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sched: Change rq->nr_running to unsigned int

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Since there's a PID space limit of 30bits (see
futex.h:FUTEX_TID_MASK) and allocating that many tasks (assuming a
lower bound of 2 pages per task) would still take 8T of memory it
seems reasonable to say that unsigned int is sufficient for
rq->nr_running.

When we do get anywhere near that amount of tasks I suspect other
things would go funny, load-balancer load computations would really
need to be hoisted to 128bit etc.

So save a few bytes and convert rq->nr_running and friends to
unsigned int.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-y3tvyszjdmbibade5bw8zl81@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra
2012-04-26 13:12:27 +02:00
committed by Ingo Molnar
parent ad7687dde8
commit c82513e513
3 changed files with 8 additions and 8 deletions
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8
kernel/sched/fair.c
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@@ -4447,10 +4447,10 @@ redo:
* correctly treated as an imbalance.
*/
env.flags |= LBF_ALL_PINNED;
env.load_move = imbalance;
env.src_cpu = busiest->cpu;
env.src_rq = busiest;
env.loop_max = min_t(unsigned long, sysctl_sched_nr_migrate, busiest->nr_running);
env.load_move = imbalance;
env.src_cpu = busiest->cpu;
env.src_rq = busiest;
env.loop_max = min(sysctl_sched_nr_migrate, busiest->nr_running);
more_balance:
local_irq_save(flags);