It examines the blkio device tree and sums data as far as i know. Removed devices do not get deleted from the blkio statistics tree and are just marked as offline somehow.
In our case racadm lclog created and destroyed usb devices to pull data and the blkio tree reached over 65000 leafs. It takes time to process a tree that large. WE believe our issue was caused by accumulation over time of the usb device leafs from racadm lclog. WE had it running in a cron which has now been stopped. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-meta in Ubuntu. https://bugs.launchpad.net/bugs/2021571 Title: cat /sys/fs/cgroup/blkio/blkio.time_recursive took 1second to complete Status in linux-meta package in Ubuntu: Confirmed Bug description: Issue: ```console # time cat /sys/fs/cgroup/blkio/blkio.time_recursive 8:16 354721435 real 0m1.297s user 0m0.000s sys 0m1.297s ``` As could be seen from above result, cat blkio took about 1 second to complete which is much longer than a normal case. Kernel Version: Linux compute08 4.15.0-72-generic #81-Ubuntu SMP Tue Nov 26 12:20:02 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux Would be appreciated to know any operations to identify the issue, Thank you very much for the help. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-meta/+bug/2021571/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
