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=-5.6 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 2E50EC433DF for ; Mon, 3 Aug 2020 19:17:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80BAF20A8B for ; Mon, 3 Aug 2020 19:17:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Gaa05K/B" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727885AbgHCTRh (ORCPT ); Mon, 3 Aug 2020 15:17:37 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:28540 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726007AbgHCTRg (ORCPT ); Mon, 3 Aug 2020 15:17:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1596482255; 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=JlRPcUiCaDRmWVJAxXsR/XyWp+YNVRWRo58Ec1/lUXg=; b=Gaa05K/BUJhcmroMdsPLWDt5P91PpAI/1beHl7cit0vBGMVoX9sRwET8LLWCXdHXt66HXD zgPZrgEB2QE5tJpUxrG1rbxnr+6L4zRFgdy/+bWh38alrAZ+2PW9bkfI+y3oDaxZaC6t1L vwSYZUz/u1a+juh9SDVlEJ/rY9v1NRY= 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-495-l43cMm2WM0i38uQMayFyhA-1; Mon, 03 Aug 2020 15:17:31 -0400 X-MC-Unique: l43cMm2WM0i38uQMayFyhA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9B982100AA27; Mon, 3 Aug 2020 19:17:29 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.40.192.110]) by smtp.corp.redhat.com (Postfix) with SMTP id 0C46E19C66; Mon, 3 Aug 2020 19:17:26 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Mon, 3 Aug 2020 21:17:29 +0200 (CEST) Date: Mon, 3 Aug 2020 21:17:25 +0200 From: Oleg Nesterov To: "chunlei.wang" Cc: Andrew Morton , Matthias Brugger , Peter Zijlstra , "Aneesh Kumar K.V" , Will Deacon , linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com, weiwei.zhang@mediatek.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] siganl: ignore other signals when doing coredump Message-ID: <20200803191725.GA2078@redhat.com> References: <1595487143.29785.9.camel@mbjsdccf07> <20200723175126.cf6a660e46c8da26b1293eb4@linux-foundation.org> <1596185654.11648.1.camel@mbjsdccf07> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1596185654.11648.1.camel@mbjsdccf07> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/31, chunlei.wang wrote: > > Please tell us much more about why you think Linux would benefit from > this change. Precisely what operational problems are you seeing with > the current code? > => > Sorry for the late reply. > > If coredump is incomplete, R&D can not find root cause through > coredump. > If the issue is seldom, this modification will speed up the process of > solving the problem. To be honest, I do not even know what can I say, except that I disagree with this change. The very idea looks wrong to me. Granted, SIGKILL can kill the process which does something useful. Say, dumps a core. So what? Where does this SIGKILL come from? How often does this happen? And why do you think the core dumping is special? Say, you try to debug the buggy application, but a sudden SIGKILL kills the debuggee and you lose the debugging session. Does this mean that the kernel needs another patch to protect the process running under gdb from SIGKILL? I don't think so. Please feel free to resend this patch, but it needs a very convincing changelog. And please send it to lkml. Oleg.