OPTIM: task: readjust CPU bandwidth distribution since last update
Now that we can more accurately watch which connection is really
being woken up from itself, it was desirable to re-adjust the CPU BW
thresholds based on measurements. New tests with 60000 concurrent
connections were run at 100 Gbps with unbounded queues and showed
the following distribution:
scenario TC0 TC1 TC2 observation
-------------------+---+---+----+---------------------------
TCP conn rate : 32, 51, 17
HTTP conn rate : 34, 41, 25
TCP byte rate : 2, 3, 95 (2 MB objets)
splicing byte rate: 11, 6, 83 (2 MB objets)
H2 10k object : 44, 23, 33 client-limited
mixed traffic : 18, 10, 72 2*1m+1*0: 11kcps, 36 Gbps
The H2 experienced a huge change since it uses a persistent connection
that was accidently flagged in the previous test. The splicing test
exhibits a higher need for short tasklets, so does the mixed traffic
test. Given that latency mainly matters for conn rate and H2 here,
the ratios were readjusted as 33% for TC0, 50% for TC1 and 17% for
TC2, keeping in mind that whatever is not consumed by one class is
automatically shared in equal propertions by the next one(s). This
setting immediately provided a nice improvement as with the default
settings (maxpollevents=200, runqueue-depth=200), the same ratios as
above are still reported, while the time to request "show activity"
on the CLI dropped to 30-50ms. The average loop time is around 5.7ms
on the mixed traffic.
In addition, one extra stress test at 90.5 Gbps with 5100 conn/s shows
70-100ms CLI request time, with an average loop time of 17 ms.
1 file changed