2006-01-25 16:56:18

by Shaun Jackman

[permalink] [raw]
Subject: Replaying a list of blocks into the cache (BootCache)

I'm attempting to speed up the boot of an embedded system. I've found
that forcing certain key shared libraries to cache early by copying
them from the file system to a tmpfs early in the boot made a big
difference -- on the order of twenty seconds. I'm not even accessing
these shared libraries from the tmpfs; I'm just using this trick to
make sure the libraries stay in memory. Seeing what a big difference
this simple trick made, I wanted to see what else I could accomplish
by making use of the file system cache.

This made me think of the OS X BootCache feature, which saves the list
of disk blocks accessed during the boot sequence and replays that
list on the next boot. Is there anything like this in Linux?

Please cc me in your reply. Thanks!
Shaun


2006-01-25 17:58:28

by Thomas Petazzoni

[permalink] [raw]
Subject: Re: Replaying a list of blocks into the cache (BootCache)

Hi,

[ Sorry, I'm reading linux-kernel through the newsgroup, so my reply may
not contain the correct references, and may break the threading. ]

Shaun Jackman a ?crit :

> This made me think of the OS X BootCache feature, which saves the list
> of disk blocks accessed during the boot sequence and replays that
> list on the next boot. Is there anything like this in Linux?

This has been discussed 2 years ago on KernelTrap:
http://kerneltrap.org/node/2157

I don't know if there have been further developments in this area.

Sincerly,

Thomas
--
Thomas Petazzoni, [email protected]