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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 62E1AC64E75 for ; Wed, 18 Nov 2020 19:10:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3D102222C for ; Wed, 18 Nov 2020 19:10:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="Ns+TtYTH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727235AbgKRTKZ (ORCPT ); Wed, 18 Nov 2020 14:10:25 -0500 Received: from mx2.suse.de ([195.135.220.15]:56318 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726891AbgKRTKY (ORCPT ); Wed, 18 Nov 2020 14:10:24 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1605726622; h=from:from:reply-to: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=PHqRgFGLF7++rqv3Lsk3obYtItSqoxTqnImH6UJRi/k=; b=Ns+TtYTHur4leXJTxMzoo9DXqqyYd+4vWOKF4laQo54XNVwJNpx5I4XcyD1N0KtmfExnzn ujqDIYvw9vlQF7h5AaepV8GurtLZI/6QOJ1nIjFcygxUf0f4TMMrewls6JVsJ4AIxWRQRZ P4IBCP/Ra5X2Ot4N5jkXSxvPfch+QQM= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id B3577BC5A; Wed, 18 Nov 2020 19:10:22 +0000 (UTC) Date: Wed, 18 Nov 2020 20:10:21 +0100 From: Michal Hocko To: Andrew Morton Cc: Suren Baghdasaryan , David Rientjes , Matthew Wilcox , Johannes Weiner , Roman Gushchin , Rik van Riel , Christian Brauner , Oleg Nesterov , Tim Murray , linux-api@vger.kernel.org, linux-mm , LKML , kernel-team , Minchan Kim Subject: Re: [PATCH 1/1] RFC: add pidfd_send_signal flag to reclaim mm while killing a process Message-ID: <20201118154334.GT12284@dhcp22.suse.cz> References: <20201113173448.1863419-1-surenb@google.com> <20201113155539.64e0af5b60ad3145b018ab0d@linux-foundation.org> <20201113170032.7aa56ea273c900f97e6ccbdc@linux-foundation.org> <20201113171810.bebf66608b145cced85bf54c@linux-foundation.org> <20201113181632.6d98489465430a987c96568d@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201113181632.6d98489465430a987c96568d@linux-foundation.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 13-11-20 18:16:32, Andrew Morton wrote: [...] > It's all sounding a bit painful (but not *too* painful). But to > reiterate, I do think that adding the ability for a process to shoot > down a large amount of another process's memory is a lot more generally > useful than tying it to SIGKILL, agree? I am not sure TBH. Is there any reasonable usecase where uncoordinated memory tear down is OK and a target process which is able to see the unmapped memory? -- Michal Hocko SUSE Labs