Re: [PATCH] uprobes: reduce contention on uprobes_tree access

[Jonthan Haslam]

Hi Ingo,

> > This change has been tested against production workloads that exhibit
> > significant contention on the spinlock and an almost order of magnitude
> > reduction for mean uprobe execution time is observed (28 -> 3.5 microsecs).
> 
> Have you considered/measured per-CPU RW semaphores?

No I hadn't but thanks hugely for suggesting it! In initial measurements
it seems to be between 20-100% faster than the RW spinlocks! Apologies for
all the exclamation marks but I'm very excited. I'll do some more testing
tomorrow but so far it's looking very good.

Thanks again for the input.

Jon.