| Message ID | 20231122141559.4228-2-laoar.shao@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm, security, bpf: Fine-grained control over memory policy adjustments with lsm bpf | expand |
Yafang Shao <laoar.shao@gmail.com> writes: > The document on MPOL_F_NUMA_BALANCING was missed in the initial commit > The MPOL_F_NUMA_BALANCING document was inadvertently omitted from the > initial commit bda420b98505 ("numa balancing: migrate on fault among > multiple bound nodes") > > Let's ensure its inclusion. > > Signed-off-by: Yafang Shao <laoar.shao@gmail.com> > Cc: "Huang, Ying" <ying.huang@intel.com> LGTM, Thanks! Reviewed-by: "Huang, Ying" <ying.huang@intel.com> > --- > .../admin-guide/mm/numa_memory_policy.rst | 27 +++++++++++++++++++ > 1 file changed, 27 insertions(+) > > diff --git a/Documentation/admin-guide/mm/numa_memory_policy.rst b/Documentation/admin-guide/mm/numa_memory_policy.rst > index eca38fa81e0f..19071b71979c 100644 > --- a/Documentation/admin-guide/mm/numa_memory_policy.rst > +++ b/Documentation/admin-guide/mm/numa_memory_policy.rst > @@ -332,6 +332,33 @@ MPOL_F_RELATIVE_NODES > MPOL_PREFERRED policies that were created with an empty nodemask > (local allocation). > > +MPOL_F_NUMA_BALANCING (since Linux 5.12) > + When operating in MPOL_BIND mode, enables NUMA balancing for tasks, > + contingent upon kernel support. This feature optimizes page > + placement within the confines of the specified memory binding > + policy. The addition of the MPOL_F_NUMA_BALANCING flag augments the > + control mechanism for NUMA balancing: > + > + - The sysctl knob numa_balancing governs global activation or > + deactivation of NUMA balancing. > + > + - Even if sysctl numa_balancing is enabled, NUMA balancing remains > + disabled by default for memory areas or applications utilizing > + explicit memory policies. > + > + - The MPOL_F_NUMA_BALANCING flag facilitates NUMA balancing > + activation for applications employing explicit memory policies > + (MPOL_BIND). > + > + This flags enables various optimizations for page placement through > + NUMA balancing. For instance, when an application's memory is bound > + to multiple nodes (MPOL_BIND), the hint page fault handler attempts > + to migrate accessed pages to reduce cross-node access if the > + accessing node aligns with the policy nodemask. > + > + If the flag isn't supported by the kernel, or is used with mode > + other than MPOL_BIND, -1 is returned and errno is set to EINVAL. > + > Memory Policy Reference Counting > ================================ -- Best Regards, Huang, Ying
diff --git a/Documentation/admin-guide/mm/numa_memory_policy.rst b/Documentation/admin-guide/mm/numa_memory_policy.rst index eca38fa81e0f..19071b71979c 100644 --- a/Documentation/admin-guide/mm/numa_memory_policy.rst +++ b/Documentation/admin-guide/mm/numa_memory_policy.rst @@ -332,6 +332,33 @@ MPOL_F_RELATIVE_NODES MPOL_PREFERRED policies that were created with an empty nodemask (local allocation). +MPOL_F_NUMA_BALANCING (since Linux 5.12) + When operating in MPOL_BIND mode, enables NUMA balancing for tasks, + contingent upon kernel support. This feature optimizes page + placement within the confines of the specified memory binding + policy. The addition of the MPOL_F_NUMA_BALANCING flag augments the + control mechanism for NUMA balancing: + + - The sysctl knob numa_balancing governs global activation or + deactivation of NUMA balancing. + + - Even if sysctl numa_balancing is enabled, NUMA balancing remains + disabled by default for memory areas or applications utilizing + explicit memory policies. + + - The MPOL_F_NUMA_BALANCING flag facilitates NUMA balancing + activation for applications employing explicit memory policies + (MPOL_BIND). + + This flags enables various optimizations for page placement through + NUMA balancing. For instance, when an application's memory is bound + to multiple nodes (MPOL_BIND), the hint page fault handler attempts + to migrate accessed pages to reduce cross-node access if the + accessing node aligns with the policy nodemask. + + If the flag isn't supported by the kernel, or is used with mode + other than MPOL_BIND, -1 is returned and errno is set to EINVAL. + Memory Policy Reference Counting ================================
The document on MPOL_F_NUMA_BALANCING was missed in the initial commit The MPOL_F_NUMA_BALANCING document was inadvertently omitted from the initial commit bda420b98505 ("numa balancing: migrate on fault among multiple bound nodes") Let's ensure its inclusion. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Cc: "Huang, Ying" <ying.huang@intel.com> --- .../admin-guide/mm/numa_memory_policy.rst | 27 +++++++++++++++++++ 1 file changed, 27 insertions(+)