On 11/02/2012 08:25 PM, JoonSoo Kim wrote: > Hello, Glauber. > > 2012/11/2 Glauber Costa <glommer@xxxxxxxxxxxxx>: >> On 11/02/2012 04:04 AM, Andrew Morton wrote: >>> On Thu, 1 Nov 2012 16:07:16 +0400 >>> Glauber Costa <glommer@xxxxxxxxxxxxx> wrote: >>> >>>> Hi, >>>> >>>> This work introduces the kernel memory controller for memcg. Unlike previous >>>> submissions, this includes the whole controller, comprised of slab and stack >>>> memory. >>> >>> I'm in the middle of (re)reading all this. Meanwhile I'll push it all >>> out to http://ozlabs.org/~akpm/mmots/ for the crazier testers. >>> >>> One thing: >>> >>>> Numbers can be found at https://lkml.org/lkml/2012/9/13/239 >>> >>> You claim in the above that the fork worload is 'slab intensive". Or >>> at least, you seem to - it's a bit fuzzy. >>> >>> But how slab intensive is it, really? >>> >>> What is extremely slab intensive is networking. The networking guys >>> are very sensitive to slab performance. If this hasn't already been >>> done, could you please determine what impact this has upon networking? >>> I expect Eric Dumazet, Dave Miller and Tom Herbert could suggest >>> testing approaches. >>> >> >> I can test it, but unfortunately I am unlikely to get to prepare a good >> environment before Barcelona. >> >> I know, however, that Greg Thelen was testing netperf in his setup. >> Greg, do you have any publishable numbers you could share? > > Below is my humble opinion. > I am worrying about data cache footprint which is possibly caused by > this patchset, especially slab implementation. > If there are several memcg cgroups, each cgroup has it's own kmem_caches. I answered the performance part in response to Tejun's response. Let me just add something here: Just keep in mind this is not "per memcg", this is "per memcg that are kernel-memory limited". So in a sense, you are only paying this, and allocate from different caches, if you runtime enable this. This should all be documented in the Documentation/ patch. But let me know if there is anything that needs further clarification -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>