From 92bf7eb59fd382914a92dcb8f4dacbb059f63cbc Mon Sep 17 00:00:00 2001 From: Svetly Todorov Date: Tue, 23 Apr 2024 16:36:56 -0700 Subject: man2/: Add MPOL_WEIGHTED_INTERLEAVE documentation Add documentation for the new MPOL_WEIGHTED_INTERLEAVE mode in the same manual pages that mention MPOL_INTERLEAVE; namely, mbind(2), set_mempolicy(2), and get_mempolicy(2). Descriptions were based on the changes introduced in this patch: Which was upstreamed to 6.9 here: Cc: gregory.price@memverge.com Reviewed-by: "Huang, Ying" Signed-off-by: Svetly Todorov Signed-off-by: Alejandro Colomar --- man2/get_mempolicy.2 | 10 +++++++--- man2/mbind.2 | 18 ++++++++++++++++++ man2/set_mempolicy.2 | 18 ++++++++++++++++++ 3 files changed, 43 insertions(+), 3 deletions(-) diff --git a/man2/get_mempolicy.2 b/man2/get_mempolicy.2 index 5248f04ba..f6f80ab3e 100644 --- a/man2/get_mempolicy.2 +++ b/man2/get_mempolicy.2 @@ -137,7 +137,9 @@ specifies but not .BR MPOL_F_ADDR , and the thread's current policy is -.BR MPOL_INTERLEAVE , +.B MPOL_INTERLEAVE +or +.BR MPOL_WEIGHTED_INTERLEAVE , then .BR get_mempolicy () will return in the location pointed to by a non-NULL @@ -205,8 +207,10 @@ specified .B MPOL_F_NODE but not .B MPOL_F_ADDR -and the current thread policy is not -.BR MPOL_INTERLEAVE . +and the current thread policy is neither +.B MPOL_INTERLEAVE +nor +.BR MPOL_WEIGHTED_INTERLEAVE . Or, .I flags specified diff --git a/man2/mbind.2 b/man2/mbind.2 index b0e961f9c..96264ce81 100644 --- a/man2/mbind.2 +++ b/man2/mbind.2 @@ -105,6 +105,7 @@ argument must specify one of .BR MPOL_DEFAULT , .BR MPOL_BIND , .BR MPOL_INTERLEAVE , +.BR MPOL_WEIGHTED_INTERLEAVE , .BR MPOL_PREFERRED , or .B MPOL_LOCAL @@ -243,6 +244,23 @@ at least 1\ MB or bigger with a fairly uniform access pattern. Accesses to a single page of the area will still be limited to the memory bandwidth of a single node. .TP +.BR MPOL_WEIGHTED_INTERLEAVE " (since Linux 6.9)" +.\" commit fa3bea4e1f8202d787709b7e3654eb0a99aed758 +This mode interleaves page allocations across the nodes specified in +.I nodemask +according to the weights in +.IR /sys/kernel/mm/mempolicy/weighted_interleave . +For example, if bits 0, 2, and 5 are set in +.IR nodemask , +and the contents of +.IR /sys/kernel/mm/mempolicy/weighted_interleave/node0 , +.IR /sys/ .\|.\|. /node2 , +and +.IR /sys/ .\|.\|. /node5 +are 4, 7, and 9, respectively, +then pages in this region will be allocated on nodes 0, 2, and 5 +in a 4:7:9 ratio. +.TP .B MPOL_PREFERRED This mode sets the preferred node for allocation. The kernel will try to allocate pages from this diff --git a/man2/set_mempolicy.2 b/man2/set_mempolicy.2 index fc3ad9df8..f1f225e32 100644 --- a/man2/set_mempolicy.2 +++ b/man2/set_mempolicy.2 @@ -63,6 +63,7 @@ argument must specify one of .BR MPOL_DEFAULT , .BR MPOL_BIND , .BR MPOL_INTERLEAVE , +.BR MPOL_WEIGHTED_INTERLEAVE , .BR MPOL_PREFERRED , or .B MPOL_LOCAL @@ -199,6 +200,23 @@ the memory bandwidth of a single node. .\" To be effective the memory area should be fairly large, .\" at least 1 MB or bigger. .TP +.BR MPOL_WEIGHTED_INTERLEAVE " (since Linux 6.9)" +.\" commit fa3bea4e1f8202d787709b7e3654eb0a99aed758 +This mode interleaves page allocations across the nodes specified in +.I nodemask +according to the weights in +.IR /sys/kernel/mm/mempolicy/weighted_interleave . +For example, if bits 0, 2, and 5 are set in +.IR nodemask , +and the contents of +.IR /sys/kernel/mm/mempolicy/weighted_interleave/node0 , +.IR /sys/ .\|.\|. /node2 , +and +.IR /sys/ .\|.\|. /node5 +are 4, 7, and 9, respectively, +then pages in this region will be allocated on nodes 0, 2, and 5 +in a 4:7:9 ratio. +.TP .B MPOL_PREFERRED This mode sets the preferred node for allocation. The kernel will try to allocate pages from this node first -- cgit v1.2.3