Jan, ----- Ursprüngliche Mail ----- > Von: "Jan Kara" <jack@xxxxxxx> >> Is this expected? >> Just want to make sure that the said commit didn't uncover an UBIFS issue. > > Yes, I think it is expected. Likely the background threshold for UBIFS bdi > is very small (probably UBIFS is not used much for writeback compared to > other filesystems). Previously, we just used wb_stat() which returned 0 > (PCP counter inexact value) and so background writeback didn't trigger. Now > we use wb_stat_sum() when threshold is small, get exact value of dirty > pages and decide to start background writeback. Thanks for the prompt reply! > The only thing is, whether it is really expected that the threshold for > UBIFS bdi is so small. You can check the values in > /sys/kernel/debug/bdi/<bdi>/stats. BdiDirtyThresh is indeed 0. BdiWriteback: 0 kB BdiReclaimable: 0 kB BdiDirtyThresh: 0 kB DirtyThresh: 772620 kB BackgroundThresh: 385836 kB BdiDirtied: 0 kB BdiWritten: 0 kB BdiWriteBandwidth: 102400 kBps b_dirty: 0 b_io: 0 b_more_io: 0 b_dirty_time: 0 bdi_list: 1 state: 1 Thanks, //richard
