On Mon, Feb 26, 2024 at 09:13:35PM -0800, SeongJae Park wrote: > Patch series "mm/damon: fix quota status loss due to online tunings". > > DAMON_RECLAIM and DAMON_LRU_SORT is not preserving internal quota status > when applying new user parameters, and hence could cause temporal quota > accuracy degradation. Fix it by preserving the status. > > This patch (of 2): > > For online parameters change, DAMON_RECLAIM creates new scheme based on > latest values of the parameters and replaces the old scheme with the new > one. When creating it, the internal status of the quota of the old > scheme is not preserved. As a result, charging of the quota starts from > zero after the online tuning. The data that collected to estimate the > throughput of the scheme's action is also reset, and therefore the > estimation should start from the scratch again. Because the throughput > estimation is being used to convert the time quota to the effective size > quota, this could result in temporal time quota inaccuracy. It would be > recovered over time, though. In short, the quota accuracy could be > temporarily degraded after online parameters update. > > Fix the problem by checking the case and copying the internal fields for > the status. > > Link: https://lkml.kernel.org/r/20240216194025.9207-1-sj@xxxxxxxxxx > Link: https://lkml.kernel.org/r/20240216194025.9207-2-sj@xxxxxxxxxx > Fixes: e035c280f6df ("mm/damon/reclaim: support online inputs update") > Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> [5.19+] > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > (cherry picked from commit 1b0ca4e4ff10a2c8402e2cf70132c683e1c772e4) > --- > mm/damon/reclaim.c | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > Now queued up, thanks. greg k-h
