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

[Daniel Kiper]

On Tue, Feb 14, 2023 at 11:09:48AM +1100, Benjamin Herrenschmidt wrote:
> 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.

It seems to me that this approach or something similar will be better
than just increasing disk cache size.

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

Cool! Thanks!

Daniel