Messages in this thread | | | From | David Decotigny <> | Date | Wed, 2 Jan 2013 12:34:09 -0800 | Subject | Re: [PATCH v3] lib: cpu_rmap: avoid flushing all workqueues |
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Thanks,
I appreciate your review and clarification, as I was afraid there could be something I missed. I will send v4 of this patch: an update with the cpu_rmap_get helper that Josh suggested and the "free_cpu_rmap" alias removed.
Regards,
-- David Decotigny
On Wed, Jan 2, 2013 at 12:29 PM, Ben Hutchings <bhutchings@solarflare.com> wrote: > On Sat, 2012-12-29 at 12:36 -0800, Josh Triplett wrote: >> 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@googlers.com> >> >> 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. > > I intended to make cpu_rmap usable independently of IRQ notification, > although as you note there have been no other users so far. > free_cpu_rmap() is now effectively an alias for cpu_rmap_put(), and the > latter *does* have a caller. So perhaps cpu_rmap_put() should be extern > and the alias dropped. > > Ben. > > -- > Ben Hutchings, Staff Engineer, Solarflare > Not speaking for my employer; that's the marketing department's job. > They asked us to note that Solarflare product names are trademarked. >
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