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=-5.5 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,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 F369FC43467 for ; Fri, 9 Oct 2020 15:21:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D49E22284 for ; Fri, 9 Oct 2020 15:21:30 +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="brT8d82R" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389236AbgJIPVa (ORCPT ); Fri, 9 Oct 2020 11:21:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387664AbgJIPVa (ORCPT ); Fri, 9 Oct 2020 11:21:30 -0400 Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3645CC0613D2 for ; Fri, 9 Oct 2020 08:21:28 -0700 (PDT) Received: by mail-pg1-x544.google.com with SMTP id g9so7424163pgh.8 for ; Fri, 09 Oct 2020 08:21:28 -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=1l5bQ+lqgCSA/OaJHeyIm/1E5UGT669jRSDiiWTQv9I=; b=brT8d82RuNrUqMXWLQfdFIuobfKiEJIqSIwJD8P+BnfqDb3rb8iuhuCoXdtHdH9tFh Pva7sJfJoXRCNIb6ZKbIQ2OM+6GTuJbzIijQBwTzaNCUhnq7ovAK6X5WYkV6iVdHb8O7 biCufPq1qQLyo/3OgQ3z1QqGonl2Ts0G8YtrPjbKVwk7Lq7YydxQ5qDX6mmRGzTlssQU EX863ruA2BMcXl2pCSqsVtkJXLQGqw7/L+YGwgg6bdIu3TJLnDn7X39xJ+kvRZjIXYu7 40ScFjJhy8xgya7iFVHluj7DYlCrkxomHZheUpmww4EnWGLjTc0vSmtz3vMu+CO/AVaQ wJMg== 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=1l5bQ+lqgCSA/OaJHeyIm/1E5UGT669jRSDiiWTQv9I=; b=HA1zCrLzT5WBa2CYjHSOeTa8ErWb2YlB052sUoJ8jEd0cSaQaXqtj9ijtH0qEne8mt ac8YU2e0V251ohd7I3NkoqShXa3RhoLGU7ji3kSLv9r6gYDKbZk7T70V/WEMKiTIrwHR rK/dMs6YhQ1ypkJfbnIwCQN3moGAWE45vvA+2VUGAeL9e1I0VB3UeGfret5HvBFF0Cbc 6vWO0hlJwONcbQSe0Zz9qfOaYO5Cf6cdntgoVEFzbiPFQrSuzzMiZsc07bOQcAx1bhRs Vv1bwYFgK+63z7ciJQIIj41UsAWVHGy5b7OW+pd99Gwel+/98MCa69x70LjUuy7G2Zjb ProA== X-Gm-Message-State: AOAM531SA4W+xCOpZUf3qENM1eq5VotikyN83B4v7ie7ievMs1NZ1F7G vA6/IS/SDwGB4WnLHSQdSUccEw== X-Google-Smtp-Source: ABdhPJwUMZx9n5iEt9MhvI4G8mWEw6oBLxru3MuJM1VuUFIOvRfTfC6Jet8YwH35gE0WPxK1J+y/Cw== X-Received: by 2002:a17:90b:4189:: with SMTP id hh9mr5249219pjb.199.1602256887739; Fri, 09 Oct 2020 08:21:27 -0700 (PDT) Received: from [192.168.1.134] ([66.219.217.173]) by smtp.gmail.com with ESMTPSA id t13sm11594162pjo.15.2020.10.09.08.21.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 09 Oct 2020 08:21:27 -0700 (PDT) Subject: Re: [PATCHSET RFC v3 0/6] Add support for TIF_NOTIFY_SIGNAL To: Miroslav Benes , Oleg Nesterov Cc: linux-kernel@vger.kernel.org, io-uring@vger.kernel.org, peterz@infradead.org, tglx@linutronix.de, live-patching@vger.kernel.org References: <20201005150438.6628-1-axboe@kernel.dk> <20201008145610.GK9995@redhat.com> From: Jens Axboe Message-ID: Date: Fri, 9 Oct 2020 09:21:25 -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: 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 10/9/20 2:01 AM, Miroslav Benes wrote: > On Thu, 8 Oct 2020, Oleg Nesterov wrote: > >> On 10/05, Jens Axboe wrote: >>> >>> Hi, >>> >>> The goal is this patch series is to decouple TWA_SIGNAL based task_work >>> from real signals and signal delivery. >> >> I think TIF_NOTIFY_SIGNAL can have more users. Say, we can move >> try_to_freeze() from get_signal() to tracehook_notify_signal(), kill >> fake_signal_wake_up(), and remove freezing() from recalc_sigpending(). >> >> Probably the same for TIF_PATCH_PENDING, klp_send_signals() can use >> set_notify_signal() rather than signal_wake_up(). > > Yes, that was my impression from the patch set too, when I accidentally > noticed it. > > Jens, could you CC our live patching ML when you submit v4, please? It > would be a nice cleanup. Definitely, though it'd be v5 at this point. But we really need to get all archs supporting TIF_NOTIFY_SIGNAL first. Once we have that, there's a whole slew of cleanups that'll fall out naturally: - Removal of JOBCTL_TASK_WORK - Removal of special path for TWA_SIGNAL in task_work - TIF_PATCH_PENDING can be converted and then removed - try_to_freeze() cleanup that Oleg mentioned And probably more I'm not thinking of right now :-) -- Jens Axboe