Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751820AbbG1W1B (ORCPT ); Tue, 28 Jul 2015 18:27:01 -0400 Received: from mail-pa0-f50.google.com ([209.85.220.50]:32808 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750891AbbG1W1A (ORCPT ); Tue, 28 Jul 2015 18:27:00 -0400 Date: Tue, 28 Jul 2015 15:26:54 -0700 From: =?iso-8859-1?Q?J=F6rn?= Engel To: David Rientjes Cc: Mike Kravetz , "linux-mm@kvack.org" , linux-kernel Subject: Re: hugetlb pages not accounted for in rss Message-ID: <20150728222654.GA28456@Sligo.logfs.org> References: <55B6BE37.3010804@oracle.com> <20150728183248.GB1406@Sligo.logfs.org> <55B7F0F8.8080909@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1527 Lines: 34 On Tue, Jul 28, 2015 at 03:15:17PM -0700, David Rientjes wrote: > > Starting to account hugetlb pages in rss may lead to breakage in userspace > and I would agree with your earlier suggestion that just removing any test > for rss would be appropriate. What would you propose for me then? I have 80% RAM or more in reserved hugepages. OOM-killer is not a concern, as it panics the system - the alternatives were almost universally silly and we didn't want to deal with system in unpredictable states. But knowing how much memory is used by which process is a concern. And if you only tell me about the small (and continuously shrinking) portion, I essentially fly blind. That is not a case of "may lead to breakage", it _is_ broken. Ideally we would have fixed this in 2002 when hugetlbfs was introduced. By now we might have to introduce a new field, rss_including_hugepages or whatever. Then we have to update tools like top etc. to use the new field when appropriate. No fun, but might be necessary. If we can get away with including hugepages in rss and fixing the OOM killer to be less silly, I would strongly prefer that. But I don't know how much of a mess we are already in. J?rn -- Time? What's that? Time is only worth what you do with it. -- Theo de Raadt -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/