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=-5.2 required=3.0 tests=BAYES_00, 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 20409C4338F for ; Tue, 27 Jul 2021 12:01:43 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 81BE961A3D for ; Tue, 27 Jul 2021 12:01:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 81BE961A3D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ucw.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id DEE696B0036; Tue, 27 Jul 2021 08:01:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D9E756B005D; Tue, 27 Jul 2021 08:01:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CB2AF6B006C; Tue, 27 Jul 2021 08:01:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0246.hostedemail.com [216.40.44.246]) by kanga.kvack.org (Postfix) with ESMTP id AEF836B0036 for ; Tue, 27 Jul 2021 08:01:41 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 6024C824999B for ; Tue, 27 Jul 2021 12:01:41 +0000 (UTC) X-FDA: 78408228402.23.9BB7BD2 Received: from jabberwock.ucw.cz (jabberwock.ucw.cz [46.255.230.98]) by imf25.hostedemail.com (Postfix) with ESMTP id 6D3EEB000E36 for ; Tue, 27 Jul 2021 12:01:38 +0000 (UTC) Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 6BBB41C0B76; Tue, 27 Jul 2021 14:01:35 +0200 (CEST) Date: Tue, 27 Jul 2021 14:01:35 +0200 From: Pavel Machek To: David Hildenbrand Cc: Michal Hocko , Evan Green , Andrew Morton , Alex Shi , Alistair Popple , Jens Axboe , Johannes Weiner , Joonsoo Kim , "Matthew Wilcox (Oracle)" , Miaohe Lin , Minchan Kim , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org Subject: Re: [PATCH v2] mm: Enable suspend-only swap spaces Message-ID: <20210727120135.GA32265@duo.ucw.cz> References: <20210709105012.v2.1.I09866d90c6de14f21223a03e9e6a31f8a02ecbaf@changeid> <30dddfb1-388c-a593-0987-73e821216da9@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="7JfCtLOvnd9MIVvH" Content-Disposition: inline In-Reply-To: <30dddfb1-388c-a593-0987-73e821216da9@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 6D3EEB000E36 Authentication-Results: imf25.hostedemail.com; dkim=none; dmarc=none; spf=none (imf25.hostedemail.com: domain of pavel@ucw.cz has no SPF policy when checking 46.255.230.98) smtp.mailfrom=pavel@ucw.cz X-Stat-Signature: o9yzsdyecr373br4ayer7s1bk4umcaep X-HE-Tag: 1627387298-796862 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: --7JfCtLOvnd9MIVvH Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > > Could you expand some more on why a strict exclusion is really > > necessary? I do understand that one might not want to have swap storage > > available all the time but considering that swapon is really a light > > operation so something like the following should be a reasonable > > workaround, no? > > swapon storage/file > > s2disk > > swapoff storage >=20 > I'm certainly not a hibernation expert, but I'd guess this can also be > triggered by HW events, so from the kernel and not only from user space > where your workaround would apply. I should know about hibernation, and I'm not aware of any case where we do hibernation from kernel. Userspace should be always involved. Best regards, Pavel --=20 http://www.livejournal.com/~pavelmachek --7JfCtLOvnd9MIVvH Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRPfPO7r0eAhk010v0w5/Bqldv68gUCYP/1nwAKCRAw5/Bqldv6 8pHjAJ44gAydZJxSbawcNsnD0Vx7XPnYNQCeOFPhMYsWI6XozIkeaEayJDVpRxc= =XzQI -----END PGP SIGNATURE----- --7JfCtLOvnd9MIVvH--