Avoid acquiring spinlock when checking if recovery has finished, for speed.
RecoveryIsInProgress() can be called very frequently. During normal
operation, it just checks a backend-local variable and returns quickly,
but during hot standby, it checks a spinlock-protected shared variable.
Those spinlock acquisitions can become a point of contention on a busy
hot standby system.
Replace the spinlock acquisition with a memory barrier.
Per discussion with Andres Freund, Ants Aasma and Merlin Moncure.
Branch
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master
Details
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http://git.postgresql.org/pg/commitdiff/1a3d104475ce01326fc00601ed66ac4d658e37e5
Modified Files
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src/backend/access/transam/xlog.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
