Messages in this thread | | | Date | Tue, 20 Nov 2012 22:22:58 -0500 | From | Rik van Riel <> | Subject | Re: numa/core regressions fixed - more testers wanted |
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On 11/20/2012 08:54 PM, Andrew Theurer wrote:
> I can confirm single JVM JBB is working well for me. I see a 30% > improvement over autoNUMA. What I can't make sense of is some perf > stats (taken at 80 warehouses on 4 x WST-EX, 512GB memory):
AutoNUMA does not have native THP migration, that may explain some of the difference.
> tips numa/core: > > 5,429,632,865 node-loads > 3,806,419,082 node-load-misses(70.1%) > 2,486,756,884 node-stores > 2,042,557,277 node-store-misses(82.1%) > 2,878,655,372 node-prefetches > 2,201,441,900 node-prefetch-misses > > autoNUMA: > > 4,538,975,144 node-loads > 2,666,374,830 node-load-misses(58.7%) > 2,148,950,354 node-stores > 1,682,942,931 node-store-misses(78.3%) > 2,191,139,475 node-prefetches > 1,633,752,109 node-prefetch-misses > > The percentage of misses is higher for numa/core. I would have expected > the performance increase be due to lower "node-misses", but perhaps I am > misinterpreting the perf data.
Lack of native THP migration may be enough to explain the performance difference, despite autonuma having better node locality.
>> Next I'll work on making multi-JVM more of an improvement, and >> I'll also address any incoming regression reports. > > I have issues with multiple KVM VMs running either JBB or > dbench-in-tmpfs, and I suspect whatever I am seeing is similar to > whatever multi-jvm in baremetal is. What I typically see is no real > convergence of a single node for resource usage for any of the VMs. For > example, when running 8 VMs, 10 vCPUs each, a VM may have the following > resource usage:
This is an issue. I have tried understanding the new local/shared and shared task grouping code, but have not wrapped my mind around that code yet.
I will have to look at that code a few more times, and ask more questions of Ingo and Peter (and maybe ask some of the same questions again - I see that some of my comments were addressed in the next version of the patch, but the email never got a reply).
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