Hi Mark!
On 01/25/2016 08:00 PM, Mark Seger wrote:
> hey bernd, long time no chat. it turns out you don't have to know what
> swift is because I've been able to demonstrate this behavior with a very
> simple python script that simply creates files in a 3-tier hierarchy. the
> third level directories each contain a single file which for my testing are
> all 1K.
So what is the script exactly doing? Does it create those files
sequentially per dir or randomly between those dirs?
Btw, I had been talking about that issue at linux plumbers in 2013
https://www.youtube.com/watch?v=N_bZOGZAb-Y
>
> I have played wiht cache_pressure and it doesn't seem to make a difference,
> though that was awhlle ago and perhaps it is worth revisiting. one thing
There are several patches from Mel Gorman in 3.11, which really made a
difference for me. So unless you tested with >= 3.11 you should probably
re-test.
> you may get a hoot out of, being a collectl user, is I have an xfs plugin
> that lets you look at a ton of xfs stats either in realtime or after the
> fact just like any other collectl stat. I just havent' added it to the kit
> yet.
Hmm, I currently don't have good a test system for that. I'm working on
an entirely different project now and while this is also a parallel file
system, it does not have a linux file system in between, but has its own
(log rotated) layout.
Cheers,
Bernd
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