thu, 15 Oct 2020 14:56:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4753722256 for ; Thu, 15 Oct 2020 14:56:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="sSAfg4AY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388856AbgJOO4U (ORCPT ); Thu, 15 Oct 2020 10:56:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33230 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388086AbgJOO4U (ORCPT ); Thu, 15 Oct 2020 10:56:20 -0400 Received: from mail-io1-xd42.google.com (mail-io1-xd42.google.com [IPv6:2607:f8b0:4864:20::d42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C2FDC0613D2 for ; Thu, 15 Oct 2020 07:56:19 -0700 (PDT) Received: by mail-io1-xd42.google.com with SMTP id k6so4861523ior.2 for ; Thu, 15 Oct 2020 07:56:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=AURqElLapXfIq1JtkqDTZMuELCauu1vdJG7L6jXFcKU=; b=sSAfg4AYXOFZCFNYkNGm/lC1+de9uqy6ujB1GXTiKPsKVpnnTn752c9RUNwQDjDHrp O8BLjxEcibfhIIfYkZQo4ldOTIj/h86z4FutmZFEgIffQWKBu89vxh97D1x4AcI3DDQd Na9zYkoO8NriBao2qi32kZqT7zEHcKyx3E2ioKuyvWGXelLR9sa+r0GWbPjKVkkpIR5q D93orduTmYKPin9VlxHtWkt6r8lBf7tb1Lj1X82u3EvwNJ2be7x9LVCEytVKt++xFwyH USjsqn0N1vAiEr8Si6VRCPi/Ya+gAWiiKLb9bo8QRwYUeHCBLtdhaTPr46SRxOZ2OSp+ p6NA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=AURqElLapXfIq1JtkqDTZMuELCauu1vdJG7L6jXFcKU=; b=bKyiKQabMv+P/xFwsuDuE7a/ucXSRx84xhhUBUZes1M7pnORIwhHziD6uGcq2AIpJW KEKnjrEIFeN6F8rbLd33KrdHPchupFBZWjpHaShFe1uOSSnM3NIhAsTKtkbQ8W25NcyM 1vbdFocCoeUn0Gk44fd55pkK/9gEReyiwD4jFvsXPHHD3IrI0kMYHfIUV6YnMrTVDI0q EzAgaHkjRQa7ZG9zIf2G8yAO+l6r7vVbHWetW3XwcuveCnBPsftloeAE1aHMb1F/iRhD 8BcvnSweP3Bb6hTzotN/MYrtYIS1q+aXVA6Vf0xElADk2K/KGl+Co4DbHblvkzBPTwz+ wnNQ== X-Gm-Message-State: AOAM531DTujCo9aGIIaTSb2ZZTvhU1T86KVIvUHa4w8ebzuhxK2DwW+t jgF074KzKfdUUWRUqTaIGV44TCDw8VgBtg== X-Google-Smtp-Source: ABdhPJzLp0ghQwKMj3fGnZqXE6trkU/wVwv6YXUokKAxI5FjspONir29jz521ZzOGC4e6ntSzCdKeg== X-Received: by 2002:a6b:fc18:: with SMTP id r24mr3523381ioh.127.1602773778903; Thu, 15 Oct 2020 07:56:18 -0700 (PDT) Received: from [192.168.1.30] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id y8sm2751899ilq.2.2020.10.15.07.56.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 15 Oct 2020 07:56:18 -0700 (PDT) Subject: Re: [PATCH 3/5] kernel: add support for TIF_NOTIFY_SIGNAL To: Oleg Nesterov Cc: linux-kernel@vger.kernel.org, io-uring@vger.kernel.org, peterz@infradead.org, tglx@linutronix.de 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> <788b31b7-6acc-cc85-5e91-d0c2538341b7@kernel.dk> <20201015144713.GJ24156@redhat.com> <20201015145359.GA14671@redhat.com> From: Jens Axboe Message-ID: Date: Thu, 15 Oct 2020 08:56:17 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201015145359.GA14671@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 10/15/20 8:53 AM, Oleg Nesterov wrote: > On 10/15, Oleg Nesterov wrote: >> >> On 10/15, Jens Axboe wrote: >>> >>> That is indeed a worry. From a functionality point of view, with the >>> major archs supporting it, I'm not too worried about that side. But it >>> does mean that we'll be stuck with the ifdeffery forever, which isn't >>> great. >> >> plus we can't kill the ugly JOBCTL_TASK_WORK. > > not to mention we can not change freezer/livepatch to use NOTIFY_SIGNAL, > or add new users of set_notify_signal(). Yeah I know, there's a whole slew of cleanups and code removal that can happen after this series, once all archs are converted. See: https://git.kernel.dk/cgit/linux-block/log/?h=tif-task_work.arch which is all of that on top of this series. -- Jens Axboe