Re: [RFC] do_execve() perf improvement opportunity?

From: Rik van Riel
Date: Tue Jun 21 2005 - 09:03:49 EST


On Tue, 21 Jun 2005 cutaway@xxxxxxxxxxxxx wrote:

> I'm thinking it may be possible to very cheaply cache a pointer to the
> last allocation here rather than freeing it and just recycle it for the
> next exec saving a trip through the slab machanism.

Note that the slab mechanism can do allocations locally
on each CPU in an SMP system, while your pointer would
need some cross-CPU synchronisation. Also, you could
end up using the bprm from a CPU on a remote NUMA node,
instead of a local piece of memory.

Still, it would be interesting/educational to know if your
optimisation makes a difference on single CPU systems.

--
The Theory of Escalating Commitment: "The cost of continuing mistakes is
borne by others, while the cost of admitting mistakes is borne by yourself."
-- Joseph Stiglitz, Nobel Laureate in Economics
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