[Linux-cachefs] Reset /proc/fs/fscache/stats

[David Howells]

"Edward \"Koko\" Konetzko" <konetzed at quixoticagony.com> wrote:

> Is there a way to reset the counters in "/proc/fs/fscache/stats", w/o having
> to reboot the server? I know there was no way of doing this before but I didnt
> know if the new patches added that feature or not.

No.  A rough version can be added fairly easily, though (provided you don't
mind the stats being incremented as they're being cleared).  One of the
reasons I didn't just throw one together is that I was pondering changing the
way stats are handled.

Currently, I have just one counter per CPU, but that's bad for performance,
since the counters are liable to end up ping-ponging around the cachelines.

What I'm thinking of is moving to the NFS model, where you have a separate
bank of counters per CPU.  Most of the time they're just incremented, not
read, so this would be better in the former case.  Displaying the counters is
a little more tricky.

David