Ubuntu
linux package

  1. Bug #1898786
  2. Comment #6

Comment 6 for bug 1898786

Revision history for this message
Benjamin Allot (ballot) wrote : Re: Issue with bcache bch_mca_scan causing huge IO wait

Here is a trace of the bcache event related lock in the kernel obtained with some bpfcc-tools.

klockstat-bpfcc -c bch_ -i 5 -s 3

The trace has been run in parallel with the following command line

echo "Shrinker disabled: $(date)"; sleep 60; echo "Enabling shrinker: $(date)"; echo 0 | sudo tee /sys/block/bcache0/bcache/cache/internal/btree_shrinker_disabled ; sleep 60; echo "Disabling shrinker: $(date)"; echo 1 | sudo tee /sys/block/bcache0/bcache/cache/internal/btree_shrinker_disabled; sleep 60; echo "End of test: $(date)"

The log are here : https://pastebin.canonical.com/p/jVKdbV3RrK/