Revert "[folly] TLS cache for AccessSpreader"
Summary:
This reverts commit
4ebb2303bbcf343d7c2bcc95d55557c0a3b444f3.
The caching mechanism was based on a misunderstanding of the
implementation of CLOCK_MONOTONIC_COARSE, and is not correct.
On the plus side, the upstream kernel patch
e76b027e6408 x86,vdso: Use LSL unconditionally for vgetcpu
gets the vdso getcpu from 16 nanos down to 10 (half of which is the
inherent indirect call).
Test Plan: unit tests
Reviewed By: delong.j@fb.com
Subscribers: trunkagent, bmaurer, tudorb, folly-diffs@, yfeldblum, jdelong
FB internal diff:
D1840690
Signature: t1:
1840690:
1423693026:
33801341ec0b83bf47e050be6528c5dd05021ed5