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=-2.5 required=3.0 tests=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 36366C3A59E for ; Fri, 16 Aug 2019 08:27:43 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F0BDB2077C for ; Fri, 16 Aug 2019 08:27:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F0BDB2077C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9C0516B0007; Fri, 16 Aug 2019 04:27:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9705F6B0008; Fri, 16 Aug 2019 04:27:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 886846B000A; Fri, 16 Aug 2019 04:27:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0221.hostedemail.com [216.40.44.221]) by kanga.kvack.org (Postfix) with ESMTP id 676266B0007 for ; Fri, 16 Aug 2019 04:27:42 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 15339181AC9AE for ; Fri, 16 Aug 2019 08:27:42 +0000 (UTC) X-FDA: 75827612364.30.jail62_8fbf45631f1d X-HE-Tag: jail62_8fbf45631f1d X-Filterd-Recvd-Size: 3214 Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by imf34.hostedemail.com (Postfix) with ESMTP for ; Fri, 16 Aug 2019 08:27:41 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E376FAFC3; Fri, 16 Aug 2019 08:27:39 +0000 (UTC) Date: Fri, 16 Aug 2019 10:27:38 +0200 From: Michal Hocko To: Daniel Vetter Cc: Jason Gunthorpe , Feng Tang , Randy Dunlap , Kees Cook , Masahiro Yamada , Peter Zijlstra , Intel Graphics Development , Jann Horn , LKML , DRI Development , Linux MM , =?iso-8859-1?B?Suly9G1l?= Glisse , Ingo Molnar , Thomas Gleixner , David Rientjes , Wei Wang , Daniel Vetter , Andrew Morton , Andy Shevchenko , Christian =?iso-8859-1?Q?K=F6nig?= Subject: Re: [Intel-gfx] [PATCH 2/5] kernel.h: Add non_block_start/end() Message-ID: <20190816082738.GC27790@dhcp22.suse.cz> References: <20190815132127.GI9477@dhcp22.suse.cz> <20190815141219.GF21596@ziepe.ca> <20190815155950.GN9477@dhcp22.suse.cz> <20190815165631.GK21596@ziepe.ca> <20190815174207.GR9477@dhcp22.suse.cz> <20190815182448.GP21596@ziepe.ca> <20190815190525.GS9477@dhcp22.suse.cz> <20190815191810.GR21596@ziepe.ca> <20190815193526.GT9477@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) 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 15-08-19 22:16:43, Daniel Vetter wrote: > On Thu, Aug 15, 2019 at 9:35 PM Michal Hocko wrote: [...] > > > The last detail is I'm still unclear what a GFP flags a blockable > > > invalidate_range_start() should use. Is GFP_KERNEL OK? > > > > I hope I will not make this muddy again ;) > > invalidate_range_start in the blockable mode can use/depend on any sleepable > > allocation allowed in the context it is called from. So in other words > > it is no different from any other function in the kernel that calls into > > allocator. As the API is missing gfp context then I hope it is not > > called from any restricted contexts (except from the oom which we have > > !blockable for). > > Hm, that's new to me. I thought mmu notifiers very much can be called > from direct reclaim paths, so you have to be extremely careful with > getting back into that one. Correct, I should have added that notifier callbacks ideally do not allocate any memory. They can block and even that is quite a pain to be honest. -- Michal Hocko SUSE Labs