From: Anshuman Khandual khandual@linux.vnet.ibm.com
ascend inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4JMLR CVE: NA -------------------
Kernel allocation to CDM node has already been prevented by putting it's entire memory in ZONE_MOVABLE. But the CDM nodes must also be isolated from implicit allocations happening on the system.
Any isolation seeking CDM node requires isolation from implicit memory allocations from user space but at the same time there should also have an explicit way to do the memory allocation.
Platform node's both zonelists are fundamental to where the memory comes from when there is an allocation request. In order to achieve these two objectives as stated above, zonelists building process has to change as both zonelists (i.e FALLBACK and NOFALLBACK) gives access to the node's memory zones during any kind of memory allocation. The following changes are implemented in this regard.
* CDM node's zones are not part of any other node's FALLBACK zonelist * CDM node's FALLBACK list contains it's own memory zones followed by all system RAM zones in regular order as before * CDM node's zones are part of it's own NOFALLBACK zonelist
These above changes ensure the following which in turn isolates the CDM nodes as desired.
* There wont be any implicit memory allocation ending up in the CDM node * Only __GFP_THISNODE marked allocations will come from the CDM node * CDM node memory can be allocated through mbind(MPOL_BIND) interface * System RAM memory will be used as fallback option in regular order in case the CDM memory is insufficient during targted allocation request
Sample zonelist configuration:
[NODE (0)] RAM ZONELIST_FALLBACK (0xc00000000140da00) (0) (node 0) (DMA 0xc00000000140c000) (1) (node 1) (DMA 0xc000000100000000) ZONELIST_NOFALLBACK (0xc000000001411a10) (0) (node 0) (DMA 0xc00000000140c000) [NODE (1)] RAM ZONELIST_FALLBACK (0xc000000100001a00) (0) (node 1) (DMA 0xc000000100000000) (1) (node 0) (DMA 0xc00000000140c000) ZONELIST_NOFALLBACK (0xc000000100005a10) (0) (node 1) (DMA 0xc000000100000000) [NODE (2)] CDM ZONELIST_FALLBACK (0xc000000001427700) (0) (node 2) (Movable 0xc000000001427080) (1) (node 0) (DMA 0xc00000000140c000) (2) (node 1) (DMA 0xc000000100000000) ZONELIST_NOFALLBACK (0xc00000000142b710) (0) (node 2) (Movable 0xc000000001427080) [NODE (3)] CDM ZONELIST_FALLBACK (0xc000000001431400) (0) (node 3) (Movable 0xc000000001430d80) (1) (node 0) (DMA 0xc00000000140c000) (2) (node 1) (DMA 0xc000000100000000) ZONELIST_NOFALLBACK (0xc000000001435410) (0) (node 3) (Movable 0xc000000001430d80) [NODE (4)] CDM ZONELIST_FALLBACK (0xc00000000143b100) (0) (node 4) (Movable 0xc00000000143aa80) (1) (node 0) (DMA 0xc00000000140c000) (2) (node 1) (DMA 0xc000000100000000) ZONELIST_NOFALLBACK (0xc00000000143f110) (0) (node 4) (Movable 0xc00000000143aa80)
Signed-off-by: Anshuman Khandual khandual@linux.vnet.ibm.com Signed-off-by: Lijun Fang fanglijun3@huawei.com Reviewed-by: Weilong Chen chenweilong@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- mm/page_alloc.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 308b570cdcec..9bf6ce119d6d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5981,6 +5981,16 @@ static void build_zonelists(pg_data_t *pgdat)
memset(node_order, 0, sizeof(node_order)); while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { +#ifdef CONFIG_COHERENT_DEVICE + /* + * CDM node's own zones should not be part of any other + * node's fallback zonelist but only it's own fallback + * zonelist. + */ + if (is_cdm_node(node) && (pgdat->node_id != node)) + continue; +#endif + /* * We don't want to pressure a particular node. * So adding penalty to the first node in same