Re: PATCH: sleeping while holding a lock in _pagebuf_free_bh()::page_buf.c

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

On Tue, Oct 22, 2002 at 03:55:43PM -0400, Luben Tuikov wrote:
> This is what wake_up_sync() does. wake_up() may reschedule
> on an SMP system, since the other CPUs may be able to get
> another task to run. This is why there are two different
> implementations wake_up() and wake_up_sync().
> 
> If you have 4 CPUs, 3 idle and call wake_up() why should
> the 3 idle CPUs _STAY_ idle, _until_ you (later) call schedule()
> and _then_ to schedule another task on the idle CPUs, and
> you to continue to go on, say if you were a SCHED_FIFO, or
> SCHED_OTHER...
> 
> BTW, that the _whole_ point of SMP -- _symmetric_ MP.

Could you please give me some of thev crack you're smoking?

I'd suggest you take an actual look at the implementation
of wake_up/wake_up_sync.