On Wed, January 13, 2021 2:15 PM (JST), Amit Kapila wrote: > On Wed, Jan 13, 2021 at 7:39 AM Kyotaro Horiguchi > <horikyota....@gmail.com> wrote: > > > > At Tue, 12 Jan 2021 08:49:53 +0530, Amit Kapila > > <amit.kapil...@gmail.com> wrote in > > > On Fri, Jan 8, 2021 at 7:03 AM Kyotaro Horiguchi > > > <horikyota....@gmail.com> wrote: > > > > > > > > At Thu, 7 Jan 2021 09:25:22 +0000, "k.jami...@fujitsu.com" > <k.jami...@fujitsu.com> wrote in: > > > > > > Thanks for the detailed tests. NBuffers/32 seems like an > > > > > > appropriate value for the threshold based on these results. I > > > > > > would like to slightly modify part of the commit message in > > > > > > the first patch as below [1], otherwise, I am fine with the > > > > > > changes. Unless you or anyone else has any more comments, I am > > > > > > planning to push the 0001 and 0002 sometime next week. > > > > > > > > > > > > [1] > > > > > > "The recovery path of DropRelFileNodeBuffers() is optimized so > > > > > > that scanning of the whole buffer pool can be avoided when the > > > > > > number of blocks to be truncated in a relation is below a > > > > > > certain threshold. For such cases, we find the buffers by doing > lookups in BufMapping table. > > > > > > This improves the performance by more than 100 times in many > > > > > > cases when several small tables (tested with 1000 relations) > > > > > > are truncated and where the server is configured with a large > > > > > > value of shared buffers (greater than 100GB)." > > > > > > > > > > Thank you for taking a look at the results of the tests. And > > > > > it's also consistent with the results from Tang too. > > > > > The commit message LGTM. > > > > > > > > +1. > > > > > > > > > > I have pushed the 0001. > > > > Thank you for commiting this. > > > > Pushed 0002 as well. >
Thank you very much for committing those two patches, and for everyone here who contributed in the simplifying the approaches, code reviews, testing, etc. I compile with the --enable-coverage and check if the newly-added code and updated parts were covered by tests. Yes, the lines were hit including the updated lines of DropRelFileNodeBuffers(), DropRelFileNodesAllBuffers(), smgrdounlinkall(), smgrnblocks(). Newly added APIs were covered too: FindAndDropRelFileNodeBuffers() and smgrnblocks_cached(). However, the parts where UnlockBufHdr(bufHdr, buf_state); is called is not hit. But I noticed that exists as well in previously existing functions in bufmgr.c. Thank you very much again. Regards, Kirk Jamison