From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw1-f71.google.com (mail-yw1-f71.google.com [209.85.161.71]) by kanga.kvack.org (Postfix) with ESMTP id 1282A6B4884 for ; Tue, 27 Nov 2018 09:50:15 -0500 (EST) Received: by mail-yw1-f71.google.com with SMTP id 194-v6so14062885ywp.12 for ; Tue, 27 Nov 2018 06:50:15 -0800 (PST) Received: from userp2130.oracle.com (userp2130.oracle.com. [156.151.31.86]) by mx.google.com with ESMTPS id r26si2996428ywa.463.2018.11.27.06.50.13 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 27 Nov 2018 06:50:14 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 12.2 \(3445.102.3\)) Subject: Re: [RFC PATCH 3/3] mm, proc: report PR_SET_THP_DISABLE in proc From: William Kucharski In-Reply-To: <20181127131707.GW12455@dhcp22.suse.cz> Date: Tue, 27 Nov 2018 07:50:08 -0700 Content-Transfer-Encoding: 7bit Message-Id: <04647F77-FE93-4A8E-90C1-4245709B88A5@oracle.com> References: <20181120103515.25280-1-mhocko@kernel.org> <20181120103515.25280-4-mhocko@kernel.org> <0ACDD94B-75AD-4DD0-B2E3-32C0EDFBAA5E@oracle.com> <20181127131707.GW12455@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-api@vger.kernel.org, Andrew Morton , Alexey Dobriyan , linux-mm@kvack.org, LKML > On Nov 27, 2018, at 6:17 AM, Michal Hocko wrote: > > This is only about the process wide flag to disable THP. I do not see > how this can be alighnement related. I suspect you wanted to ask in the > smaps patch? No, answered below. > >> I'm having to deal with both these issues in the text page THP >> prototype I've been working on for some time now. > > Could you be more specific about the issue and how the alignment comes > into the game? The only thing I can think of is to not report VMAs > smaller than the THP as eligible. Is this what you are looking for? Basically, if the faulting VA is one that cannot be mapped with a THP due to alignment or size constraints, it may be "eligible" for THP mapping but ultimately can't be. I was just double checking that this was meant to be more of a check done before code elsewhere performs additional checks and does the actual THP mapping, not an all-encompassing go/no go check for THP mapping. Thanks, William Kucharski