@@ -482,6 +482,26 @@ closest to which page allocation will come from. Specifying the home node overri
the default allocation policy to allocate memory close to the local node for an
executing CPU.
+Extended Mempolicy Arguments::
+
+ struct mpol_args {
+ __u16 mode;
+ __u16 mode_flags;
+ __s32 home_node; /* mbind2: policy home node */
+ __aligned_u64 pol_nodes; /* nodemask pointer */
+ __u64 pol_maxnodes;
+ __u64 addr; /* get_mempolicy2: policy address */
+ __s32 policy_node; /* get_mempolicy2: policy node information */
+ __s32 addr_node; /* get_mempolicy2: memory range policy */
+ };
+
+The extended mempolicy argument structure is defined to allow the mempolicy
+interfaces future extensibility without the need for additional system calls.
+
+The core arguments (mode, mode_flags, pol_nodes, and pol_maxnodes) apply to
+all interfaces relative to their non-extended counterparts. Each additional
+field may only apply to specific extended interfaces. See the respective
+extended interface man page for more details.
Memory Policy Command Line Interface
====================================
@@ -27,6 +27,18 @@ enum {
MPOL_MAX, /* always last member of enum */
};
+struct mpol_args {
+ /* Basic mempolicy settings */
+ __u16 mode;
+ __u16 mode_flags;
+ __s32 home_node; /* mbind2: policy home node */
+ __aligned_u64 pol_nodes;
+ __u64 pol_maxnodes;
+ __u64 addr;
+ __s32 policy_node; /* get_mempolicy: policy node info */
+ __s32 addr_node; /* get_mempolicy: memory range policy */
+};
+
/* Flags for set_mempolicy */
#define MPOL_F_STATIC_NODES (1 << 15)
#define MPOL_F_RELATIVE_NODES (1 << 14)
This patch adds the new user-api argument structure intended for set_mempolicy2 and mbind2. struct mpol_args { __u16 mode; __u16 mode_flags; __s32 home_node; /* mbind2: policy home node */ __aligned_u64 *pol_nodes; __u64 pol_maxnodes; __u64 addr; /* get_mempolicy: policy address */ __s32 policy_node; /* get_mempolicy: policy node info */ __s32 addr_node; /* get_mempolicy: memory range policy */ }; This structure is intended to be extensible as new mempolicy extensions are added. For example, set_mempolicy_home_node was added to allow vma mempolicies to have a preferred/home node assigned. This structure allows the addition of that setting at the time the mempolicy is set, rather than requiring additional calls to modify the policy. Full breakdown of arguments as of this patch: mode: Mempolicy mode (MPOL_DEFAULT, MPOL_INTERLEAVE) mode_flags: Flags previously or'd into mode in set_mempolicy (e.g.: MPOL_F_STATIC_NODES, MPOL_F_RELATIVE_NODES) home_node: for mbind2. Allows the setting of a policy's home with the use of MPOL_MF_HOME_NODE pol_nodes: Policy nodemask pol_maxnodes: Max number of nodes in the policy nodemask policy_node: for get_mempolicy2. Returns extended information about a policy that was previously reported by passing MPOL_F_NODE to get_mempolicy. Instead of overriding the mode value, simply add a field. addr: for get_mempolicy2. Used with MPOL_F_ADDR to run get_mempolicy against the vma the address belongs to instead of the task. addr_node: for get_mempolicy2. Returns the node the address belongs to. Previously get_mempolicy() would override the output value of (mode) if MPOL_F_ADDR and MPOL_F_NODE were set. Instead, we extend mpol_args to do this by default if MPOL_F_ADDR is set and do away with MPOL_F_NODE. Suggested-by: Frank van der Linden <fvdl@google.com> Suggested-by: Vinicius Tavares Petrucci <vtavarespetr@micron.com> Suggested-by: Hasan Al Maruf <Hasan.Maruf@amd.com> Signed-off-by: Gregory Price <gregory.price@memverge.com> Co-developed-by: Vinicius Tavares Petrucci <vtavarespetr@micron.com> Signed-off-by: Vinicius Tavares Petrucci <vtavarespetr@micron.com> --- .../admin-guide/mm/numa_memory_policy.rst | 20 +++++++++++++++++++ include/uapi/linux/mempolicy.h | 12 +++++++++++ 2 files changed, 32 insertions(+)