[syslinux] Patch sensible callback framework

[H. Peter Anvin]

On 04/28/2010 02:30 AM, Steffen Winterfeldt wrote:
> On Tue, 27 Apr 2010, H. Peter Anvin wrote:
> 
>> d) I suspect we need to pass a few options to the callback.  In particular, 
>> we should have a user argument (typically a void *) which is passed in at 
>> register_callback() time, and probably information from the invocation point, 
>> e.g. the file descriptor/file pointer.
> 
> Would it be possible to make the chunk size configurable? At least the 1MB
> used in code is way too big.
> 

I'm not sure it is.  I'm moving to a 1 MB chunk size in Syslinux 4,
because with modern systems, the 64K chunk size used in Syslinux 3 is
just way too small for decent performance.

People care more about boot time than they used to (and I'm starting to
get more and more people looking at Syslinux "because it's faster than
Grub/Grub2"), and quite frankly it's a heck of a lot more important to
boot quicker than to show exactly how much time it's left to load.

The 64K number made sense for physical floppies, but that's ancient history.

The one thing one could do is to have adaptive chunk size... if the time
since the last chunk is excessive, reduce the chunk size, and vice versa.

	-hpa