linux/kernel/cpuset.c, branch v3.18

Merge branch 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2014-10-10T11:24:40Z

Pull cgroup updates from Tejun Heo: "Nothing too interesting. Just a handful of cleanup patches" * 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: Revert "cgroup: remove redundant variable in cgroup_mount()" cgroup: remove redundant variable in cgroup_mount() cgroup: fix missing unlock in cgroup_release_agent() cgroup: remove CGRP_RELEASABLE flag perf/cgroup: Remove perf_put_cgroup() cgroup: remove redundant check in cgroup_ino() cpuset: simplify proc_cpuset_show() cgroup: simplify proc_cgroup_show() cgroup: use a per-cgroup work for release agent cgroup: remove bogus comments cgroup: remove redundant code in cgroup_rmdir() cgroup: remove some useless forward declarations cgroup: fix a typo in comment.

cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags

2014-09-25T02:16:06Z

When we change cpuset.memory_spread_{page,slab}, cpuset will flip PF_SPREAD_{PAGE,SLAB} bit of tsk->flags for each task in that cpuset. This should be done using atomic bitops, but currently we don't, which is broken. Tetsuo reported a hard-to-reproduce kernel crash on RHEL6, which happened when one thread tried to clear PF_USED_MATH while at the same time another thread tried to flip PF_SPREAD_PAGE/PF_SPREAD_SLAB. They both operate on the same task. Here's the full report: https://lkml.org/lkml/2014/9/19/230 To fix this, we make PF_SPREAD_PAGE and PF_SPREAD_SLAB atomic flags. v4: - updated mm/slab.c. (Fengguang Wu) - updated Documentation. Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Miao Xie Cc: Kees Cook Fixes: 950592f7b991 ("cpusets: update tasks' page/slab spread flags in time") Cc: # 2.6.31+ Reported-by: Tetsuo Handa Signed-off-by: Zefan Li Signed-off-by: Tejun Heo

cpuset: simplify proc_cpuset_show()

2014-09-18T17:27:23Z

Use the ONE macro instead of REG, and we can simplify proc_cpuset_show(). Signed-off-by: Zefan Li Signed-off-by: Tejun Heo

Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2014-08-04T17:11:28Z

Pull cgroup changes from Tejun Heo: "Mostly changes to get the v2 interface ready. The core features are mostly ready now and I think it's reasonable to expect to drop the devel mask in one or two devel cycles at least for a subset of controllers. - cgroup added a controller dependency mechanism so that block cgroup can depend on memory cgroup. This will be used to finally support IO provisioning on the writeback traffic, which is currently being implemented. - The v2 interface now uses a separate table so that the interface files for the new interface are explicitly declared in one place. Each controller will explicitly review and add the files for the new interface. - cpuset is getting ready for the hierarchical behavior which is in the similar style with other controllers so that an ancestor's configuration change doesn't change the descendants' configurations irreversibly and processes aren't silently migrated when a CPU or node goes down. All the changes are to the new interface and no behavior changed for the multiple hierarchies" * 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (29 commits) cpuset: fix the WARN_ON() in update_nodemasks_hier() cgroup: initialize cgrp_dfl_root_inhibit_ss_mask from !->dfl_files test cgroup: make CFTYPE_ONLY_ON_DFL and CFTYPE_NO_ internal to cgroup core cgroup: distinguish the default and legacy hierarchies when handling cftypes cgroup: replace cgroup_add_cftypes() with cgroup_add_legacy_cftypes() cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes cgroup: split cgroup_base_files[] into cgroup_{dfl|legacy}_base_files[] cpuset: export effective masks to userspace cpuset: allow writing offlined masks to cpuset.cpus/mems cpuset: enable onlined cpu/node in effective masks cpuset: refactor cpuset_hotplug_update_tasks() cpuset: make cs->{cpus, mems}_allowed as user-configured masks cpuset: apply cs->effective_{cpus,mems} cpuset: initialize top_cpuset's configured masks at mount cpuset: use effective cpumask to build sched domains cpuset: inherit ancestor's masks if effective_{cpus, mems} becomes empty cpuset: update cs->effective_{cpus, mems} when config changes cpuset: update cpuset->effective_{cpus,mems} at hotplug cpuset: add cs->effective_cpus and cs->effective_mems cgroup: clean up sane_behavior handling ...

