lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Sat, 19 Jan 2008 20:10:20 -0800
From:	Daniel Phillips <>
To:	"Abhishek Rai" <>
Cc:	"Theodore Tso" <>,
	"Christoph Hellwig" <>,
	"Andrew Morton" <>,,,
Subject: Re: [CALL FOR TESTING] Make Ext3 fsck way faster [2.6.24-rc6 -mm patch]

On Thursday 17 January 2008 04:47, Abhishek Rai wrote:
> > if Abhishek wants to pursue it, would be to pull in all of the
> > indirect blocks when the file is opened, and create an in-memory
> > extent tree that would speed up access to the file.  It's rarely
> > worth doing this without metaclustering, since it doesn't help for
> > sequential I/O, only random I/O, but with metaclustering it would
> > also be a win for sequential I/O.  (This would also remove the
> > minor performance degradation for sequential I/O imposed by
> > metaclustering, and in fact improve it slightly for really big
> > files.)
> Also, since the in memory extent tree will now occupy much less
> space, we can keep them cached for a much longer time which will
> improve performance of random reads. The new metaclustering patch is
> more amenable to this trick since it reduces fragmentation thereby
> reducing the number of extents.

I can see value in preemptively loading indirect blocks into the buffer 
cache, but is building a second-order extent tree really worth the 
effort?  Probing the buffer cache is very fast.


To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists