Re: upcoming kerneloops.org item: get_page_from_freelist

[Joel Becker]

On Thu, Jun 25, 2009 at 04:37:43PM -0400, Theodore Tso wrote:
> Nicely spotted.  Yeah, that's a bug; we need to do something about
> that one, too.  And what we're doing is a bit silly; it may make sense
> to use __get_free_pages if filesystem blocksize == PAGE_SIZE, but
> otherwise we should be using a sub-page allocator.  Right now, we're
> chewing up a 16k PPC page for every 4k filesystem metadata page
> allocated in journal_write_metadata_buffer(), and on x86, for the
> (admittedly uncommon) 1k block filesystem, we'd be chewing up a 4k
> page for a 1k block buffer.
> 
> 
> Both of these problems exist for both ext3 and ext4.

	And ocfs2.

Joel

-- 

Life's Little Instruction Book #337

	"Reread your favorite book."

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker@xxxxxxxxxx
Phone: (650) 506-8127
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