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 [PATCH] bootmem speedup from the IA64 tree 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 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.