On Mon, 12 Jun 2006, Andi Kleen wrote:
> > #define __get_cpu_var(var) (*RELOC_HIDE(&per_cpu__##var, __my_cpu_offset()))
>
> It is also affected by your race. The inc would only be atomic if the counter
> was in the PDA, but standard per cpu data isn't. So it has to follow
> a pointer and then it could already have switched.
I thought the above would refer to a PDA memory area that is specially
mapped by each processor? That is the only thing that would get this
working right because we would map to a different PDA if the process
would be mapped to a different processor.
> Fix would be to disable preemption. I don't think it needs cli/sti
> on non preemptible kernels.
Yuck. The advantage of local.t was that it does not need any of these
tricks. What is the point of local.t if one needs to disable preemption?
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
