Messages in this thread | | | Subject | Re: [PATCH 02/10] mm/numa: automatically generate node migration order | From | David Hildenbrand <> | Date | Wed, 14 Apr 2021 10:12:29 +0200 |
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On 14.04.21 10:08, Oscar Salvador wrote: > On Fri, Apr 09, 2021 at 08:07:08PM -0700, Wei Xu wrote: >> On Thu, Apr 1, 2021 at 11:35 AM Dave Hansen <dave.hansen@linux.intel.com> wrote: >>> + * When Node 0 fills up, its memory should be migrated to >>> + * Node 1. When Node 1 fills up, it should be migrated to >>> + * Node 2. The migration path start on the nodes with the >>> + * processors (since allocations default to this node) and >>> + * fast memory, progress through medium and end with the >>> + * slow memory: >>> + * >>> + * 0 -> 1 -> 2 -> stop >>> + * 3 -> 4 -> 5 -> stop >>> + * >>> + * This is represented in the node_demotion[] like this: >>> + * >>> + * { 1, // Node 0 migrates to 1 >>> + * 2, // Node 1 migrates to 2 >>> + * -1, // Node 2 does not migrate >>> + * 4, // Node 3 migrates to 4 >>> + * 5, // Node 4 migrates to 5 >>> + * -1} // Node 5 does not migrate >>> + */ >> >> In this example, if we want to support multiple nodes as the demotion >> target of a source node, we can group these nodes into three tiers >> (classes): >> >> fast class: >> 0 -> {1, 4} // 1 is the preferred >> 3 -> {4, 1} // 4 is the preferred >> >> medium class: >> 1 -> {2, 5} // 2 is the preferred >> 4 -> {5, 2} // 5 is the preferred >> >> slow class: >> 2 -> stop >> 5 -> stop > > Hi Wei Xu, > > I have some questions about it > > Fast class/memory are pictured as those nodes with CPUs, while Slow class/memory > are PMEM, right? > Then, what stands for medium class/memory?
My guest best is that fast class is something like HBM (High Bandwidth Memory), medium class is ordinary RAM, slow class is PMEM.
-- Thanks,
David / dhildenb
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