cpuset: fix the WARN_ON() in update_nodemasks_hier()

2014-07-30T15:26:58Z

The WARN_ON() is used to check if we break the legal hierarchy, on which the effective mems should be equal to configured mems. Reported-by: Mike Qiu Tested-by: Mike Qiu Signed-off-by: Li Zefan

cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes

2014-07-15T15:05:09Z

Currently, cgroup_subsys->base_cftypes is used for both the unified default hierarchy and legacy ones and subsystems can mark each file with either CFTYPE_ONLY_ON_DFL or CFTYPE_INSANE if it has to appear only on one of them. This is quite hairy and error-prone. Also, we may end up exposing interface files to the default hierarchy without thinking it through. cgroup_subsys will grow two separate cftype arrays and apply each only on the hierarchies of the matching type. This will allow organizing cftypes in a lot clearer way and encourage subsystems to scrutinize the interface which is being exposed in the new default hierarchy. In preparation, this patch renames cgroup_subsys->base_cftypes to cgroup_subsys->legacy_cftypes. This patch is pure rename. Signed-off-by: Tejun Heo Acked-by: Neil Horman Acked-by: Li Zefan Cc: Johannes Weiner Cc: Michal Hocko Cc: Vivek Goyal Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Aristeu Rozanski Cc: Aneesh Kumar K.V

cpuset: export effective masks to userspace

2014-07-09T19:56:18Z

cpuset.cpus and cpuset.mems are the configured masks, and we need to export effective masks to userspace, so users know the real cpus_allowed and mems_allowed that apply to the tasks in a cpuset. v2: - export those masks unconditionally, suggested by Tejun. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo

cpuset: allow writing offlined masks to cpuset.cpus/mems

2014-07-09T19:56:17Z

As the configured masks won't be limited by its parent, and the top cpuset's masks won't change when hotplug happens, it's natural to allow writing offlined masks to the configured masks. If on default hierarchy: # echo 0 > /sys/devices/system/cpu/cpu1/online # mkdir /cpuset/sub # echo 1 > /cpuset/sub/cpuset.cpus # cat /cpuset/sub/cpuset.cpus 1 If on legacy hierarchy: # echo 0 > /sys/devices/system/cpu/cpu1/online # mkdir /cpuset/sub # echo 1 > /cpuset/sub/cpuset.cpus -bash: echo: write error: Invalid argument Note the checks don't need to be gated by cgroup_on_dfl, because we've initialized top_cpuset.{cpus,mems}_allowed accordingly in cpuset_bind(). Signed-off-by: Li Zefan Signed-off-by: Tejun Heo

cpuset: enable onlined cpu/node in effective masks

2014-07-09T19:56:17Z

Firstly offline cpu1: # echo 0-1 > cpuset.cpus # echo 0 > /sys/devices/system/cpu/cpu1/online # cat cpuset.cpus 0-1 # cat cpuset.effective_cpus 0 Then online it: # echo 1 > /sys/devices/system/cpu/cpu1/online # cat cpuset.cpus 0-1 # cat cpuset.effective_cpus 0-1 And cpuset will bring it back to the effective mask. The implementation is quite straightforward. Instead of calculating the offlined cpus/mems and do updates, we just set the new effective_mask to online_mask & congifured_mask. This is a behavior change for default hierarchy, so legacy hierarchy won't be affected. v2: - make refactoring of cpuset_hotplug_update_tasks() as seperate patch, suggested by Tejun. - make hotplug_update_tasks_insane() use @new_cpus and @new_mems as hotplug_update_tasks_sane() does. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo

cpuset: refactor cpuset_hotplug_update_tasks()

2014-07-09T19:56:17Z

We mix the handling for both default hierarchy and legacy hierarchy in the same function, and it's quite messy, so split into two functions. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo