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| author | Tejun Heo <tj@kernel.org> | 2010-08-01 11:50:12 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2010-08-01 11:50:12 +0200 |
| commit | 098849516dd522a343e659740c8f1394a5b7fa69 (patch) | |
| tree | 46e902aabf3734c68173e959735ee75760b9f911 /kernel | |
| parent | 40f2b6ffe525e975203c1621d4d4abaa7689b674 (diff) | |
| download | lwn-098849516dd522a343e659740c8f1394a5b7fa69.tar.gz lwn-098849516dd522a343e659740c8f1394a5b7fa69.zip | |
workqueue: explain for_each_*cwq_cpu() iterators
for_each_*cwq_cpu() are similar to regular CPU iterators except that
it also considers the pseudo CPU number used for unbound workqueues.
Explain them.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/workqueue.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index e5cb7faac58e..1105c474073a 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -271,6 +271,19 @@ static inline int __next_wq_cpu(int cpu, const struct cpumask *mask, return __next_gcwq_cpu(cpu, mask, !(wq->flags & WQ_UNBOUND) ? 1 : 2); } +/* + * CPU iterators + * + * An extra gcwq is defined for an invalid cpu number + * (WORK_CPU_UNBOUND) to host workqueues which are not bound to any + * specific CPU. The following iterators are similar to + * for_each_*_cpu() iterators but also considers the unbound gcwq. + * + * for_each_gcwq_cpu() : possible CPUs + WORK_CPU_UNBOUND + * for_each_online_gcwq_cpu() : online CPUs + WORK_CPU_UNBOUND + * for_each_cwq_cpu() : possible CPUs for bound workqueues, + * WORK_CPU_UNBOUND for unbound workqueues + */ #define for_each_gcwq_cpu(cpu) \ for ((cpu) = __next_gcwq_cpu(-1, cpu_possible_mask, 3); \ (cpu) < WORK_CPU_NONE; \ |