From: "Ho-Ren (Jack) Chuang" <horenchuang@bytedance.com> mainline inclusion from mainline-v6.10-rc1 commit a72a30af550c08423de1b9feecb6ceeddc434889 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9812 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------- Patch series "Improved Memory Tier Creation for CPUless NUMA Nodes", v11. When a memory device, such as CXL1.1 type3 memory, is emulated as normal memory (E820_TYPE_RAM), the memory device is indistinguishable from normal DRAM in terms of memory tiering with the current implementation. The current memory tiering assigns all detected normal memory nodes to the same DRAM tier. This results in normal memory devices with different attributions being unable to be assigned to the correct memory tier, leading to the inability to migrate pages between different types of memory. https://lore.kernel.org/linux-mm/PH0PR08MB7955E9F08CCB64F23963B5C3A860A@PH0P... This patchset automatically resolves the issues. It delays the initialization of memory tiers for CPUless NUMA nodes until they obtain HMAT information and after all devices are initialized at boot time, eliminating the need for user intervention. If no HMAT is specified, it falls back to using `default_dram_type`. Example usecase: We have CXL memory on the host, and we create VMs with a new system memory device backed by host CXL memory. We inject CXL memory performance attributes through QEMU, and the guest now sees memory nodes with performance attributes in HMAT. With this change, we enable the guest kernel to construct the correct memory tiering for the memory nodes. This patch (of 2): Since different memory devices require finding, allocating, and putting memory types, these common steps are abstracted in this patch, enhancing the scalability and conciseness of the code. Link: https://lkml.kernel.org/r/20240405000707.2670063-1-horenchuang@bytedance.com Link: https://lkml.kernel.org/r/20240405000707.2670063-2-horenchuang@bytedance.com Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawie.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gregory Price <gourry.memverge@gmail.com> Cc: Hao Xiang <hao.xiang@bytedance.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Ravi Jonnalagadda <ravis.opensrc@micron.com> Cc: SeongJae Park <sj@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> --- drivers/dax/kmem.c | 30 ++++-------------------------- include/linux/memory-tiers.h | 13 +++++++++++++ mm/memory-tiers.c | 29 +++++++++++++++++++++++++++++ 3 files changed, 46 insertions(+), 26 deletions(-) diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index 2fb74acc0703..ca0f482ea7cb 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -54,36 +54,14 @@ static LIST_HEAD(kmem_memory_types); static struct memory_dev_type *kmem_find_alloc_memory_type(int adist) { - bool found = false; - struct memory_dev_type *mtype; - - mutex_lock(&kmem_memory_type_lock); - list_for_each_entry(mtype, &kmem_memory_types, list) { - if (mtype->adistance == adist) { - found = true; - break; - } - } - if (!found) { - mtype = alloc_memory_type(adist); - if (!IS_ERR(mtype)) - list_add(&mtype->list, &kmem_memory_types); - } - mutex_unlock(&kmem_memory_type_lock); - - return mtype; + guard(mutex)(&kmem_memory_type_lock); + return mt_find_alloc_memory_type(adist, &kmem_memory_types); } static void kmem_put_memory_types(void) { - struct memory_dev_type *mtype, *mtn; - - mutex_lock(&kmem_memory_type_lock); - list_for_each_entry_safe(mtype, mtn, &kmem_memory_types, list) { - list_del(&mtype->list); - put_memory_type(mtype); - } - mutex_unlock(&kmem_memory_type_lock); + guard(mutex)(&kmem_memory_type_lock); + mt_put_memory_types(&kmem_memory_types); } static int dev_dax_kmem_probe(struct dev_dax *dev_dax) diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h index 6debda505b51..f0bbd272f152 100644 --- a/include/linux/memory-tiers.h +++ b/include/linux/memory-tiers.h @@ -48,6 +48,9 @@ int mt_calc_adistance(int node, int *adist); int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, const char *source); int mt_perf_to_adistance(struct access_coordinate *perf, int *adist); +struct memory_dev_type *mt_find_alloc_memory_type(int adist, + struct list_head *memory_types); +void mt_put_memory_types(struct list_head *memory_types); #ifdef CONFIG_MIGRATION int next_demotion_node(int node); void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets); @@ -136,5 +139,15 @@ static inline int mt_perf_to_adistance(struct access_coordinate *perf, int *adis { return -EIO; } + +static inline struct memory_dev_type *mt_find_alloc_memory_type(int adist, + struct list_head *memory_types) +{ + return NULL; +} + +static inline void mt_put_memory_types(struct list_head *memory_types) +{ +} #endif /* CONFIG_NUMA */ #endif /* _LINUX_MEMORY_TIERS_H */ diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c index 393f91e665f3..b3bfc93b529c 100644 --- a/mm/memory-tiers.c +++ b/mm/memory-tiers.c @@ -642,6 +642,35 @@ void clear_node_memory_type(int node, struct memory_dev_type *memtype) } EXPORT_SYMBOL_GPL(clear_node_memory_type); +struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types) +{ + struct memory_dev_type *mtype; + + list_for_each_entry(mtype, memory_types, list) + if (mtype->adistance == adist) + return mtype; + + mtype = alloc_memory_type(adist); + if (IS_ERR(mtype)) + return mtype; + + list_add(&mtype->list, memory_types); + + return mtype; +} +EXPORT_SYMBOL_GPL(mt_find_alloc_memory_type); + +void mt_put_memory_types(struct list_head *memory_types) +{ + struct memory_dev_type *mtype, *mtn; + + list_for_each_entry_safe(mtype, mtn, memory_types, list) { + list_del(&mtype->list); + put_memory_type(mtype); + } +} +EXPORT_SYMBOL_GPL(mt_put_memory_types); + static void dump_hmem_attrs(struct access_coordinate *coord, const char *prefix) { pr_info( -- 2.43.0