Re: [PATCH v3] lib: cpu_rmap: avoid flushing all workqueues

[Josh Triplett]

On Sat, Dec 29, 2012 at 11:57:09AM -0800, David Decotigny wrote:
> In some cases, free_irq_cpu_rmap() is called while holding a lock
> (eg. rtnl). This can lead to deadlocks, because it invokes
> flush_scheduled_work() which ends up waiting for whole system
> workqueue to flush, but some pending works might try to acquire the
> lock we are already holding.
> 
> This commit uses reference-counting to replace
> irq_run_affinity_notifiers(). It also removes
> irq_run_affinity_notifiers() altogether.
> 
> Signed-off-by: David Decotigny <decot@xxxxxxxxxxxx>

You might consider adding a cpu_rmap_get to parallel cpu_rmap_put.

Also, why keep free_cpu_rmap around at this point?  As far as I can
tell, it has no callers.

Otherwise, this looks good to me.

- Josh Triplett
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/