Re: [PATCH] Cpuset: rcu optimization of page alloc hook

Andi Kleen
2005-12-14T04:02:53Z

> But, boy oh boy, that synchronize_rcu() call sure takes it time.
>
> My cpuset torture test was creating, destroying and abusing about 2600
> cpusets/sec before this change, and now it does about 144 cpusets/sec.
>
> That cost 95% of the performance. This only hits on the cost of
> attaching a task to a different cpuset (by writing its <pid> to
> some other cpuset 'tasks' file.)

That is why call_rcu.et.al. is a better interface if you want performance.
It runs the freeing batched in the background.

-Andi