On 28-Nov-24 10:07 AM, Bharata B Rao wrote:

On 28-Nov-24 9:52 AM, Matthew Wilcox wrote:

quoted

On Thu, Nov 28, 2024 at 09:31:50AM +0530, Bharata B Rao wrote:

quoted

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.

Without perf lock contention

                 default                         inode_lock-fix
rw=30%
Instance 1      r=54.6GiB/s,w=23.4GiB/s         r=11.4GiB/s,w=4992MiB/s
Instance 2      r=52.7GiB/s,w=22.6GiB/s         r=11.4GiB/s,w=4981MiB/s
Instance 3      r=53.3GiB/s,w=22.8GiB/s         r=12.7GiB/s,w=5575MiB/s
Instance 4      r=37.7GiB/s,w=16.2GiB/s         r=10.4GiB/s,w=4581MiB/s

Regards,
Bharata.