The MPOL_LOCAL mode has been implemented by Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> (commit: 479e2802d09f1e18a97262c4c6f8f17ae5884bd8). Add the documentation for this mode. Signed-off-by: Piotr Kwapulinski <kwapulinski.piotr@xxxxxxxxx> --- This version adds more details about MPOL_LOCAL mode: 1. difference between MPOL_LOCAL and MPOL_DEFAULT 2. what if local node is overallocated or not allowed by the cpuset --- man2/mbind.2 | 28 ++++++++++++++++++++++++---- man2/set_mempolicy.2 | 19 ++++++++++++++++++- 2 files changed, 42 insertions(+), 5 deletions(-) diff --git a/man2/mbind.2 b/man2/mbind.2 index 3ea24f6..1dbda1e 100644 --- a/man2/mbind.2 +++ b/man2/mbind.2 @@ -130,8 +130,9 @@ argument must specify one of .BR MPOL_DEFAULT , .BR MPOL_BIND , .BR MPOL_INTERLEAVE , +.BR MPOL_PREFERRED , or -.BR MPOL_PREFERRED . +.BR MPOL_LOCAL . All policy modes except .B MPOL_DEFAULT require the caller to specify via the @@ -258,9 +259,26 @@ and .I maxnode arguments specify the empty set, then the memory is allocated on the node of the CPU that triggered the allocation. -This is the only way to specify "local allocation" for a -range of memory via -.BR mbind (). + +.B MPOL_LOCAL +specifies the "local allocation", the memory is allocated on +the node of the CPU that triggered the allocation, "local node". +The +.I nodemask +and +.I maxnode +arguments must specify the empty set. If the "local node" is low +on free memory the kernel will try to allocate memory from other +nodes. The kernel will allocate memory from the "local node" +whenever the memory for this node will be released. If the +"local node" is not allowed by the process's current cpuset context +the kernel will try to allocate memory from other nodes. The kernel +will allocate memory from the "local node" whenever it becomes +allowed by the process's current cpuset context. In contrast +.B MPOL_DEFAULT +reverts to the policy of the process which may have been set with +.BR set_mempolicy (2). +It may not be the "local allocation". If .B MPOL_MF_STRICT @@ -440,6 +458,8 @@ To select explicit "local allocation" for a memory range, specify a .I mode of +.B MPOL_LOCAL +or .B MPOL_PREFERRED with an empty set of nodes. This method will work for diff --git a/man2/set_mempolicy.2 b/man2/set_mempolicy.2 index 1f02037..3592734 100644 --- a/man2/set_mempolicy.2 +++ b/man2/set_mempolicy.2 @@ -79,8 +79,9 @@ argument must specify one of .BR MPOL_DEFAULT , .BR MPOL_BIND , .BR MPOL_INTERLEAVE , +.BR MPOL_PREFERRED , or -.BR MPOL_PREFERRED . +.BR MPOL_LOCAL . All modes except .B MPOL_DEFAULT require the caller to specify via the @@ -211,6 +212,22 @@ arguments specify the empty set, then the policy specifies "local allocation" (like the system default policy discussed above). +.B MPOL_LOCAL +specifies the "local allocation", the memory is allocated on +the node of the CPU that triggered the allocation, "local node". +The +.I nodemask +and +.I maxnode +arguments must specify the empty set. If the "local node" is low +on free memory the kernel will try to allocate memory from other +nodes. The kernel will allocate memory from the "local node" +whenever the memory for this node will be released. If the +"local node" is not allowed by the process's current cpuset context +the kernel will try to allocate memory from other nodes. The kernel +will allocate memory from the "local node" whenever it becomes +allowed by the process's current cpuset context. + The thread memory policy is preserved across an .BR execve (2), and is inherited by child threads created using -- 2.10.0 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
