On 08/28/2012 03:04 AM, Tejun Heo wrote: > Hello, Lai. > > On Tue, Aug 28, 2012 at 01:58:24AM +0800, Lai Jiangshan wrote: >> busy_worker_rebind_fn() can't return until all idle workers are rebound, >> the code of busy_worker_rebind_fn() ensure this. >> >> So we can change the order of the code of rebind_workers(), >> and make it a single pass do the rebind_workers(). >> >> It makes the code much clean and better readability. > > I can't see how this could be correct.
Could you elaborate more why it is not correct. > What prevents busy worker from > grabbing manager_mutex before idle one? > busy worker still has WORKER_REBIND when it enter busy_worker_rebind_fn(), so it can sleep(include grab the manager_mutex). When this mutex_lock() returns, it means rebind_workers() are done which means all idle are rebound and can be locally woken up. So busy worker can return from busy_worker_rebind_fn() and handle other possible-sleeping items. If the CPU is offline again, the busy worker has WORKER_UNBOUND, it is also correct when it returns from busy_worker_rebind_fn(). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
