fio config:
bs=4096, iodepth=128, numjobs=10, cpus_allowed_policy=split, rw=read,
ioscheduler=none
Before:
7130K
After:
7630K
So a +7% IOPS gain.
What does the comparison run on a non-NUMA non-shared queue look like?
Because I bet it'd be slower.
To be honest, I don't like this approach at all. It makes the normal
case quite a bit slower by having an extra layer of indirection for the
word, that's quite a bit of extra cost.
It doesn't seem like a good
approach for the issue, as it pessimizes the normal fast case.
Spreading the memory out does probably make sense, but we need to retain
the fast normal case. Making sbitmap support both, selected at init
time, would be far more likely to be acceptable imho.