Use ISB as a spin-delay instruction on ARM64.
authorTom Lane <tgl@sss.pgh.pa.us>
Wed, 6 Apr 2022 22:57:57 +0000 (18:57 -0400)
committerTom Lane <tgl@sss.pgh.pa.us>
Wed, 6 Apr 2022 22:58:14 +0000 (18:58 -0400)
commita82a5eee314df52f3183cedc0ecbcac7369243b1
tree66b56e90a4483c68930a083534fc1963859464a7
parent8ea7963fc741b6f403a544d56ad0ecf78e5237b1
Use ISB as a spin-delay instruction on ARM64.

This seems beneficial on high-core-count machines, and not harmful
on lesser hardware.  However, older ARM32 gear doesn't have this
instruction, so restrict the patch to ARM64.

Geoffrey Blake

Discussion: https://postgr.es/m/78338F29-9D7F-4DC8-BD71-E9674CE71425@amazon.com
src/include/storage/s_lock.h