[patch 0/2] sched,timers: simplify calc_load and avoid cpu iteration loop

From: Thomas Gleixner
Date: Thu May 14 2009 - 07:22:47 EST


Dimitri Sivanich pointed out that calc_load iterates over all online
CPUs under xtime lock which can cause long latencies on large SMP
systems.

The following patch series removes the iteration loop and lets
scheduler_tick() on each CPU update the number of active tasks. The
calc_load() function just uses this variable and updates avenrun from
do_timer().

Dimitri, can you please test run this on one of your large machines ?

Thanks,

tglx


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