From 0ec20f481560cdc5edf60e7e554f51aae4c54a84 Mon Sep 17 00:00:00 2001 From: Xiaochen Shen Date: Tue, 30 Oct 2018 05:14:53 +0800 Subject: [PATCH] config-linux: documentation change for Intel RDT/MBA Software Controller support MBA Software Controller feature is introduced in Linux kernel v4.18. It is a software enhancement to mitigate some limitations in MBA which describes in kernel documentation. It also makes the interface more user friendly - we could specify memory bandwidth in "MBps" (Mega Bytes per second) as well as in "percentages". We could enable this feature through mount option "-o mba_MBps": mount -t resctrl resctrl -o mba_MBps /sys/fs/resctrl In runtime-spec, we handle both memory bandwidth schemata in unified format: "MB:=bandwidth0;=bandwidth1;..." The unit of memory bandwidth is specified in "percentages" by default, and in "MBps" if MBA Software Controller is enabled. For more information about Intel RDT and MBA Software Controller: https://www.kernel.org/doc/Documentation/x86/intel_rdt_ui.txt Signed-off-by: Xiaochen Shen --- config-linux.md | 2 +- specs-go/config.go | 4 +++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/config-linux.md b/config-linux.md index a52eb5961..bd80283e2 100644 --- a/config-linux.md +++ b/config-linux.md @@ -500,7 +500,7 @@ The following parameters can be specified for the container: * **`l3CacheSchema`** *(string, OPTIONAL)* - specifies the schema for L3 cache id and capacity bitmask (CBM). The value SHOULD start with `L3:` and SHOULD NOT contain newlines. -* **`memBwSchema`** *(string, OPTIONAL)* - specifies the schema of memory bandwidth percentage per L3 cache id. +* **`memBwSchema`** *(string, OPTIONAL)* - specifies the schema of memory bandwidth per L3 cache id. The value MUST start with `MB:` and MUST NOT contain newlines. If both `l3CacheSchema` and `memBwSchema` are set, runtimes MUST write the combined value to the `schemata` file in that sub-directory discussed in `closID`. diff --git a/specs-go/config.go b/specs-go/config.go index 9984bbce3..4591a1a00 100644 --- a/specs-go/config.go +++ b/specs-go/config.go @@ -632,7 +632,9 @@ type LinuxIntelRdt struct { // Format: "L3:=;=;..." L3CacheSchema string `json:"l3CacheSchema,omitempty"` - // The schema of memory bandwidth percentage per L3 cache id + // The schema of memory bandwidth per L3 cache id // Format: "MB:=bandwidth0;=bandwidth1;..." + // The unit of memory bandwidth is specified in "percentages" by + // default, and in "MBps" if MBA Software Controller is enabled. MemBwSchema string `json:"memBwSchema,omitempty"` }