On 2023/1/5 06:17, Anand Jain wrote:
On 1/4/23 16:21, Qu Wenruo wrote:We introduced scrub speed throttle in commit eb3b50536642 ("btrfs: scrub: per-device bandwidth control"), but it is not that well documented (e.g. what's the unit of the sysfs interface), nor tested by any test case. This patch will add a test case for this functionality. The test case itself is pretty straightforward: - Fill the fs with 2G file as scrub workload - Set scrub speed limit to 50MiB/s - Scrub and compare the reported rate against above 50MiB/s throttle However the test case has an assumption that the underlying disk must be faster than our 50MiB/s, which should be pretty common in baremetal/exclusive VMs. But for cloud environment it's not ensured 100%, thus the test case is not included in auto group to avoid false alerts.Why not scrub the data twice: first to determine the speed, and then to check if it can be throttled to ~50%?
Sounds great. Thanks, Qu
-Anand
