On Mon, Feb 21, 2005 at 02:42:16AM -0600, Ray Bryant wrote: > All, > > Just an update on the idea of migrating a process without suspending > it. > > The hard part of the problem here is to make sure that the page_migrate() > system call sees all of the pages to migrate. If the process that is > being migrated can still allocate pages, then the page_migrate() call > may miss some of the pages.
I would do an easy 95% solution: When process has default process policy set temporarily a prefered policy with the new node [this won't work with multiple nodes though, so you have to decide on one or stop the process if that is unacceptable] > > One way to solve this problem is to force the process to start allocating > pages on the new nodes before calling page_migrate(). There are a couple > of subcases: > > (1) For memory mapped files with a non-DEFAULT associated memory policy, > one can use mbind() to fixup the memory policy. (This assumes the > Steve Longerbeam patches are applied, as I understand things). I would just ignore them. If user space wants it can handle it, but it's probably not worth it. > (1) could be handled as part of the page_migrate() system call -- > make one pass through the address space searching for mempolicy() > data structures, and updating them as necessary. Then make a second > pass through and do the migrations. Any new allocations will then > be done under the new mempolicy, so they won't be missed. But this > still gets us into trouble if the old and new node lists are not > disjoint. I wouldn't bother fixing up VMA policies. > This doesn't handle anonymous memory or mapped files associated with > the DEFAULT policy. A way around that would be to add a target cpu_id [...] I would set temporarily a prefered policy as mentioned above. That only handles a single node, but you solution is not better. -Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
