Messages in this thread | | | Date | Thu, 23 Oct 2008 09:12:32 -0500 | From | Robin Holt <> | Subject | Re: [PATCH 0/2] enable irqs when waiting for rwlocks |
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On Wed, Oct 22, 2008 at 10:31:53AM -0700, Rick Jones wrote: > Petr Tesarik wrote: >> Hello, >> >> SGI has observed that on large systems, interrupts are not serviced for >> a long period of time when waiting for a rwlock. The following patch >> series re-enables irqs while waiting for the lock, resembling the code >> which is already there for spinlocks. > > Perhaps I'm just out in left field, but that (and the similar behaviour > for obtaining a spinlock?) feels like treating a symptom rather than a > root cause where the root cause would appear to be long lock hold > times/contention?
Sometimes lock contention on large systems will take a few seconds to pass. This is normal behavior which simply can not be eliminated. For those cases, we need to rely upon being able to re-enable interrupts and allowing other operations to continue normally. Simply put, in some cases, nothing more can be done.
Thanks, Robin
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