diff options
| -rw-r--r-- | Documentation/x86/x86_64/fake-numa-for-cpusets.rst (renamed from Documentation/x86/x86_64/fake-numa-for-cpusets) | 25 | ||||
| -rw-r--r-- | Documentation/x86/x86_64/index.rst | 1 |
2 files changed, 19 insertions, 7 deletions
diff --git a/Documentation/x86/x86_64/fake-numa-for-cpusets b/Documentation/x86/x86_64/fake-numa-for-cpusets.rst index 4b09f18831f8..74fbb78b3c67 100644 --- a/Documentation/x86/x86_64/fake-numa-for-cpusets +++ b/Documentation/x86/x86_64/fake-numa-for-cpusets.rst @@ -1,5 +1,12 @@ +.. SPDX-License-Identifier: GPL-2.0 + +===================== +Fake NUMA For CPUSets +===================== + +:Author: David Rientjes <rientjes@cs.washington.edu> + Using numa=fake and CPUSets for Resource Management -Written by David Rientjes <rientjes@cs.washington.edu> This document describes how the numa=fake x86_64 command-line option can be used in conjunction with cpusets for coarse memory management. Using this feature, @@ -20,7 +27,7 @@ you become more familiar with using this combination for resource control, you'll determine a better setup to minimize the number of nodes you have to deal with. -A machine may be split as follows with "numa=fake=4*512," as reported by dmesg: +A machine may be split as follows with "numa=fake=4*512," as reported by dmesg:: Faking node 0 at 0000000000000000-0000000020000000 (512MB) Faking node 1 at 0000000020000000-0000000040000000 (512MB) @@ -34,7 +41,7 @@ A machine may be split as follows with "numa=fake=4*512," as reported by dmesg: Now following the instructions for mounting the cpusets filesystem from Documentation/cgroup-v1/cpusets.txt, you can assign fake nodes (i.e. contiguous memory -address spaces) to individual cpusets: +address spaces) to individual cpusets:: [root@xroads /]# mkdir exampleset [root@xroads /]# mount -t cpuset none exampleset @@ -47,7 +54,7 @@ Now this cpuset, 'ddset', will only allowed access to fake nodes 0 and 1 for memory allocations (1G). You can now assign tasks to these cpusets to limit the memory resources -available to them according to the fake nodes assigned as mems: +available to them according to the fake nodes assigned as mems:: [root@xroads /exampleset/ddset]# echo $$ > tasks [root@xroads /exampleset/ddset]# dd if=/dev/zero of=tmp bs=1024 count=1G @@ -57,9 +64,13 @@ Notice the difference between the system memory usage as reported by /proc/meminfo between the restricted cpuset case above and the unrestricted case (i.e. running the same 'dd' command without assigning it to a fake NUMA cpuset): - Unrestricted Restricted - MemTotal: 3091900 kB 3091900 kB - MemFree: 42113 kB 1513236 kB + + ======== ============ ========== + Name Unrestricted Restricted + ======== ============ ========== + MemTotal 3091900 kB 3091900 kB + MemFree 42113 kB 1513236 kB + ======== ============ ========== This allows for coarse memory management for the tasks you assign to particular cpusets. Since cpusets can form a hierarchy, you can create some pretty diff --git a/Documentation/x86/x86_64/index.rst b/Documentation/x86/x86_64/index.rst index 7b8c82151358..e2a324cde671 100644 --- a/Documentation/x86/x86_64/index.rst +++ b/Documentation/x86/x86_64/index.rst @@ -11,3 +11,4 @@ x86_64 Support uefi mm 5level-paging + fake-numa-for-cpusets |