Hello, We've seen a significant perf degradation when reading a tmpfs file swapped into zram between 5.10 and 5.15. The source of the issue is: * aa48e47e3906: memcg: infrastructure to flush memcg stats There's a couple of commits that helps to bridge the gap in 5.16: * 11192d9c124d: memcg: flush stats only if updated * fd25a9e0e23b: memcg: unify memcg stat flushing Both of these apply cleanly and Shakeel (the author) has okayed the backport from his end. He also suggested backporting the following: * 5b3be698a872: memcg: better bounds on the memcg stats updates I personally did not test this one, but it applies cleanly, so there's probably no harm. I cc'd Shakeel in case you want confirmation on that. It's not a part of any tag yet. Please backport all three (or at least the first two) to 5.15 LTS. Thanks!
