Andreas Bluemle observed an undesirable behavior in the ceph messenger when using networking hardware that binds received data handling to a single CPU. The messenger uses a workqueue to process message activity, and in this case all work was being queued on the same per-cpu workqueue. Consequently that CPU becomes a bottleneck, forced to process all incoming messages.
Marking the workqueue UNBOUND allows any available CPU to process a work item on the queue. The concurrency of the workqueue will be limited by the number of active connections. Reported-by: Andreas Bluemle <[email protected]> Signed-off-by: Alex Elder <[email protected]> --- net/ceph/messenger.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index 28ed904..f9f65fe 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -190,7 +190,7 @@ int ceph_msgr_init(void) zero_page = ZERO_PAGE(0); page_cache_get(zero_page); - ceph_msgr_wq = alloc_workqueue("ceph-msgr", 0, 0); + ceph_msgr_wq = alloc_workqueue("ceph-msgr", WQ_UNBOUND, 0); if (ceph_msgr_wq) return 0; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
