R
Richard Banville
Guest
-Bp buffers have an LRU chain per user. These user specific LRU chains are indeed protected by the one LRU latch (the same one that is used for the general buffer pool -B). Additionally -Bp buffers do not honor any lru skips settings. So lots of -Bp users could have contention on the one LRU latch. Obviously. looking at this now, there is room for improvement here to implement object latches where each user's -Bp LRU chain is protected by a user specific LRU object latch. Such a direction was probably not possible when I first implemented this. With one LRU latch per -Bp user there would be much less contention amongst users of -Bp. The LRU latch would still be used to move buffers out of the private LRU to the general LRU when access to the same buffer is requested by a different user or if an update were to be made on a buffer in the users -Bp. I would not expect this LRU contention should not be affecting -B access since if there is little paging and high lruskips the LRU is rarely accessed for the -B.
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