Hi.
Robert Watson wrote:
Is there any other FreeBSD developer who can take care of performance
problems on many-cores systems? Seems like upcoming 7-RELEASE and
6.3-RELEASE would be completely unusable for us on that kind of
systems i.e. mostly on all modern hardware.
There are many FreeBSD developers who care a great deal about the
performance of many-core systems. However, it's also very late in the
release cycle for 7.0, and this sort of analysis requires a lot of time,
so I don't think we will (or should) see any substantial changes at this
point as they would require us to significantly extend the release cycle
in order to test them properly.
Is there a reason to release system that unable to work on 8-core systems? What
would people think when they won't be able to run their old projects after
moving to the new hardware?
The right path forwawrd at this point
is to diagnosis the problems and work on fixing them in 8-CURRENT, and
assuming they are not highly disruptive, MFC them for FreeBSD 7.1.
I believe at least the bug with lockmgr contention should be fixed before
release.
In general, the most important factor in optimizing performance is to
get a good collaboration going between someone who can reproduce the
problem, ideally in a way that can be shared with developers so they can
also reproduce the problem, and provide testing and feedback over an
extended period (several months) while the changes are developed and
refined. This is part of the role Kris has been playing with a number
of FreeBSD developers -- Jeff, Attilio, myself, etc -- he set up highly
reproduceable performance measurements and then worked with us to
evaluate various patches to improve performance. That kind of dynamic
is invaluable, but it requires users who care a lot about performance
(or whatever other factor it is) to spend a fair amount of time helping
us. Whether this is by providing a potted benchmark for developers to
try out, or if this is by providing access to the test environment on
their own systems, it's still critical.
I know from previous messages in the thread that you can't provide
access to the actual application, but can you provide some sort of
potted substitute that has similar performance properties -- be it php
page sizes, database query load traces that can be replayed, etc?
I can try to produce synthetic benchmarks based on my workload but really I'm
interested more in real workload performance. I'm ready to test changes, measure
differences and provide any benchmark and profiling information. Except for
lockmgr contention bug there seems to be a much optimization work to do because
FreeBSD with patched lockmgr on my workload is still 1.5 times slower that Linux.
With best regards,
Alexey Popov
_______________________________________________
freebsd-stable@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "[EMAIL PROTECTED]"
