Hi Andi, On Tue, Jul 26, 2011 at 5:37 AM, Andi Kleen <ak@xxxxxxxxxxxxxxx> wrote: >> The global dirty limits are put in proportion to the respective zone's >> amount of dirtyable memory and the allocation denied when the limit of >> that zone is reached. >> >> Before the allocation fails, the allocator slowpath has a stage before >> compaction and reclaim, where the flusher threads are kicked and the >> allocator ultimately has to wait for writeback if still none of the >> zones has become eligible for allocation again in the meantime. >> > > I don't really like this. It seems wrong to make memory > placement depend on dirtyness. > > Just try to explain it to some system administrator or tuner: her > head will explode and for good reasons. > > On the other hand I like doing round-robin in filemap by default > (I think that is what your patch essentially does) > We should have made this default long ago. It avoids most of the > "IO fills up local node" problems people run into all the time. > > So I would rather just change the default in filemap allocation. > > That's also easy to explain. Just out of curiosity. Why do you want to consider only filemap allocation, not IO(ie, filemap + sys_[read/write]) allocation? -- Kind regards, Minchan Kim -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href