Messages in this thread | | | Date | Tue, 25 Apr 2006 20:30:26 +0200 | From | Jens Axboe <> | Subject | Re: [PATCH] likely cleanup: revert unlikely in ll_back_merge_fn |
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On Tue, Apr 25 2006, Hua Zhong wrote: > With likely/unlikely profiling (see the recent patch dwalker@mvista.com > sent), on my not-so-busy-typical-development system it shows more than > 80K misses and no hits. So I guess it makes sense to revert. > > I don't know BIO code very well, but I hope this data is useful for the > experts.
Well you'd want to optimize for the busy case, right, no point in optimizing for a more idle system.
I'm not at all uninterested in this, I'd just like to see a more intelligent/controlled work load that actually stresses the io subsystem being profiled. If you have a not-so-busy system, you like don't do enough IO to trigger a lot of merges. Or maybe you do, and we just have a bug somewhere so that we unfortunately repeatedly recount segments.
Care to run a simple io benchmark and profile that?
-- Jens Axboe
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