Re: Incorrect comment in disk.h (and bigger cache) ?

[Benjamin Herrenschmidt]

On Thu, 2023-02-09 at 01:24 +0100, Mihai Moldovan wrote:
> > I'm tempted to increase this to speed things up on UEFI especially,
> > either
> > that or maybe changing grub_fshelp_read_file() so that get_block
> > can
> > optionally return a count of contiguous blocks so we can issue
> > larger
> > requests ?
> 
> Is that really necessary? Note that this is also used for legacy
> MBR/BIOS
> systems and I faintly remember places using that, which may do so in
> a fixed
> way, so I advise to check it well if you really intend to change it.
> 
That's ok as the MBS/BIOS bits will impose limits at other levels.

The reason I want larger IOs is that it will help with cloud setups
where the EFI "disk" is actually  some kind of networked storage. We
are chasing milliseconds in instance launch times :-)

Anyways, I think the "right" approach is to make get_blocks() called
by grub_fshelp_read_file() optionally return the number of contiguous
blocks, so we can chose to do larger chunks.

I'll look into it if/when I have time.

Cheers,
Ben.