Improving OOTB performance

Eero Tamminen oak at helsinkinet.fi
Sat May 19 00:23:08 UTC 2012


Hi,

On lauantai 19 toukokuu 2012, Сергей Давыдов wrote:
> Thanks for testing out my proposals!

Well, I didn't really test them, they've been fairly
extensively analyzed in MeeGo/Harmattan during last couple
of years. :-)

(Also, one of the kernel memory cgroups developers worked
for Nokia and pushed some cgroups features upstream.)


> Ulatency supports per-cgroup swappiness control, so it can set
> swappiness to zero for media apps
> (given the following kernel parameters:
> CONFIG_CGROUP_MEM_RES_CTLR_SWAP=y
> CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED=y )
> 
> Everything else can be zramswapped out of the way of media apps
> (ubuntu has swappiness 60 by default so it *will* be zramswapped out
> of the way).
> 
> Alternatively, it should be fairly easy to write an LD_PRELOAD
> override for malloc() that also applies memlock() to that region, but
> I'm afraid it can slow down malloc() calls so controlling swap with
> ulatencyd is preferable.

LD_PRELOAD (and LD_AUDIT) are more of debugging facilities
and doing mlock for individual mallocs doesn't sound practical.

Better idea than trying to use mlock() in malloc is e.g. using
this:
	http://maemo.gitorious.org/maemo-tools/libmlocknice

To do targeted mlocking of specific memory process memory
mappings (e.g. process heap).


	- Eero



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