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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 39A2EC2D0E1 for ; Wed, 9 Sep 2020 21:52:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ED89020C09 for ; Wed, 9 Sep 2020 21:52:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="uhJlBGKa" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728442AbgIIVwR (ORCPT ); Wed, 9 Sep 2020 17:52:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726226AbgIIVwM (ORCPT ); Wed, 9 Sep 2020 17:52:12 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E40DBC061573 for ; Wed, 9 Sep 2020 14:52:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=9AelBTRGGkaycQWCIOP8/Ny69L3JnwJ2r2LMDHo8IXc=; b=uhJlBGKaw4qHaktb6IwOYqmKKP fjkviTcwwyFqfqZ3qvJZ88vgCUgR5rDFTt6bStcnT1bXx3rH9LlCWapM1lQ3hdU+/cNPY2Qo2jFaX LWCLK6t49O/+R09xAutwb83n97LxQmkPai5qBqGobBdwOxN1g/gDe/diTqFrGjw5vK2kQEeYvRVpg qJ4EMLxgqEQCIpHJJ+pdvAO1K3RJxBRvuQDqkXOrbbm4KhMpyJ4+bZD6PR4dxTA4DED/srM96Q7MI f7OUL8bQR2yJPtremyonRj/QIN0GHlKD3x2X71y5Samsejj6VTX08qM2JskDow2G9rVdd81fIp96e 1ZW5+piw==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kG80f-0000Zc-4A; Wed, 09 Sep 2020 21:52:09 +0000 Date: Wed, 9 Sep 2020 22:52:09 +0100 From: Matthew Wilcox To: Chris Down Cc: Vlastimil Babka , zangchunxin@bytedance.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Muchun Song Subject: Re: [PATCH v2] mm/vmscan: fix infinite loop in drop_slab_node Message-ID: <20200909215209.GP6583@casper.infradead.org> References: <20200909152047.27905-1-zangchunxin@bytedance.com> <16906d44-9e3c-76a1-f1a9-ced61e865467@suse.cz> <20200909214724.GA1577471@chrisdown.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200909214724.GA1577471@chrisdown.name> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 09, 2020 at 10:47:24PM +0100, Chris Down wrote: > Vlastimil Babka writes: > > - Exit also on other signals such as SIGABRT, SIGTERM? If I write to drop_caches > > and think it's too long, I would prefer to kill it by ctrl-c and not just kill > > Oh dear, fatal_signal_pending() doesn't consider cases with no more > userspace instructions due to SIG_DFL on TERM/INT etc, that seems misleading > :-( I had (naively) believed it internally checks the same set as > TASK_KILLABLE. > > Chuxin, Muchun, can you please make it work using TASK_KILLABLE in a similar > way to how schedule_timeout_killable and friends do it instead, so that > other signals will be caught? You're mistaken. if (sig_fatal(p, sig) && !(signal->flags & SIGNAL_GROUP_EXIT) && !sigismember(&t->real_blocked, sig) && (sig == SIGKILL || !p->ptrace)) { ... sigaddset(&t->pending.signal, SIGKILL); static inline int __fatal_signal_pending(struct task_struct *p) { return unlikely(sigismember(&p->pending.signal, SIGKILL)); }