Hi,
On Wed, Oct 25, 2023 at 02:09:37PM +0000, Jeshua Smith wrote:
<... snip a very detailed and good explanation... >
> Writing 128 nor-flash pages would then take 120us * 128 = 15ms
> typical, or 1800us * 128 = 230.4ms max.
This is perfectly suitable to be in the commit message - it explains in
exact detail why the change is needed.
> Actual use case:
>
> Kernel panic -> Pstore calls APEI's ERST code to write the ~32KB error
> log to persistent store -> ERST code writes the error log to
> nor-flash, which takes more than 1ms to complete. This is expected, as
> communicated by the platform to the OS via the maximum time field in
> the ERST table.
This is actually very important and it justifies the need for that
change even more - you want to flush out the complete panic message to
pstore and not only the first couple of lines.
> ... and therefore the extended (ERST-defined) timeout is only applied
> for implementations that indicate that they are "slow". I assume that
> platforms which bother to set the "slow" bit will also specify actual
> timings, and platforms which don't are OK with the current 1ms
> timeout.
Yap, makes perfect sense to me.
> Does that answer your questions?
Yes, thanks for taking the time to explain this in such a detail and
precisely. I think you should use the main bits of what you wrote here
and add them to the commit message - after this there are no more
questions why this patch is needed, IMO.
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
