On 09/29/2015 12:59 AM, Dałek, Piotr wrote:
-----Original Message-----
From: ceph-devel-owner@xxxxxxxxxxxxxxx [mailto:ceph-devel-
owner@xxxxxxxxxxxxxxx] On Behalf Of Mark Nelson
Sent: Tuesday, September 29, 2015 1:34 AM
Hi Everyone,
A while back Alexandre Derumier posted some test results looking at how
transparent huge pages can reduce memory usage with jemalloc. I went
back and ran a number of new tests on the community performance cluster
to verify his findings and also look at how performance and cpu usage were
affected, both during various fio benchmark tests and also during a 4k
random write recovery scenario. I tested tcmalloc 2.4 with 32MB thread
cache, 128MB thread cache, and jemalloc 4.0.
[..]
Here's are the results:
https://drive.google.com/file/d/0B2gTBZrkrnpZY3U3TUU3RkJVeVk/view
From my point of view, this looks excellent. I generally didn't like the idea of moving to Jemalloc because of memory usage increase (which is absurdly high as you can see from the graphs), but with THP disabled things look way better.
How about trying Jemalloc 4 without THP and with Ceph patched with https://github.com/ceph/ceph/pull/5855? I wonder how much difference it'll give on Incerta.
I actually did try 5855, but there was a nasty monitor memory leak in
master that prevented the tests from running. It didn't get fixed until
early last week and 5855 no longer merges cleanly with latest master. I
haven't had time to go back and see what's conflicting, but if you want
to take a look and update it I would be happy to give it a whirl. :)
Mark
With best regards / Pozdrawiam
Piotr Dałek
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