Messages in this thread | | | Date | Tue, 20 Dec 2011 17:14:18 -0800 | From | Frank Rowand <> | Subject | Re: Android low memory killer vs. memory pressure notifications |
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On 12/20/11 16:28, Anton Vorontsov wrote: > On Tue, Dec 20, 2011 at 01:36:00PM -0800, David Rientjes wrote: >> On Tue, 20 Dec 2011, Anton Vorontsov wrote: >> >>> Hm, assuming that metadata is no longer an issue, why do you think avoiding >>> cgroups would be a good idea? >>> >> >> It's helpful for certain end users, particularly those in the embedded >> world, to be able to disable as many config options as possible to reduce >> the size of kernel image as much as possible, so they'll want a minimal >> amount of kernel functionality that allows such notifications. Keep in >> mind that CONFIG_CGROUP_MEM_RES_CTLR is not enabled by default because of >> this (enabling it, CONFIG_RESOURCE_COUNTERS, and CONFIG_CGROUPS increases >> the size of the kernel text by ~1%), > > So for 2MB kernel that's about 20KB of an additional text... This seems > affordable, especially as a trade-off for the things that cgroups may > provide.
A comment from http://lkml.indiana.edu/hypermail/linux/kernel/1102.1/00412.html:
"I care about 5K. (But honestly, I don't actively hunt stuff less than 10K in size, because there's too many of them to chase, currently)."
> > The fact is, for desktop and server Linux, cgroups slowly becomes a > mandatory thing. And the reason for this is that cgroups mechanism > provides some very useful features (in an extensible way, like plugins), > i.e. a way to manage and track processes and its resources -- which is the > main purpose of cgroups.
And for embedded and for real-time, some of us do not want cgroups to be a mandatory thing. We want it to remain configurable. My personal interest is in keeping the latency of certain critical paths (especially in the scheduler) short and consistent.
-Frank
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