Messages in this thread | | | From | "Ghannam, Yazen" <> | Subject | RE: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID | Date | Thu, 2 Feb 2017 16:14:54 +0000 |
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> -----Original Message----- > From: Borislav Petkov [mailto:bp@alien8.de] > Sent: Thursday, February 2, 2017 7:11 AM > > Context switches have dropped, cache misses are the same and we have a > rise in cpu-migrations. That last bit is interesting and I don't have an > answer yet. Maybe peterz has an idea. >
Could it be that the scheduler is more lax about migrations between SMT siblings?
> Cycles have dropped too. > > And we're 6 secs faster so I'll take that. > > Now on to run the same thing on a bigger bulldozer. >
Here are my results on a 32C Bulldozer system with an SSD. Also, I use ccache so I added "ccache -C" in the pre-build script so the cache gets cleared.
Before: Performance counter stats for 'make -s -j65 bzImage' (3 runs):
2375752.777479 task-clock (msec) # 23.589 CPUs utilized ( +- 0.35% ) 1,198,979 context-switches # 0.505 K/sec ( +- 0.34% ) 8,964,671,259 cache-misses ( +- 0.44% ) 79,399 cpu-migrations # 0.033 K/sec ( +- 1.92% ) 37,840,875 page-faults # 0.016 M/sec ( +- 0.20% ) 5,425,612,846,538 cycles # 2.284 GHz ( +- 0.36% ) 3,367,750,745,825 instructions # 0.62 insn per cycle ( +- 0.11% ) 750,591,286,261 branches # 315.938 M/sec ( +- 0.11% ) 43,544,059,077 branch-misses # 5.80% of all branches ( +- 0.08% )
100.716043494 seconds time elapsed ( +- 1.97% )
After: Performance counter stats for 'make -s -j65 bzImage' (3 runs):
1736720.488346 task-clock (msec) # 23.529 CPUs utilized ( +- 0.16% ) 1,144,737 context-switches # 0.659 K/sec ( +- 0.20% ) 8,570,352,975 cache-misses ( +- 0.33% ) 91,817 cpu-migrations # 0.053 K/sec ( +- 1.67% ) 37,688,118 page-faults # 0.022 M/sec ( +- 0.03% ) 5,547,082,899,245 cycles # 3.194 GHz ( +- 0.19% ) 3,363,365,420,405 instructions # 0.61 insn per cycle ( +- 0.00% ) 749,676,420,820 branches # 431.662 M/sec ( +- 0.00% ) 43,243,046,270 branch-misses # 5.77% of all branches ( +- 0.01% )
73.810517234 seconds time elapsed ( +- 0.02% )
Thanks, Yazen
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