On Friday 11 September 2015 18:50:35 you wrote:
> a) As I said upthread there's a patch to remove these locks entirely
It is very interesting. Could you provide a link? And it's not very good,
since there is a bottleneck PinBuffer / UnpinBuffer instead of LWLocks.
> b) It doesn't matter anyway. Not every pin goes through the buffer
> mapping table. StrategyGetBuffer(), SyncOneBuffer(), ...
StrategyGetBuffer call only from BufferAlloc .
SyncOneBuffer not problem too because:
PinBuffer_Locked(bufHdr);
LWLockAcquire(bufHdr->content_lock, LW_SHARED);
And please read comment before LockBufHdr(bufHdr) in SyncOneBuffer.
We checked all functions with refcount and usage_count.
Thanks! ^_^
--
YUriy Zhuravlev
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
