[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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



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. 


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.