Re: Task watchers v2

From: Paul Jackson
Date: Tue Dec 19 2006 - 07:27:12 EST


Matt wrote:
> Previous iterations of task watchers would prevent the code in these
> paths from being inlined. Furthermore, the code certainly wouldn't be
> placed near the table of function pointers (which was in an entirely
> different ELF section). By placing them adjacent to each other in the
> same ELF section we can improve the likelihood of cache hits in
> fork-heavy workloads (which were the ones that showed a performance
> decrease in the previous iteration of these patches).

Ah so - by marking some of the fork (and exit, exec, ...) routines
with the WATCH_TASK_* mechanism, you can compact them together in the
kernel's text pages, instead of having them scattered about based on
whatever source files they are in.

Nice.

--
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <pj@xxxxxxx> 1.925.600.0401
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