From: Anton Blanchard <anton@samba.org>
To: Christoph Hellwig <hch@lst.de>
Cc: akpm@zip.com.au, davidm@napali.hpl.hp.com, linux-mm@kvack.org
Subject: Re: [PATCH] bootmem speedup from the IA64 tree
Date: Fri, 11 Apr 2003 01:25:04 +1000 [thread overview]
Message-ID: <20030410152504.GA18082@krispykreme> (raw)
In-Reply-To: <20030410122421.A17889@lst.de>
> This is a performance speed up and some minor indendation fixups.
>
> The problem is that the bootmem code is (a) hugely slow and (b) has
> execution that grow quadratically with the size of the bootmap bitmap.
> This causes noticable slowdowns, especially on machines with (relatively)
> large holes in the physical memory map. Issue (b) is addressed by
> maintaining the "last_success" cache, so that we start the next search
> from the place where we last found some memory (this part of the patch
> could stand additional reviewing/testing). Issue (a) is addressed by
> using find_next_zero_bit() instead of the slow bit-by-bit testing.
FYI I have some ppc64 machines with a memory layout of
1GB MEM
3GB IO
63GB MEM
And see the same problem.
Anton
--
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:"aart@kvack.org">aart@kvack.org</a>
prev parent reply other threads:[~2003-04-10 15:25 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-04-10 10:24 Christoph Hellwig
2003-04-10 10:35 ` Andrew Morton
2003-04-10 14:18 ` Martin J. Bligh
2003-04-10 16:46 ` Martin J. Bligh
2003-04-10 13:59 ` Benjamin LaHaise
2003-04-10 20:43 ` Andrew Morton
2003-04-10 20:34 ` Martin J. Bligh
2003-04-10 21:07 ` Andrew Morton
2003-04-10 21:02 ` William Lee Irwin III
2003-04-11 20:32 ` Rik van Riel
2003-04-11 20:57 ` Andrew Morton
2003-04-11 21:27 ` David Mosberger
2003-04-11 20:58 ` David Mosberger
2003-04-10 15:25 ` Anton Blanchard [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=20030410152504.GA18082@krispykreme \
--to=anton@samba.org \
--cc=akpm@zip.com.au \
--cc=davidm@napali.hpl.hp.com \
--cc=hch@lst.de \
--cc=linux-mm@kvack.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