Re: [PATCH] File readahead buffering

[Pavel Roskin <proski@gnu.org>]

On Tue, 2008-07-22 at 08:43 -0700, Colin D Bennett wrote:
> This patch speeds up loading a TGA image on my test system from 29
> seconds to approximately 1 second.
> 
> I noticed that on my 1 GHz test system running from an IDE CompactFlash
> drive, loading a certain TGA image in GRUB takes about 29 seconds.

I'm sorry for straying from your point, but maybe we should drop TGA
support.  It was the first image format for GRUB to support, but now PNG
is supported, and it should be better in all aspects.

> It turns out that when booting GRUB from IDE, if file buffering is
> used, GRUB hangs right after the "GRUB" message, early in the boot
> process.  So I added a flag that allows grub_main() to enable buffering
> when it is safe to do so.  It always worked file from an ISO image
> (generated with grub-mkrescue) in VMware and QEMU, but when I actually
> installed GRUB to my CompactFlash drive and booted it, it hung after
> "GRUB" if file buffering was enabled at the start.

I think we should be prefer simple and reliable code, rather than add
complexity and risks of failure to achieve higher speeds.

-- 
Regards,
Pavel Roskin