From: Andrew Morton <[email protected]>
Date: Sun, 5 Mar 2006 00:45:34 -0800
> The __get_cpu_var() here will run smp_processor_id() from preemptible
> context. You'll get a big warning if the correct debug options are set.
>
> The reason for this is that preemption could cause this code to hop between
> CPUs.
>
> Please always test code with all debug options enabled and with full kernel
> preemption.
To be fair that warning doesn't trigger on some platforms, such as
sparc64 where the __get_cpu_var() implementation simply takes the
value from a fixed cpu register and doesn't do the debugging check.
Sparc64 should add the check when debugging options are enabled, for
sure, but the point is that it may not entirely be the tester's fault.
:-)
-
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]
