Linux-mm Archive on lore.kernel.org
 help / color / Atom feed
From: Mel Gorman <mgorman@suse.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Michal Hocko <mhocko@kernel.org>,
	Vlastimil Babka <vbabka@suse.cz>,
	Andrea Argangeli <andrea@kernel.org>,
	Zi Yan <zi.yan@cs.rutgers.edu>,
	Stefan Priebe - Profihost AG <s.priebe@profihost.ag>,
	"Kirill A. Shutemov" <kirill@shutemov.name>,
	linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
	Stable tree <stable@vger.kernel.org>
Subject: Re: [PATCH 1/2] mm: thp:  relax __GFP_THISNODE for MADV_HUGEPAGE mappings
Date: Tue, 16 Oct 2018 08:46:06 +0100
Message-ID: <20181016074606.GH6931@suse.de> (raw)
In-Reply-To: <20181015154459.e870c30df5c41966ffb4aed8@linux-foundation.org>

On Mon, Oct 15, 2018 at 03:44:59PM -0700, Andrew Morton wrote:
> On Mon, 15 Oct 2018 15:30:17 -0700 (PDT) David Rientjes <rientjes@google.com> wrote:
> 
> > At the risk of beating a dead horse that has already been beaten, what are 
> > the plans for this patch when the merge window opens?
> 
> I'll hold onto it until we've settled on something.  Worst case,
> Andrea's original is easily backportable.
> 

I consider this to be an unfortunate outcome. On the one hand, we have a
problem that three people can trivially reproduce with known test cases
and a patch shown to resolve the problem. Two of those three people work
on distributions that are exposed to a large number of users. On the
other, we have a problem that requires the system to be in a specific
state and an unknown workload that suffers badly from the remote access
penalties with a patch that has review concerns and has not been proven
to resolve the trivial cases. In the case of distributions, the first
patch addresses concerns with a common workload where on the other hand
we have an internal workload of a single company that is affected --
which indirectly affects many users admittedly but only one entity directly.

At the absolute minimum, a test case for the "system fragmentation incurs
access penalties for a workload" scenario that could both replicate the
fragmentation and demonstrate the problem should have been available before
the patch was rejected.  With the test case, there would be a chance that
others could analyse the problem and prototype some fixes. The test case
was requested in the thread and never produced so even if someone were to
prototype fixes, it would be dependant on a third party to test and produce
data which is a time-consuming loop. Instead, we are more or less in limbo.

-- 
Mel Gorman
SUSE Labs

  parent reply index

Thread overview: 74+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-25 12:03 [PATCH 0/2] thp nodereclaim fixes Michal Hocko
2018-09-25 12:03 ` [PATCH 1/2] mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings Michal Hocko
2018-09-25 12:20   ` Mel Gorman
2018-09-25 12:30     ` Michal Hocko
2018-10-04 20:16   ` David Rientjes
2018-10-04 21:10     ` Andrea Arcangeli
2018-10-04 23:05       ` David Rientjes
2018-10-06  3:19         ` Andrea Arcangeli
2018-10-05  7:38     ` Mel Gorman
2018-10-05 20:35       ` David Rientjes
2018-10-05 23:21         ` Andrea Arcangeli
2018-10-08 20:41           ` David Rientjes
2018-10-09  9:48             ` Mel Gorman
2018-10-09 12:27               ` Michal Hocko
2018-10-09 13:00                 ` Mel Gorman
2018-10-09 14:25                   ` Michal Hocko
2018-10-09 15:16                     ` Mel Gorman
2018-10-09 23:03                     ` Andrea Arcangeli
2018-10-10 21:19                       ` David Rientjes
2018-10-15 22:30                         ` David Rientjes
2018-10-15 22:44                           ` Andrew Morton
2018-10-15 23:19                             ` Andrea Arcangeli
2018-10-22 20:54                               ` David Rientjes
2018-10-16  7:46                             ` Mel Gorman [this message]
2018-10-16 22:37                               ` Andrew Morton
2018-10-16 23:11                                 ` Andrea Arcangeli
2018-10-16 23:16                                   ` Andrew Morton
2018-10-17  7:08                                     ` Michal Hocko
2018-10-17  9:00                                 ` Mel Gorman
2018-10-22 21:04                               ` David Rientjes
2018-10-23  1:27                                 ` Zi Yan
2018-10-28 21:45                                   ` David Rientjes
2018-10-23  7:57                                 ` Mel Gorman
2018-10-23  8:38                                   ` Mel Gorman
2018-10-15 22:57                           ` Andrea Arcangeli
2018-10-22 20:45                             ` David Rientjes
2018-10-09 22:17               ` David Rientjes
2018-10-09 22:51                 ` Andrea Arcangeli
2018-10-10  7:54                   ` Vlastimil Babka
2018-10-10 21:00                   ` David Rientjes
2018-10-09 13:08             ` Vlastimil Babka
2018-10-09 22:21             ` Andrea Arcangeli
2018-10-29  5:17   ` Balbir Singh
2018-10-29  9:00     ` Michal Hocko
2018-10-29  9:42       ` Balbir Singh
2018-10-29 10:08         ` Michal Hocko
2018-10-29 10:56           ` Andrea Arcangeli
2018-09-25 12:03 ` [PATCH 2/2] mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask Michal Hocko
2018-09-26 13:30   ` Kirill A. Shutemov
2018-09-26 14:17     ` Michal Hocko
2018-09-26 14:22       ` Michal Hocko
2018-10-19  2:11         ` Andrew Morton
2018-10-19  8:06           ` Michal Hocko
2018-10-22 13:27             ` Vlastimil Babka
2018-10-24 23:17               ` Andrew Morton
2018-10-25  4:56                 ` Vlastimil Babka
2018-10-25 16:14                   ` Michal Hocko
2018-10-25 16:18                     ` Andrew Morton
2018-10-25 16:45                       ` Michal Hocko
2018-10-22 13:15         ` Vlastimil Babka
2018-10-22 13:30           ` Michal Hocko
2018-10-22 13:35             ` Vlastimil Babka
2018-10-22 13:46               ` Michal Hocko
2018-10-22 13:53                 ` Vlastimil Babka
2018-10-04 20:17     ` David Rientjes
2018-10-04 21:49       ` Zi Yan
2018-10-09 12:36       ` Michal Hocko
2018-09-26 13:08 ` linux-mm@ archive on lore.kernel.org (Was: [PATCH 0/2] thp nodereclaim fixes) Kirill A. Shutemov
2018-09-26 13:14   ` Michal Hocko
2018-09-26 22:22     ` Andrew Morton
2018-09-26 23:08       ` Mel Gorman
2018-09-27  0:47         ` Konstantin Ryabitsev
2018-09-26 15:25   ` Konstantin Ryabitsev
2018-09-27 11:30     ` Kirill A. Shutemov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20181016074606.GH6931@suse.de \
    --to=mgorman@suse.de \
    --cc=aarcange@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=andrea@kernel.org \
    --cc=kirill@shutemov.name \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@kernel.org \
    --cc=rientjes@google.com \
    --cc=s.priebe@profihost.ag \
    --cc=stable@vger.kernel.org \
    --cc=vbabka@suse.cz \
    --cc=zi.yan@cs.rutgers.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-mm Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mm/0 linux-mm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mm linux-mm/ https://lore.kernel.org/linux-mm \
		linux-mm@kvack.org
	public-inbox-index linux-mm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kvack.linux-mm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git