On 9/16/20 8:57 AM, Li, Aubrey wrote:
Here are the uperf results of the various patchsets. Note, that disabling smt
is better for these tests and that that presumably reflects the overall
overhead of core scheduling which went from bad to really bad. The primary
focus in this email is to start to understand what happened within core sched
itself.
patchset smt=on/cs=off smt=off smt=on/cs=on
--------------------------------------------------------
v5-v5.6.y : 1.78Gb/s 1.57Gb/s 1.07Gb/s
pre-v6-v5.6.y : 1.75Gb/s 1.55Gb/s 822.16Mb/s
v6-5.7 : 1.87Gs/s 1.56Gb/s 561.6Mb/s
v6-5.7-hotplug : 1.75Gb/s 1.58Gb/s 438.21Mb/s
v7 : 1.80Gb/s 1.61Gb/s 440.44Mb/s
I haven't had a chance to play with v7, but I got something different.
branch smt=on/cs=on
coresched/v5-v5.6.y 1.09Gb/s
coresched/v6-v5.7.y 1.05Gb/s
I attached my kernel config in case you want to make a comparison, or you
can send yours, I'll try to see I can replicate your result.
I will give this config a try. One of the reports forwarded to me about the drop in uperf perf was an email from you I
believe mentioning a 50% perf drop between v5 and v6?? I was actually setting out to duplicate your results. :-)
-chrish
