![]() | |||||||||||||
Messages in this thread |
Paul Menage wrote: > On 10/31/06, Balbir Singh <balbir@in.ibm.com> wrote: >> I am still a little concerned about how limit size changes will be implemented. >> Will the cpuset "mems" field change to reflect the changed limits? > > That's how we've been doing it - increasing limits is easy, shrinking > them is harder ... > >>> Page cache control is actually more essential that RSS control, in our >>> experience - it's pretty easy to track RSS values from userspace, and >>> react reasonably quickly to kill things that go over their limit, but >>> determining page cache usage (i.e. determining which job on the system >>> is flooding the page cache with dirty buffers) is pretty much >>> impossible currently. >>> >> Hmm... interesting. Why do you think its impossible, what are the kinds of >> issues you've run into? >> > > Issues such as: > > - determining from userspace how much of the page cache is really > "free" memory that can be given out to new jobs without impacting the > performance of existing jobs > > - determining which job on the system is flooding the page cache with > dirty buffers > > - accounting the active pagecache usage of a job as part of its memory > footprint (if a process is only 1MB large but is seeking randomly > through a 1GB file, treating it as only using/needing 1MB isn't > practical). > > Paul > Thanks for the info! I thought this would be hard to do in general, but with a page --> container mapping that will come as a result of the memory controller, will it still be that hard? I'll dig deeper. -- Balbir Singh, Linux Technology Center, IBM Software Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
| Last update: 2006-11-01 08:09 [from the cache] ©2003-2008 | |||||||||||||