Re: [Xen-devel] [timer/ticks related] dom0 hang during boot on large 1TB system

[Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>]

On Mon, 21 Dec 2009 20:00:25 -0800
Mukesh Rathor <mukesh.rathor@xxxxxxxxxx> wrote:

> On Mon, 21 Dec 2009 14:17:57 -0500
> Steve Ofsthun <steve.ofsthun@xxxxxxxxxx> wrote:
> 
> > As Keir suggests, the correct solution is probably to use the
> > time_before/after macros appropriately.
> > 
> > The proposed code avoids the problem by accessing jiffies_64
> > instead.
> 
> can't use time_after/before as they do signed comparisions. 
>   time_after(a,b): ((long)(b) - (long)(a) < 0))
> 
> thus, time_after(0xFFFEDB09, 0xFFFEDB08) will return true as will
> time_after(0x1020, 0xFFFEDB08) as they are both after 0xFFFEDB08.
> 
> For wrapping, unsigned comparision must be done, which is also the
> jiffies data type. 
> 

actually my bad. it can't be used in if statement to check for
wrapping, but i can use it in the while loop here as it seems to only
care when jiffies is gone up.

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