From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f52.google.com (mail-qg0-f52.google.com [209.85.192.52]) by kanga.kvack.org (Postfix) with ESMTP id 16C8A6B0071 for ; Mon, 22 Dec 2014 12:36:41 -0500 (EST) Received: by mail-qg0-f52.google.com with SMTP id a108so3521601qge.25 for ; Mon, 22 Dec 2014 09:36:40 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id j7si20642868qce.45.2014.12.22.09.36.38 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 22 Dec 2014 09:36:39 -0800 (PST) Date: Mon, 22 Dec 2014 12:25:00 -0500 From: Rafael Aquini Subject: Re: [PATCH] proc: task_mmu: show page size in /proc//numa_maps Message-ID: <20141222172459.GA11396@t510.redhat.com> References: <20141220183613.GA19229@phnom.home.cmpxchg.org> <20141220194457.GA3166@x61.redhat.com> <54970B49.3070104@linux.intel.com> <20141221222850.GA2038@x61.redhat.com> <5498508A.4080108@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5498508A.4080108@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: Johannes Weiner , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, oleg@redhat.com, rientjes@google.com, linux-mm@kvack.org On Mon, Dec 22, 2014 at 09:10:34AM -0800, Dave Hansen wrote: > On 12/21/2014 02:28 PM, Rafael Aquini wrote: > >>> > > I'm fine either way, it makes the change even simpler. Also, if we > >>> > > decide to get rid of page_size != PAGE_SIZE condition I believe we can > >>> > > also get rid of that "huge" hint being conditionally printed out too. > >> > > >> > That would break existing users of the "huge" flag. That makes it out > >> > of the question, right? > >> > > > Yeah, but it sort of follows the same complaint Johannes did for the > > conditional page size printouts. If we start to print out page size > > deliberately for each map regardless their backing pages being PAGE_SIZE > > long or bigger, I don't see much point on keep conditionally printing out > > the 'huge' hint out. > > Because existing userspace might be relying on it. If we take the > 'huge' hint out, userspace will break. > > > As I said before, I'm fine either way though I think > > we can keep the current behaviour, and just disambiguate page sizes != > > PAGE_SIZE as in the current proposal. > > Unless we somehow have a (really good) handle on how many apps out there > are reading and using 'huge', I think we have to keep the existing behavior. > Right. I definitely don't have anything better than what I already presented which seems beaten by your argument, already. Remaining question here is: should we print out 'pagesize' deliberately or conditionally, only to disambiguate cases where page_size != PAGE_SIZE? Have a very nice holidays folks! -- Rafael -- 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