Hi,
On 1/3/24 14:42, Gregory Price wrote:
> This patch adds the new user-api argument structure intended for
> set_mempolicy2 and mbind2.
>
> struct mpol_param {
> __u16 mode;
> __u16 mode_flags;
> __s32 home_node; /* mbind2: policy home node */
> __u16 pol_maxnodes;
> __u8 resv[6];
> __aligned_u64 *pol_nodes;
> };
>
> 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 user
> to set the home node at the time mempolicy is created, rather than
> requiring an additional syscalls.
>
> 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_maxnodes: Max number of nodes in the policy nodemask
>
> pol_nodes: Policy nodemask
>
> The reserved field accounts explicitly for a potential memory hole
> in the structure.
>
> Suggested-by: Frank van der Linden <fvdl@xxxxxxxxxx>
> Suggested-by: Vinicius Tavares Petrucci <vtavarespetr@xxxxxxxxxx>
> Suggested-by: Hasan Al Maruf <Hasan.Maruf@xxxxxxx>
> Signed-off-by: Gregory Price <gregory.price@xxxxxxxxxxxx>
> Co-developed-by: Vinicius Tavares Petrucci <vtavarespetr@xxxxxxxxxx>
> Signed-off-by: Vinicius Tavares Petrucci <vtavarespetr@xxxxxxxxxx>
> ---
> .../admin-guide/mm/numa_memory_policy.rst | 17 +++++++++++++++++
> include/linux/syscalls.h | 1 +
> include/uapi/linux/mempolicy.h | 9 +++++++++
> 3 files changed, 27 insertions(+)
>
> diff --git a/Documentation/admin-guide/mm/numa_memory_policy.rst b/Documentation/admin-guide/mm/numa_memory_policy.rst
> index a70f20ce1ffb..cbfc5f65ed77 100644
> --- a/Documentation/admin-guide/mm/numa_memory_policy.rst
> +++ b/Documentation/admin-guide/mm/numa_memory_policy.rst
> @@ -480,6 +480,23 @@ 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_param {
> + __u16 mode;
> + __u16 mode_flags;
> + __s32 home_node; /* mbind2: set home node */
> + __u64 pol_maxnodes;
> + __aligned_u64 pol_nodes; /* nodemask pointer */
> + };
>
Can you make the above documentation struct agree with the
struct in the header below, please?
(just a difference in the size of pol_maxnodes and the
'resv' bytes)
> +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
> ====================================
> diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h
> index 1f9bb10d1a47..109788c8be92 100644
> --- a/include/uapi/linux/mempolicy.h
> +++ b/include/uapi/linux/mempolicy.h
> @@ -27,6 +27,15 @@ enum {
> MPOL_MAX, /* always last member of enum */
> };
>
> +struct mpol_param {
> + __u16 mode;
> + __u16 mode_flags;
> + __s32 home_node; /* mbind2: policy home node */
> + __u16 pol_maxnodes;
> + __u8 resv[6];
> + __aligned_u64 pol_nodes;
> +};
> +
> /* Flags for set_mempolicy */
> #define MPOL_F_STATIC_NODES (1 << 15)
> #define MPOL_F_RELATIVE_NODES (1 << 14)
--
#Randy
