Messages in this thread | | | Date | Thu, 21 Aug 2008 08:14:04 -0500 | From | Robin Holt <> | Subject | Re: [RFC][PATCH 0/2] Quicklist is slighly problematic. |
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On Thu, Aug 21, 2008 at 08:07:43AM -0500, Christoph Lameter wrote: > Robin Holt wrote: > > > > Index: ia64-cleanups/include/linux/quicklist.h > > =================================================================== > > --- ia64-cleanups.orig/include/linux/quicklist.h 2008-08-20 21:35:10.000000000 -0500 > > +++ ia64-cleanups/include/linux/quicklist.h 2008-08-20 21:38:00.891943270 -0500 > > @@ -66,6 +66,15 @@ static inline void __quicklist_free(int > > > > static inline void quicklist_free(int nr, void (*dtor)(void *), void *pp) > > { > > +#ifdef CONFIG_NUMA > > + unsigned long nid = page_to_nid(virt_to_page(pp)); > > + > > + if (unlikely(nid != numa_node_id())) { > > + free_page((unsigned long)pp); > > + return; > > + } > > +#endif > > + > > __quicklist_free(nr, dtor, pp, virt_to_page(pp)); > > } > > > > We removed this code because it frees a page before the TLB flush has been > performed. This code segment was the reason that quicklists were not accepted > for x86.
How could we do this. It was a _HUGE_ problem on altix boxes. When you started a jobs with a large number of MPI ranks, they would all start from the shepherd process on a single node and the children would migrate to a different cpu. Unless subsequent jobs used enough memory to flush those remote quicklists, we would end up with a depleted node that never reclaimed.
Thanks, Robin
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