Messages in this thread | | | Date | Tue, 24 Feb 2015 16:58:26 +0100 | From | Daniel Wagner <> | Subject | Re: [RFC v1 0/5] fs/locks: Use plain percpu spinlocks instead of lglock to protect file_lock |
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On 02/20/2015 05:05 PM, Andi Kleen wrote: > Daniel Wagner <daniel.wagner@bmw-carit.de> writes: >> >> I am looking at how to get rid of lglock. Reason being -rt is not too >> happy with that lock, especially that it uses arch_spinlock_t and > > AFAIK it could just use normal spinlock. Have you tried that?
I have tried it. At least fs/locks.c didn't blow up. The benchmark results (lockperf) indicated that using normal spinlocks is even slightly faster. Simply converting felt like cheating. It might be necessary for the other user (kernel/stop_machine.c). Currently it looks like there is some additional benefit getting lglock away in fs/locks.c.
cheers, daniel
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