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author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2011-02-21 18:55:32 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2011-02-23 11:33:56 +0100 |
commit | cc57aa8f4b3bece8c26c7929728edcc5fa6b5aed (patch) | |
tree | 476c6d4b2d1e2d2cc77c35a8066c284877c7b5b3 /kernel/sched_fair.c | |
parent | c186fafe9aba87c1a93df8c7120a6ae01fe435ad (diff) | |
download | linux-cc57aa8f4b3bece8c26c7929728edcc5fa6b5aed.tar.bz2 |
sched: Clean up some f_b_g() comments
The existing comment tends to grow state (as it already has), split it
up and place it near the actual tests.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nikhil Rao <ncrao@google.com>
Cc: Venkatesh Pallipadi <venki@google.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_fair.c')
-rw-r--r-- | kernel/sched_fair.c | 28 |
1 files changed, 13 insertions, 15 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index cd18600a8a63..03496ebc4553 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -3113,19 +3113,9 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, */ update_sd_lb_stats(sd, this_cpu, idle, cpus, balance, &sds); - /* Cases where imbalance does not exist from POV of this_cpu */ - /* 1) this_cpu is not the appropriate cpu to perform load balancing - * at this level. - * 2) There is no busy sibling group to pull from. - * 3) This group is the busiest group. - * 4) This group is more busy than the avg busieness at this - * sched_domain. - * 5) The imbalance is within the specified limit. - * - * Note: when doing newidle balance, if the local group has excess - * capacity (i.e. nr_running < group_capacity) and the busiest group - * does not have any capacity, we force a load balance to pull tasks - * to the local group. In this case, we skip past checks 3, 4 and 5. + /* + * this_cpu is not the appropriate cpu to perform load balancing at + * this level. */ if (!(*balance)) goto ret; @@ -3134,19 +3124,27 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, check_asym_packing(sd, &sds, this_cpu, imbalance)) return sds.busiest; + /* There is no busy sibling group to pull tasks from */ if (!sds.busiest || sds.busiest_nr_running == 0) goto out_balanced; - /* SD_BALANCE_NEWIDLE trumps SMP nice when underutilized */ + /* SD_BALANCE_NEWIDLE trumps SMP nice when underutilized */ if (idle == CPU_NEWLY_IDLE && sds.this_has_capacity && !sds.busiest_has_capacity) goto force_balance; + /* + * If the local group is more busy than the selected busiest group + * don't try and pull any tasks. + */ if (sds.this_load >= sds.max_load) goto out_balanced; + /* + * Don't pull any tasks if this group is already above the domain + * average load. + */ sds.avg_load = (SCHED_LOAD_SCALE * sds.total_load) / sds.total_pwr; - if (sds.this_load >= sds.avg_load) goto out_balanced; |