evie/android_kernel_oneplus_msm8998
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cpuset: cleanup cpuset[_can]_attach()

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cpuset_can_attach() prepare global variables cpus_attach and
cpuset_attach_nodemask_{to|from} which are used by cpuset_attach().
There is no reason to prepare in cpuset_can_attach().  The same
information can be accessed from cpuset_attach().

Move the prepartion logic from cpuset_can_attach() to cpuset_attach()
and make the global variables static ones inside cpuset_attach().

With this change, there's no reason to keep
cpuset_attach_nodemask_{from|to} global.  Move them inside
cpuset_attach().  Unfortunately, we need to keep cpus_attach global as
it can't be allocated from cpuset_attach().

v2: cpus_attach not converted to cpumask_t as per Li Zefan and Rusty
    Russell.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Tejun Heo 2013-01-07 08:51:07 -08:00
parent ae8086ce15
commit 4e4c9a140f
1 changed files with 22 additions and 21 deletions
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43
kernel/cpuset.c
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@ -1395,15 +1395,6 @@ static int fmeter_getrate(struct fmeter *fmp)
return val; return val;
} }
/*
* Protected by cgroup_lock. The nodemasks must be stored globally because
* dynamically allocating them is not allowed in can_attach, and they must
* persist until attach.
*/
static cpumask_var_t cpus_attach;
static nodemask_t cpuset_attach_nodemask_from;
static nodemask_t cpuset_attach_nodemask_to;
/* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */ /* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
{ {
@ -1430,6 +1421,28 @@ static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
return ret; return ret;
} }
return 0;
}
/*
* Protected by cgroup_mutex. cpus_attach is used only by cpuset_attach()
* but we can't allocate it dynamically there. Define it global and
* allocate from cpuset_init().
*/
static cpumask_var_t cpus_attach;
static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
{
/* static bufs protected by cgroup_mutex */
static nodemask_t cpuset_attach_nodemask_from;
static nodemask_t cpuset_attach_nodemask_to;
struct mm_struct *mm;
struct task_struct *task;
struct task_struct *leader = cgroup_taskset_first(tset);
struct cgroup *oldcgrp = cgroup_taskset_cur_cgroup(tset);
struct cpuset *cs = cgroup_cs(cgrp);
struct cpuset *oldcs = cgroup_cs(oldcgrp);
/* prepare for attach */ /* prepare for attach */
if (cs == &top_cpuset) if (cs == &top_cpuset)
cpumask_copy(cpus_attach, cpu_possible_mask); cpumask_copy(cpus_attach, cpu_possible_mask);
@ -1438,18 +1451,6 @@ static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
guarantee_online_mems(cs, &cpuset_attach_nodemask_to); guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
return 0;
}
static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
{
struct mm_struct *mm;
struct task_struct *task;
struct task_struct *leader = cgroup_taskset_first(tset);
struct cgroup *oldcgrp = cgroup_taskset_cur_cgroup(tset);
struct cpuset *cs = cgroup_cs(cgrp);
struct cpuset *oldcs = cgroup_cs(oldcgrp);
cgroup_taskset_for_each(task, cgrp, tset) { cgroup_taskset_for_each(task, cgrp, tset) {
/* /*
* can_attach beforehand should guarantee that this doesn't * can_attach beforehand should guarantee that this doesn't