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author | Li Zefan <lizefan@huawei.com> | 2014-07-09 10:47:29 +0200 |
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committer | Tejun Heo <tj@kernel.org> | 2014-07-09 21:56:16 +0200 |
commit | 734d45130cb4f668fb33d182f6943523628582ef (patch) | |
tree | d13a09fb59491e64e7cf147823d54373192dcab9 /samples | |
parent | cpuset: update cpuset->effective_{cpus,mems} at hotplug (diff) | |
download | linux-734d45130cb4f668fb33d182f6943523628582ef.tar.xz linux-734d45130cb4f668fb33d182f6943523628582ef.zip |
cpuset: update cs->effective_{cpus, mems} when config changes
We're going to have separate user-configured masks and effective ones.
Eventually configured masks can only be changed by writing cpuset.cpus
and cpuset.mems, and they won't be restricted by parent cpuset. While
effective masks reflect cpu/memory hotplug and hierachical restriction,
and these are the real masks that apply to the tasks in the cpuset.
We calculate effective mask this way:
- top cpuset's effective_mask == online_mask, otherwise
- cpuset's effective_mask == configured_mask & parent effective_mask,
if the result is empty, it inherits parent effective mask.
Those behavior changes are for default hierarchy only. For legacy
hierarchy, effective_mask and configured_mask are the same, so we won't
break old interfaces.
To make cs->effective_{cpus,mems} to be effective masks, we need to
- update the effective masks at hotplug
- update the effective masks at config change
- take on ancestor's mask when the effective mask is empty
The second item is done here. We don't need to treat root_cs specially
in update_cpumasks_hier().
This won't introduce behavior change.
v3:
- add a WARN_ON() to check if effective masks are the same with configured
masks on legacy hierarchy.
- pass trialcs->cpus_allowed to update_cpumasks_hier() and add a comment for
it. Similar change for update_nodemasks_hier(). Suggested by Tejun.
v2:
- revise the comment in update_{cpu,node}masks_hier(), suggested by Tejun.
- fix to use @cp instead of @cs in these two functions.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'samples')
0 files changed, 0 insertions, 0 deletions