From: Matthew Wilcox <willy@infradead.org>
To: Dave Hansen <dave.hansen@intel.com>
Cc: Christopher Lameter <cl@linux.com>, Mel Gorman <mel@skynet.ie>,
linux-mm@kvack.org, linux-rdma@vger.kernel.org,
akpm@linux-foundation.org,
Thomas Schoebel-Theuer <tst@schoebel-theuer.de>,
andi@firstfloor.org, Rik van Riel <riel@redhat.com>,
Michal Hocko <mhocko@kernel.org>, Guy Shattah <sguy@mellanox.com>,
Anshuman Khandual <khandual@linux.vnet.ibm.com>,
Michal Nazarewicz <mina86@mina86.com>,
Vlastimil Babka <vbabka@suse.cz>,
David Nellans <dnellans@nvidia.com>,
Laura Abbott <labbott@redhat.com>, Pavel Machek <pavel@ucw.cz>,
Mike Kravetz <mike.kravetz@oracle.com>
Subject: Re: [RFC 1/2] Protect larger order pages from breaking up
Date: Fri, 16 Feb 2018 13:43:53 -0800 [thread overview]
Message-ID: <20180216214353.GA32655@bombadil.infradead.org> (raw)
In-Reply-To: <7fcd53ab-ba06-f80e-6cb7-73e87bcbdd20@intel.com>
On Fri, Feb 16, 2018 at 01:08:11PM -0800, Dave Hansen wrote:
> On 02/16/2018 12:15 PM, Christopher Lameter wrote:
> >> This has the potential to be really confusing to apps. If this memory
> >> is now not available to normal apps, they might plow into the invisible
> >> memory limits and get into nasty reclaim scenarios.
> >> Shouldn't this subtract the memory for MemFree and friends?
> > Ok certainly we could do that. But on the other hand the memory is
> > available if those subsystems ask for the right order. Its not clear to me
> > what the right way of handling this is. Right now it adds the reserved
> > pages to the watermarks. But then under some circumstances the memory is
> > available. What is the best solution here?
>
> There's definitely no perfect solution.
>
> But, in general, I think we should cater to the dumbest users. Folks
> doing higher-order allocations are not that. I say we make the picture
> the most clear for the traditional 4k users.
Your way might be confusing -- if there's a system which is under varying
amounts of jumboframe load and all the 16k pages get gobbled up by the
ethernet driver, MemFree won't change at all, for example.
--
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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2018-02-16 21:43 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-16 16:01 [RFC 0/2] Larger Order Protection V1 Christoph Lameter
2018-02-16 16:01 ` [RFC 1/2] Protect larger order pages from breaking up Christoph Lameter
2018-02-16 16:01 ` Christoph Lameter
[not found] ` <20180216160121.519788537-vYTEC60ixJUAvxtiuMwx3w@public.gmane.org>
2018-02-16 17:03 ` Andi Kleen
2018-02-16 17:03 ` Andi Kleen
[not found] ` <20180216170354.vpbuugzqsrrfc4js-1g7Xle2YJi4/4alezvVtWx2eb7JE58TQ@public.gmane.org>
2018-02-16 18:25 ` Christopher Lameter
2018-02-16 18:25 ` Christopher Lameter
2018-02-16 19:01 ` Dave Hansen
2018-02-16 19:01 ` Dave Hansen
2018-02-16 20:15 ` Christopher Lameter
2018-02-16 21:08 ` Dave Hansen
2018-02-16 21:08 ` Dave Hansen
2018-02-16 21:43 ` Matthew Wilcox [this message]
[not found] ` <20180216214353.GA32655-PfSpb0PWhxZc2C7mugBRk2EX/6BAtgUQ@public.gmane.org>
2018-02-16 21:47 ` Dave Hansen
2018-02-16 21:47 ` Dave Hansen
2018-02-16 18:02 ` Randy Dunlap
[not found] ` <b76028c6-c755-8178-2dfc-81c7db1f8bed-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2018-02-17 16:07 ` Mike Rapoprt
2018-02-17 16:07 ` Mike Rapoprt
2018-02-16 18:59 ` Mike Kravetz
[not found] ` <5108eb20-2b20-bd48-903e-bce312e96974-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2018-02-16 20:13 ` Christopher Lameter
2018-02-16 20:13 ` Christopher Lameter
2018-02-18 9:00 ` Guy Shattah
2018-02-18 9:00 ` Guy Shattah
2018-02-19 10:19 ` Mel Gorman
2018-02-19 14:42 ` Michal Hocko
2018-02-19 15:09 ` Christopher Lameter
2018-02-22 21:19 ` Thomas Schoebel-Theuer
2018-02-22 21:53 ` Zi Yan
2018-02-23 2:01 ` Christopher Lameter
2018-02-23 2:16 ` Zi Yan
2018-02-23 2:45 ` Christopher Lameter
2018-02-23 9:59 ` Mel Gorman
2018-02-16 16:01 ` [RFC 2/2] Page order diagnostics Christoph Lameter
2018-02-16 16:01 ` Christoph Lameter
[not found] ` <20180216160121.583566579-vYTEC60ixJUAvxtiuMwx3w@public.gmane.org>
2018-02-17 21:17 ` Pavel Machek
2018-02-17 21:17 ` Pavel Machek
2018-02-19 14:54 ` Christopher Lameter
2018-02-16 18:27 ` [RFC 0/2] Larger Order Protection V1 Christopher Lameter
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=20180216214353.GA32655@bombadil.infradead.org \
--to=willy@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=andi@firstfloor.org \
--cc=cl@linux.com \
--cc=dave.hansen@intel.com \
--cc=dnellans@nvidia.com \
--cc=khandual@linux.vnet.ibm.com \
--cc=labbott@redhat.com \
--cc=linux-mm@kvack.org \
--cc=linux-rdma@vger.kernel.org \
--cc=mel@skynet.ie \
--cc=mhocko@kernel.org \
--cc=mike.kravetz@oracle.com \
--cc=mina86@mina86.com \
--cc=pavel@ucw.cz \
--cc=riel@redhat.com \
--cc=sguy@mellanox.com \
--cc=tst@schoebel-theuer.de \
--cc=vbabka@suse.cz \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.