tree e222b2238ed691ced6eaeb47733f7e4c2b9a3c37
parent 649027d73a6309ac34dc2886362e662bd73456dc
author Tejun Heo <tj@kernel.org> 1277798835 +0200
committer Tejun Heo <tj@kernel.org> 1277798835 +0200

workqueue: implement cpu intensive workqueue

This patch implements cpu intensive workqueue which can be specified
with WQ_CPU_INTENSIVE flag on creation.  Works queued to a cpu
intensive workqueue don't participate in concurrency management.  IOW,
it doesn't contribute to gcwq->nr_running and thus doesn't delay
excution of other works.

Note that although cpu intensive works won't delay other works, they
can be delayed by other works.  Combine with WQ_HIGHPRI to avoid being
delayed by other works too.

As the name suggests this is useful when using workqueue for cpu
intensive works.  Workers executing cpu intensive works are not
considered for workqueue concurrency management and left for the
scheduler to manage.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>