Red Hat Bugzilla – Bug 861934
Severe btrfs performance issue (intermittent)
Last modified: 2015-05-17 21:40:30 EDT
Description of problem:
Often throughout the day, I will see spikes of I/O activity accompanied by 100% CPU use of one of 'btrfs-cleaner', 'btrfs-endio-wri' or 'btrfs-transacti'.
This will last anywhere from 5 seconds to upwards of two minutes, during which the rest of the system will be mostly unresponsive.
Version-Release number of selected component (if applicable):
kernel-3.6.0-0.rc7.git1.4.fc18.x86_64 (rebuilt in non-debug mode)
Happens at least once an hour with no obvious trigger.
Steps to Reproduce:
1. See above
Very poor performance at random intervals.
The filesystem driver should not render the system useless
I rebuilt the kernel in non-debug mode to rule out that the performance issue was caused there.
With guidance, I am willing to perform debugging steps to identify the cause of this issue.
Additional hardware info: I am using an Intel solid-state disk, model SSDSA2MH080G1 (First-generation, no TRIM support).
sysrq+w when the problem is happening will let me know what's going on and we can go from there.
Is there a trick to getting SysRq to work from Cinnamon? I've tried alt-SysRq-w, ctrl-alt-SysRq-w (on my external keyboard) and the same plus Fn on my laptop keyboard. I've seen no indication that this has done anything except occasionally taking screenshots.
open a terminal and echo w > /proc/sysrq-trigger.
any progress on this ? still reproducible ?
This bug is being closed with INSUFFICIENT_DATA as there has not been a response in 2 weeks. If you are still experiencing this issue, please reopen and attach the relevant data from the latest kernel you are running and any data that might have been requested previously.