linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Fengguang Wu <fengguang.wu@intel.com>
To: Jan Kara <jack@suse.cz>
Cc: linux-mm@kvack.org, peterz@infradead.org
Subject: Re: [PATCH 0/2 v2] Flexible proportions for BDIs
Date: Tue, 15 May 2012 21:15:33 +0800	[thread overview]
Message-ID: <20120515131533.GA4753@localhost> (raw)
In-Reply-To: <20120514212803.GT5353@quack.suse.cz>

Hi Jan,

> > The observations for this box are
> > 
> > - the 3s and 8s periods result in roughly the same adaption speed
> > 
> > - the patch makes a really *big* difference in systems with big
> >   memory:bandwidth ratio. It's sweet! In comparison, the vanilla
> >   kernel adapts to new write bandwidth so much slower.
>   Yes, in this configuration the benefit of the new algorithm can be clearly
> seen. Together with the results of previous test I'd say 3s period is the
> best candidate.
 
Agreed. I'm fine with the fixed 3s period. 

>   Just I was thinking whether the period shouldn't be somehow set
> automatically because I'm not convinced 3s will be right for everybody...
> Maybe something based on how big fluctuations in completion rate we
> observe. But it would be tricky given the load itself changes as well. So
> for now we'll have to live with a hardwired period I guess.

Yeah, simple fixed periods should be good enough.

>   Thanks for the tests Fengguang! So is anybody against merging this?

No problem for me, when Peter's concern is addressed.

Thanks!

Fengguang

--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  parent reply	other threads:[~2012-05-15 13:16 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-03 22:39 [PATCH 0/2 v2] Flexible proportions for BDIs Jan Kara
2012-05-03 22:39 ` [PATCH 1/2] lib: Proportions with flexible period Jan Kara
2012-05-03 22:39 ` [PATCH 2/2] block: Convert BDI proportion calculations to flexible proportions Jan Kara
2012-05-07 14:47   ` Fengguang Wu
2012-05-07 15:21     ` Peter Zijlstra
2012-05-09 11:38       ` Jan Kara
2012-05-07 14:43 ` [PATCH 0/2 v2] Flexible proportions for BDIs Fengguang Wu
2012-05-09 11:37   ` Jan Kara
2012-05-10  7:31     ` Fengguang Wu
2012-05-11 14:51       ` Fengguang Wu
2012-05-13  3:29         ` Fengguang Wu
2012-05-14 21:28           ` Jan Kara
2012-05-15 11:12             ` Peter Zijlstra
2012-05-15 15:14               ` Jan Kara
2012-05-15 13:15             ` Fengguang Wu [this message]
2012-05-14 21:12         ` Jan Kara

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=20120515131533.GA4753@localhost \
    --to=fengguang.wu@intel.com \
    --cc=jack@suse.cz \
    --cc=linux-mm@kvack.org \
    --cc=peterz@infradead.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).