On Mon, May 11, 2009 at 04:54:40PM +0200, Stefan Lankes wrote: > > From: Andi Kleen [mailto:andi@xxxxxxxxxxxxxx] > > > > Stefan Lankes <lankes@xxxxxxxxxxxxxxxxxxx> writes: > > > > > > [Patch 1/4]: Extend the system call madvise with a new parameter > > > MADV_ACCESS_LWP (the same as used in Solaris). The specified memory > > area > > > > Linux does NUMA memory policies in mbind(), not madvise() > > Also if there's a new NUMA policy it should be in the standard > > Linux NUMA memory policy frame work, not inventing a new one > > By default, mbind only has an effect on new allocations. I think that this Nope, it affects existing pages too, it can even move pages if you ask for it. > is different from what we need for applications with dynamic memory access > patterns. The app gives the kernel a hint that the access pattern has been > changed and the kernel has to redistribute the pages which are already > allocated. MF_MOVE > For instance, Norden's PDE solvers using adaptive mesh refinements (AMR) [1] > is an application with a dynamic access pattern. We use this example to > evaluate the performance of our patch. We ran this solver on our > quad-socket, dual-core Opteron 875 (2.2GHz) system running CentOS 5.2. The > code was already optimized for NUMA architectures. Before the arrays are > initialized, the threads are bound to one core. In our test case, the solver > needs 5318s. If we use our kernel extension, the solver needs 4489s. Okay that sounds like good numbers. > Currently, we are testing some other apps. Please keep the list updated. -Andi -- ak@xxxxxxxxxxxxxxx -- Speaking for myself only. -- To unsubscribe from this list: send the line "unsubscribe linux-numa" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
