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 C98CEC4320A for ; Mon, 26 Jul 2021 08:20:40 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4E8A460BBB for ; Mon, 26 Jul 2021 08:20:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4E8A460BBB Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 535676B0033; Mon, 26 Jul 2021 04:20:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4E44A8D0002; Mon, 26 Jul 2021 04:20:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3D30E8D0001; Mon, 26 Jul 2021 04:20:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0192.hostedemail.com [216.40.44.192]) by kanga.kvack.org (Postfix) with ESMTP id 2133A6B0033 for ; Mon, 26 Jul 2021 04:20:39 -0400 (EDT) Received: from smtpin35.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id C7BE38249980 for ; Mon, 26 Jul 2021 08:20:38 +0000 (UTC) X-FDA: 78404042556.35.1D75647 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf03.hostedemail.com (Postfix) with ESMTP id 51CCD3004459 for ; Mon, 26 Jul 2021 08:20:37 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id CC70A21ED4; Mon, 26 Jul 2021 08:20:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1627287635; 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=dqI+Ee5Giqt9QLyCDiFV9fDN7znSnNwARp3fuiYiLdc=; b=upGNLqFkSmmkH98NSEEE4bVXU8s7YEF69vWIoYCbwsCfkOJeThVu1P9KvzjIszLt4yOM67 9gQr91/PzjGv/pKyAhnFGNknnsIYgyUNREsNn2fE2eRjknWQhYziaJMBBVchNQrYogaE0n IoVOunQuBNWXWdYqbNXTs2AzKVlwXKk= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 7577DA3B8B; Mon, 26 Jul 2021 08:20:35 +0000 (UTC) Date: Mon, 26 Jul 2021 10:20:35 +0200 From: Michal Hocko To: Shakeel Butt Cc: Suren Baghdasaryan , Andrew Morton , David Rientjes , Matthew Wilcox , Johannes Weiner , Roman Gushchin , Rik van Riel , Minchan Kim , Christian Brauner , Christoph Hellwig , Oleg Nesterov , David Hildenbrand , Jann Horn , Andy Lutomirski , Christian Brauner , Florian Weimer , jengelh@inai.de, Tim Murray , Linux API , Linux MM , LKML , kernel-team Subject: Re: [PATCH v3 1/2] mm: introduce process_mrelease system call Message-ID: References: <20210723011436.60960-1-surenb@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 51CCD3004459 Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=upGNLqFk; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf03.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com X-Stat-Signature: gpss36ort3g5rzsioaqnngyc3amfcfof X-HE-Tag: 1627287637-417006 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu 22-07-21 19:03:56, Shakeel Butt wrote: > On Thu, Jul 22, 2021 at 6:14 PM Suren Baghdasaryan wrote: > > > [...] > > + > > + mmap_read_lock(mm); > > How about mmap_read_trylock(mm) and return -EAGAIN on failure? Btw. wether there is a non-blocking variant or not we should use killable waiting to make sure the task calling into this is killable by userspace (e.g. to implement a timeout based approach). -- Michal Hocko SUSE Labs