Make the lock hash tables fixed-sized This prevents the LOCK table from "stealing" space that was originally calculated for the PROLOCK table, and vice versa. That was weirdly indeterministic so that if you e.g. took a lot of locks consuming all the available shared memory for the LOCK table, subsequent transactions that needed the more space for the PROCLOCK table would fail, but if you restarted the system then the space would be available for PROCLOCK again. Better to be strict and predictable, even though that means that in many cases you can acquire far fewer locks than before.
This also prevents the lock hash tables from using up the general-purpose 100 kB reserve we set aside for "stuff that's too small to bother estimating" in CalculateShmemSize(). We are pretty good at accounting for everything nowadays, so we could probably make that reservation smaller, but I'll leave that for another commit. Reviewed-by: Ashutosh Bapat <[email protected]> Reviewed-by: Matthias van de Meent <[email protected]> Discussion: https://www.postgresql.org/message-id/[email protected] Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/e1ad034809a4628b995ae458d0d56744ca3b5ff3 Modified Files -------------- src/backend/storage/lmgr/lock.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-)
