W dniu 18.10.2016 o 15:04, Kent Overstreet pisze: > On Tue, Oct 18, 2016 at 02:51:11PM +0200, Marcin Mirosław wrote: >> W dniu 18.10.2016 o 14:45, Kent Overstreet pisze: >>> The issue is that right now btree node coalescing is only run as a batch pass >>> when mark and sweep GC runs (it has nothing to do with GC, it just runs at the >>> same time in the current code). At some point we need to come up with a good way >>> of triggering it as needed. >>> >>> Try triggering a gc, and then check mount time: >>> >>> echo 1 > /sys/fs/bcache/<uuid>/internal/trigger_gc >> >> No change: >> [ 8417.101640] bcache (dm-12): starting mark and sweep: >> [ 8433.795575] bcache (dm-12): mark and sweep done >> [ 8433.795842] bcache (dm-12): starting journal replay: >> [ 8433.796064] bcache (dm-12): journal replay done, 129 keys in 90 >> entries, seq 28581 >> [ 8433.796075] bcache (dm-12): journal replay done >> [ 8433.796076] bcache (dm-12): starting fs gc: >> [ 8433.799493] bcache (dm-12): fs gc done >> [ 8433.799495] bcache (dm-12): starting fsck: >> [ 8433.800613] bcache (dm-12): fsck done >> >> >> /dev/mapper/system10-bcache 9,8G 421M 9,4G 5% /mnt/test > > Bleh. > > Can you check how many nodes are in each btree, post coalescing? > > grep -c ^l /sys/kernel/debug/bcache/<uuid>/*-formats > > Coalescing will also just skip running if the allocator doesn't have enough new > nodes ready to go, rather than block on the allocator thread with locks held - > you can try running it a few times, and see if it's making any progress > shrinking the btrees. No change after a few run, I've got constant values: /sys/kernel/debug/bcache/61fc20db-d626-4f0d-bb33-31a4d998f6df/dirents-formats:1044 /sys/kernel/debug/bcache/61fc20db-d626-4f0d-bb33-31a4d998f6df/extents-formats:1 /sys/kernel/debug/bcache/61fc20db-d626-4f0d-bb33-31a4d998f6df/inodes-formats:2320 /sys/kernel/debug/bcache/61fc20db-d626-4f0d-bb33-31a4d998f6df/xattrs-formats:1 -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
