Re: [PATCH v2 8/8] ext4: enable large folio for regular file

Theodore Ts'o
2025-06-26T14:57:41Z

On Thu, Jun 26, 2025 at 09:26:41PM +0800, Zhang Yi wrote:
>
> Thanks for the report, I will try to reproduce this performance regression on
> my machine and find out what caused this regression.

I took a quick look at this, and I *think* it's because lmbench is
measuring the latency of mmap read's --- I'm going to guess 4k random
page faults, but I'm not sure. If that's the case, this may just be a
natural result of using large folios, and the tradeoff of optimizing
for large reads versus small page faults.

But if you could take a closer look, that would be great, thanks!

- Ted