Messages in this thread | | | Date | Tue, 7 Dec 2010 08:50:43 -0600 | From | "Serge E. Hallyn" <> | Subject | Re: [PATCH] user_ns: Improve the user_ns on-the-slab packaging |
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Quoting Pavel Emelyanov (xemul@parallels.com): > On 12/07/2010 05:27 PM, Serge E. Hallyn wrote: > > Quoting Pavel Emelyanov (xemul@parallels.com): > >> Currently on 64-bit arch the user_namespace is 2096 and when > >> being kmalloc-ed it resides on a 4k slab wasting 2003 bytes. > >> > >> If we allocate a separate cache for it and reduce the hash size > >> from 128 to 64 chains the packaging becomes *much* better - the > > > > Hey Pavel, > > > > I trust you've done some performance tests and found no > > regressions with a few hundred users? > > How many hundreds are you interested in? :) 128 users didn't > reveal any regressions.
I have no good guess, would have said 500, 128 sounds good :) So long as actual benchmarks showed no regression within a 95% confidence interval.
Thanks for the patch, the memory savings are impressive.
Acked-by: Serge E. Hallyn <serge@hallyn.com>
-serge
PS - I'm hoping to send out a version of the targeted capabilities (based on userns) patchset later this week.
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