Re: [patch 0/8] mutex subsystem, ANNOUNCE

[Nick Piggin <nickpiggin@yahoo.com.au>]

Jes Sorensen wrote:
>>>>>>"Ingo" == Ingo Molnar <mingo@elte.hu> writes:
> 
> 
> Ingo> this is the latest version of the mutex subsystem
> Ingo> patch-queue. It consists of the following patches:
> 
> [snip]
> 
> Ingo> the patches are against Linus' latest tree, and were tested on
> Ingo> i386, x86_64 and ia64. [the tests were also done in
> Ingo> DEBUG_MUTEX_FULL mode, to make sure the code works
> Ingo> fine. MUTEX_FULL support is not included in this patchqueue].
> 
> Hi,
> 
> I have been working with Ingo on porting this to ehe ia64 and run a
> bunch of benchmarks using the DEBUG_MUTEX_FULL settings to see how it
> behaves on various sized systems (8, 24 and 60 CPUs). In general I am
> seeing speedups of roughly a factor 4 on XFS and 2.4 on TMPFS.
> 
> Below you will find the results. It's basically the same kernel
> version with and without the mutex patch running in DEBUG_MUTEX_FULL
> mode without debugging enabled. No other config options were changed.
> 
> I won't rule out any pilot errors, but at least it gives an idea about
> the change in performance for a specific workload on different sized
> boxes.
> 

It would be nice to first do a run with a fair implementation of
mutexes.

The improvements are definitely large enough that you cannot dismiss
the unfair implementation... I wonder if you can record a maximum
cost per op? That would be more interesting than either average or
standard deviation.

Thanks,
Nick

-- 
SUSE Labs, Novell Inc.

Send instant messages to your online friends http://au.messenger.yahoo.com