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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 6C19CC48BE5 for ; Wed, 16 Jun 2021 02:55:34 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BE44261246 for ; Wed, 16 Jun 2021 02:55:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BE44261246 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0D59F6B006C; Tue, 15 Jun 2021 22:55:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 086DC6B006E; Tue, 15 Jun 2021 22:55:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E43866B0070; Tue, 15 Jun 2021 22:55:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0004.hostedemail.com [216.40.44.4]) by kanga.kvack.org (Postfix) with ESMTP id B276D6B006C for ; Tue, 15 Jun 2021 22:55:32 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 52F698249980 for ; Wed, 16 Jun 2021 02:55:32 +0000 (UTC) X-FDA: 78258071304.02.7B13999 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf10.hostedemail.com (Postfix) with ESMTP id 62EB04202A0B for ; Wed, 16 Jun 2021 02:55:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=dVpMPfjIoZBEh1imMUXe8Nni76llZxak7eAb6yf1yWI=; b=IHhU53Zvfny53p+6P2ftuE0ILD M6mDhUfbn0Cxo/DrgxvhV3oLy1xMtm0Jq7C66qMJeIWwi6jnsYfgG5ayCxsZMnCLo2hKvOh8ACaMA OL1xzv8vY34BLD232vM06lqw7v/mpVGBQ3j1uMe7CPCfP/tewNFO0JGo4UkZNf5tWFme+D6djtZFQ XkIMjDPk6OtMAgoFMTzCmtfaRt0Hfrmwj0qVGHZoJWm/fqQO1THFohDRAwrvoWRLW0Lzvjbbdon/g MsgV9TqINg9SBQdV31orKG/y2fyilVsTazhz+LcsQkFVX5aj/Us8OwxnWPqSjlIZz1Wqumqos9CjT gm/PYk7Q==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1ltLhp-007WEo-0K; Wed, 16 Jun 2021 02:55:09 +0000 Date: Wed, 16 Jun 2021 03:55:04 +0100 From: Matthew Wilcox To: David Hildenbrand Cc: akpm@linuxfoundation.org, linux-mm@kvack.org, Heiko Carstens , Rafael Aquini , Vlastimil Babka , Yu Zhao , Vladimir Davydov , kirill.shutemov@linux.intel.com, Andrea Arcangeli , Donald Dutile Subject: Re: [PATCH] mm: Mark idle page tracking as BROKEN Message-ID: References: <20210612000714.775825-1-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 62EB04202A0B X-Stat-Signature: 9au8678mhft8e6nayiffo4xa3qw1eja8 Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=IHhU53Zv; dmarc=none; spf=none (imf10.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-HE-Tag: 1623812122-739458 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000736, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jun 15, 2021 at 09:41:37AM +0200, David Hildenbrand wrote: > On 12.06.21 02:07, Matthew Wilcox (Oracle) wrote: > > I might be missing something important, so some questions/comments > > > In discussion with other MM developers around how idle page tracking > > should be fixed for transparent huge pages, several expressed the opinion > > that it should be removed as it is inefficient at accomplishing the > > job that it is supposed to, and we have better mechanisms (eg uffd) for > > accomplishing the same goals these days. > > 1. A link to that discussion would be nice. I am missing some important > details in this patch description. It was on the phone in our bi-weekly THP call. As I recall, those present were Kirill, Yu Zhao, William Kucharski, Zi Yan, Vlastimil Babka. Song Liu sent apologies, and I think Mike Kravetz had a conflict. > 2. "should be fixed for transparent huge pages" -- has it always been like > this or has the behavior changed at some point? Do the semantics, and how > the feature is getting used, clearly identify this case that needs fixing as > something that really has to be fixed? Or was it always like that and > actually expected to work like that ("semtantics")? I don't know. I asked the others on the call and the answer I got was essentially "Just delete it". I'm kind of hoping the others speak up.