mempool and cacheline ping pong

Hi Mark, While trying to figure out a random failure in the mempool tests[0] introduced when fixing a bug in how mempool selects shards holding the byte count of a given pool[1] earlier this year, I was intrigued by this "cache line ping pong" problem[2]. And I wonder if you have some kind of benchmark, somewhere in your toolbox, that someone could use to demonstrate the problem. Maybe such a code could be adapted to show the benefit of the optimization implemented in mempool? Cheers [0] https://tracker.ceph.com/issues/49781#note-9 [1] https://github.com/ceph/ceph/pull/39057/files [2] https://www.drdobbs.com/parallel/understanding-and-avoiding-memory-issues/2… -- Loïc Dachary, Artisan Logiciel Libre