Re: [PATCH -V6 RESEND 2/3] NOT kernel/man-pages: man2/set_mempolicy.2: Add mode flag MPOL_F_NUMA_BALANCING
From: Mel Gorman <mgorman@suse.de>
Date: 2020-12-02 11:45:03
Also in:
linux-mm, lkml
On Wed, Dec 02, 2020 at 04:42:33PM +0800, Huang Ying wrote:
quoted hunk ↗ jump to hunk
Signed-off-by: "Huang, Ying" <redacted> --- man2/set_mempolicy.2 | 9 +++++++++ 1 file changed, 9 insertions(+)diff --git a/man2/set_mempolicy.2 b/man2/set_mempolicy.2 index 68011eecb..3754b3e12 100644 --- a/man2/set_mempolicy.2 +++ b/man2/set_mempolicy.2@@ -113,6 +113,12 @@ A nonempty .I nodemask specifies node IDs that are relative to the set of node IDs allowed by the process's current cpuset. +.TP +.BR MPOL_F_NUMA_BALANCING " (since Linux 5.11)" +Enable the Linux kernel NUMA balancing for the task if it is supported +by kernel. +If the flag isn't supported by Linux kernel, return -1 and errno is +set to EINVAL. .PP .I nodemask points to a bit mask of node IDs that contains up to@@ -293,6 +299,9 @@ argument specified both
Should this be expanded more to clarify it applies to MPOL_BIND specifically? Maybe the first patch should be expanded more and explictly fail if MPOL_F_NUMA_BALANCING is used with anything other than MPOL_BIND?
.B MPOL_F_STATIC_NODES and .BR MPOL_F_RELATIVE_NODES . +Or, the +.B MPOL_F_NUMA_BALANCING +isn't supported by the Linux kernel.
This will be difficult for an app to distinguish but we can't go back in time and make this ENOSYS :( The linux-api people might have more guidance but it may go to the extent of including a small test program in the manual page for a sequence that tests whether MPOL_F_NUMA_BALANCING works. They might have a better recommendation on how it should be handled. -- Mel Gorman SUSE Labs