15.12.2011 15:48, Jeremy Chadwick wrote:
I'm getting to the point where I'm considering formulating a private mail to Jeff Roberson, requesting that he be aware of the discussion that's happening (not that he necessarily follow or read it), and that based on what I can tell we're at a roadblock -- nobody so far is absolutely certain how to "benchmark" and compare ULE vs. 4BSD in multiple ways, so that those of us involved here can run such utilities and provide the data somewhere central for devs to review. I only mention this because so far I haven't seen anyone really say "okay, this is what we should be using for these kinds of tests". Yay nature of the beast.
I'll try to summarize and propose a test scenario. I don't know whether this helps or not.
We should have two different task types for this one. The first would be Super Affine tasks. They should use few to none syscalls, use medium math, have low memory footprint. No syscalls means this tasks will never stop for memory/disk or other activity so each time the queue is looked upon this task will be ready to run. Medium math means this shouldn't be just a simple big loop so that processor will really compute something with this data. Low memory footprint means this task can reside with data on CPU L1 cache for eons. I'm not sure about branch prediction, should it be distorted or not...
The other task type would be Worker. It doesn't matter what it does but it agressively uses syscalls like working with files/directories.
There should be at least one SA-task per core and at least 10 (?) W-tasks per core.
-- Sphinx of black quartz judge my vow. _______________________________________________ freebsd-performance@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-performance To unsubscribe, send any mail to "freebsd-performance-unsubscr...@freebsd.org"
