Re: [PATCH] Introduce jiffies_32 and related compare functions

From: David Miller
Date: Mon Dec 11 2006 - 23:28:15 EST


From: Eric Dumazet <dada1@xxxxxxxxxxxxx>
Date: Tue, 12 Dec 2006 05:09:23 +0100

> We definitly *like* being able to use bigger timeouts on 64bits platforms.
>
> Not that they are mandatory since the same application should run fine on
> 32bits kernel. But as the standard type for 'tick timestamps' is 'unsigned
> long', a change would be invasive.
>
> Maybe some applications are now relying on being able to
> sleep()/select()/poll() for periods > 30 days and only run on 64
> bits kernels.

I think one possible target would be struct timer, at least
in theory.

There is also a line of reasoning that says that on 64-bit
platforms we have some flexibility to set HZ very large, if
we wanted to at some point, and going to 32-bit jiffies
storage for some things may eliminate that kind of flexibility.

Just some food for thought...
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