From 6bc2cfdf82d56863b7cf5e86e37a662b2ae5d47e Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Tue, 26 Sep 2023 14:06:28 +0800 Subject: dax, kmem: calculate abstract distance with general interface Previously, a fixed abstract distance MEMTIER_DEFAULT_DAX_ADISTANCE is used for slow memory type in kmem driver. This limits the usage of kmem driver, for example, it cannot be used for HBM (high bandwidth memory). So, we use the general abstract distance calculation mechanism in kmem drivers to get more accurate abstract distance on systems with proper support. The original MEMTIER_DEFAULT_DAX_ADISTANCE is used as fallback only. Now, multiple memory types may be managed by kmem. These memory types are put into the "kmem_memory_types" list and protected by kmem_memory_type_lock. Link: https://lkml.kernel.org/r/20230926060628.265989-5-ying.huang@intel.com Signed-off-by: "Huang, Ying" Tested-by: Bharata B Rao Reviewed-by: Dave Jiang Reviewed-by: Alistair Popple Cc: Aneesh Kumar K.V Cc: Wei Xu Cc: Dan Williams Cc: Dave Hansen Cc: Davidlohr Bueso Cc: Johannes Weiner Cc: Jonathan Cameron Cc: Michal Hocko Cc: Yang Shi Cc: Rafael J Wysocki Signed-off-by: Andrew Morton --- mm/memory-tiers.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'mm/memory-tiers.c') diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c index 085321c77123..8d5291add2bc 100644 --- a/mm/memory-tiers.c +++ b/mm/memory-tiers.c @@ -586,13 +586,14 @@ EXPORT_SYMBOL_GPL(init_node_memory_type); void clear_node_memory_type(int node, struct memory_dev_type *memtype) { mutex_lock(&memory_tier_lock); - if (node_memory_types[node].memtype == memtype) + if (node_memory_types[node].memtype == memtype || !memtype) node_memory_types[node].map_count--; /* * If we umapped all the attached devices to this node, * clear the node memory type. */ if (!node_memory_types[node].map_count) { + memtype = node_memory_types[node].memtype; node_memory_types[node].memtype = NULL; put_memory_type(memtype); } -- cgit v1.2.3