Re: [linus:master] [btrfs] 52bb7a2166: filebench.sum_operations/s -4.0% regression

From: David Sterba
Date: Tue May 02 2023 - 12:33:34 EST


On Sat, Apr 29, 2023 at 10:29:00PM +0800, kernel test robot wrote:
>
> Hello,
>
> kernel test robot noticed a -4.0% regression of filebench.sum_operations/s on:
>
>
> commit: 52bb7a2166af490317ce2cca1865b6630e86aca8 ("btrfs: introduce size class to block group allocator")
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master

The size classes are a heuristic, it may improve and worsen some
workloads and also depends on actual layout of extents and block groups.
So this is expected, -4% is within acceptable range.