From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id BA6ED6B0038 for ; Tue, 6 Dec 2016 23:13:18 -0500 (EST) Received: by mail-pf0-f198.google.com with SMTP id j128so584264869pfg.4 for ; Tue, 06 Dec 2016 20:13:18 -0800 (PST) Received: from mail-pf0-x22a.google.com (mail-pf0-x22a.google.com. [2607:f8b0:400e:c00::22a]) by mx.google.com with ESMTPS id u71si22273623pgd.117.2016.12.06.20.13.17 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 06 Dec 2016 20:13:17 -0800 (PST) Received: by mail-pf0-x22a.google.com with SMTP id 189so74562493pfz.3 for ; Tue, 06 Dec 2016 20:13:17 -0800 (PST) Date: Tue, 6 Dec 2016 20:13:07 -0800 (PST) From: Hugh Dickins Subject: Re: [PATCH] mm: make transparent hugepage size public In-Reply-To: Message-ID: References: <877f7difx1.fsf@linux.vnet.ibm.com> <85c787f4-36ff-37fe-ff93-e42bad4b7c1e@intel.com> <20161206171905.n7qwvfb5sjxn3iif@black.fi.intel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: "Kirill A. Shutemov" , "Aneesh Kumar K.V" , Hugh Dickins , Andrew Morton , Greg Thelen , David Rientjes , Andrea Arcangeli , Dan Williams , Jan Kara , linux-mm@kvack.org On Tue, 6 Dec 2016, Dave Hansen wrote: > On 12/06/2016 09:19 AM, Kirill A. Shutemov wrote: > >>> > > We have in /proc/meminfo > >>> > > > >>> > > Hugepagesize: 2048 kB > >>> > > > >>> > > Does it makes it easy for application to find THP page size also there ? > >> > > >> > Nope. That's the default hugetlbfs page size. Even on x86, that can be > >> > changed and _could_ be 1G. If hugetlbfs is configured out, you also > >> > won't get this in meminfo. > > I think Aneesh propose to add one more line into the file. > > Ahhh, ok... > > Personally, I think Hugh did the right things. There's no reason to > waste cycles sticking a number in meminfo that never changes. Thanks, yes, that was my feeling: I prefer not to clutter /proc/meminfo with constants - especially not a unit, or granularity, as this is (too late to stop Hugepagesize of course, but I wish it weren't there, and those HugePages_ numbers in kB). On top of that, /proc/meminfo is the mm admin's "front page", whereas this is a low-level detail: it somewhat goes against our claim of "transparent" hugepages to post it up there, even though a few tests etc may find the value useful: I'd rather bury it among the tunables. (My guess is that Andrea felt rather the same, in choosing not to publish it six years ago.) But of course, that's just my/our opinion: any strong preferences? Hugh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org