Messages in this thread | | | Subject | Re: [PATCH 02/10] mm: system wide ALLOC_NO_WATERMARK | From | Peter Zijlstra <> | Date | Mon, 06 Aug 2007 20:31:02 +0200 |
| |
On Mon, 2007-08-06 at 11:21 -0700, Daniel Phillips wrote: > On Monday 06 August 2007 11:11, Christoph Lameter wrote: > > On Mon, 6 Aug 2007, Peter Zijlstra wrote: > > > Change ALLOC_NO_WATERMARK page allocation such that dipping into > > > the reserves becomes a system wide event. > > > > Shudder. That can just be a desaster for NUMA. Both performance wise > > and logic wise. One cpuset being low on memory should not affect > > applications in other cpusets.
Do note that these are only PF_MEMALLOC allocations that will break the cpuset. And one can argue that these are not application allocation but system allocations.
> Currently your system likely would have died here, so ending up with a > reserve page temporarily on the wrong node is already an improvement. > > I agree that the reserve pool should be per-node in the end, but I do > not think that serves the interest of simplifying the initial patch > set. How about a numa performance patch that adds onto the end of > Peter's series?
Trouble with keeping this per node is that all the code dealing with the reserve needs to keep per-cpu state, which given that the system is really crawling at that moment, seems excessive.
- 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/
| |