Updated perf backtrace improvement patchkit

[Andi Kleen]

I reworked the patchkit to speed up perf backtracing based on
the feedback. It now uses a new method to determine the kernel
addresses using the page tables, and also avoids using copy_*_user
in the backtrace at all.

The goal is to avoid perf exceeding the NMI handler CPU time quota.

In addition this patchkit also optimizes the generic fault handling
for one case in copy_*_user (running on systems with enhanced copy
string)

Hopefully this version is more acceptable.

-Andi

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/