Re: [RFC PATCH 0/1] Large folios in block buffered IO path

Bharata B Rao
2024-11-28T04:37:44Z

On 28-Nov-24 9:52 AM, Matthew Wilcox wrote:
> On Thu, Nov 28, 2024 at 09:31:50AM +0530, Bharata B Rao wrote:
>> However a point of concern is that FIO bandwidth comes down drastically
>> after the change.
>>
>> default inode_lock-fix
>> rw=30%
>> Instance 1 r=55.7GiB/s,w=23.9GiB/s r=9616MiB/s,w=4121MiB/s
>> Instance 2 r=38.5GiB/s,w=16.5GiB/s r=8482MiB/s,w=3635MiB/s
>> Instance 3 r=37.5GiB/s,w=16.1GiB/s r=8609MiB/s,w=3690MiB/s
>> Instance 4 r=37.4GiB/s,w=16.0GiB/s r=8486MiB/s,w=3637MiB/s
>
> Something this dramatic usually only happens when you enable a debugging
> option. Can you recheck that you're running both A and B with the same
> debugging options both compiled in, and enabled?

It is the same kernel tree with and w/o Mateusz's inode_lock changes to
block/fops.c. I see the config remains same for both the builds.

Let me get a run for both base and patched case w/o running perf lock
contention to check if that makes a difference.

Regards,
Bharata.