[concurrency-interest] Some interesting (confusing?) benchmark results
aleksey.shipilev at oracle.com
Tue Feb 12 16:24:51 EST 2013
On 02/13/2013 01:18 AM, √iktor Ҡlang wrote:
> On Tue, Feb 12, 2013 at 8:28 PM, Kirk Pepperdine <kirk at kodewerk.com
> <mailto:kirk at kodewerk.com>> wrote:
> > Do you agree that thread pool sizing depends on type of work? (IO
> bound vs CPU bound, bursty vs steady etc etc)
> > Do you agree that a JVM Thread is not a unit of parallelism?
> > Do you agree that having more JVM Threads than hardware threads is
> bad for CPU-bound workloads?
> No, even with CPU bound workloads I have found that the hardware/OS
> is much better at managing many workloads across many threads than I
> am. So a few more threads is ok, many more threads is bad fast.
> That's an interesting observation. Have any more data on that? (really
> As I said earlier, for CPU-bound workloads we've seen the best
> performance when only loading 60-70% of the cores (other threads exist
> on the machine of course).
I could relate to this observation if "performance" in Viktor's
statement has the significant "latency" component. "pure throughput"
things indeed have the behavior Kirk mentions.
More information about the Concurrency-interest