linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Wei Yang <richard.weiyang@gmail.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>,
	mgorman@techsingularity.net, jiang.liu@linux.intel.com,
	akpm@linux-foundation.org, tj@kernel.org, mingo@kernel.org,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC] calc_memmap_size() isn't accurate and one suggestion to improve
Date: Sun, 9 Apr 2017 09:44:57 +0800	[thread overview]
Message-ID: <20170409014457.GA24681@WeideMBP.lan> (raw)
In-Reply-To: <20170403091818.GI24661@dhcp22.suse.cz>

[-- Attachment #1: Type: text/plain, Size: 1158 bytes --]

On Mon, Apr 03, 2017 at 11:18:19AM +0200, Michal Hocko wrote:
>On Tue 28-03-17 09:11:37, Wei Yang wrote:
>> Hi, masters,
>> 
>> # What I found
>> 
>> I found the function calc_memmap_size() may not be that accurate to get the
>> pages for memmap.
>> 
>> The reason is:
>> 
>> > memmap is allocated on a node base,
>> > while the calculation is on a zone base
>> 
>> This applies both to SPARSEMEM and FLATMEM.
>> 
>> For example, on my laptop with 6G memory, all the memmap space is allocated
>> from ZONE_NORMAL.
>
>Please try to be more specific. Why is this a problem? Are you trying to
>fix some bad behavior or you want to make it more optimal?
>
>I am sorry I didn't look closer into your proposal but I am quite busy
>and other people are probably in a similar situation. If you want to get
>a proper feedback please try to state the problem and be explicit if it
>is user observable.

Michal

Glad to hear from you.

Sure, let me do more investigation on this and try some experiment to see
whether this change is observable.

Have a nice day~

>-- 
>Michal Hocko
>SUSE Labs

-- 
Wei Yang
Help you, Help me

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]

      reply	other threads:[~2017-04-09  1:45 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-28  1:11 [RFC] calc_memmap_size() isn't accurate and one suggestion to improve Wei Yang
2017-04-03  9:18 ` Michal Hocko
2017-04-09  1:44   ` Wei Yang [this message]

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=20170409014457.GA24681@WeideMBP.lan \
    --to=richard.weiyang@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=jiang.liu@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mgorman@techsingularity.net \
    --cc=mhocko@kernel.org \
    --cc=mingo@kernel.org \
    --cc=tj@kernel.org \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).