Re: Task watchers v2

[Paul Jackson <pj@sgi.com>]

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.

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                  Paul Jackson <pj@sgi.com> 1.925.600.0401