On Thu, 7 Dec 2023 17:14:22 -0800 Nhat Pham <nphamcs@xxxxxxxxx> wrote: > > I don't have any concrete numbers though - any numbers I can pull out > > are from highly artificial tasks that only serve to test the > > correctness aspect of the implementation. zswap.writeback disablement > > would of course be faster in these situations (up to 33%!!!!) - but > > that's basically just saying HDD is slow. Which is not very > > informative or surprising, so I did not include it in the changelog. > > For instance, on a server with HDD, I allocate memories and populate > them with random values (so that zswap store will always fail), and > specify memory.high low enough to trigger reclaim. The time it takes > to allocate the memories and just read through it a couple of times > (doing silly things like computing the values' average etc.): > > zswap.writeback disabled: > real 0m30.537s > user 0m23.687s > sys 0m6.637s > 0 pages swapped in > 0 pages swapped out > > zswap.writeback enabled: > real 0m45.061s > user 0m24.310s > sys 0m8.892s > 712686 pages swapped in > 461093 pages swapped out > > (the last two lines are from vmstat -s). I pasted that also.
