extract two functions from update_cpumask() and update_nodemask().They will be
used later for updating tasks' cpus_allowed and mems_allowed after CPU/NODE
offline/online.
Signed-off-by: Miao Xie <[email protected]>
Acked-by: Paul Jackson <[email protected]>
---
kernel/cpuset.c | 179 +++++++++++++++++++++++++++++++++----------------------
1 files changed, 108 insertions(+), 71 deletions(-)
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 86ea9e3..dc16f71 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -766,6 +766,37 @@ static void cpuset_change_cpumask(struct task_struct *tsk,
}
/**
+ * update_tasks_cpumask - Update the cpumasks of tasks in the cpuset.
+ * @cs: the cpuset in which each task's cpus_allowed mask needs to be changed
+ *
+ * Called with cgroup_mutex held
+ *
+ * The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
+ * calling callback functions for each.
+ *
+ * Return 0 if successful, -errno if not.
+ */
+static int update_tasks_cpumask(struct cpuset *cs)
+{
+ struct cgroup_scanner scan;
+ struct ptr_heap heap;
+ int retval;
+
+ retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, &started_after);
+ if (retval)
+ return retval;
+
+ scan.cg = cs->css.cgroup;
+ scan.test_task = cpuset_test_cpumask;
+ scan.process_task = cpuset_change_cpumask;
+ scan.heap = &heap;
+ retval = cgroup_scan_tasks(&scan);
+
+ heap_free(&heap);
+ return retval;
+}
+
+/**
* update_cpumask - update the cpus_allowed mask of a cpuset and all tasks in it
* @cs: the cpuset to consider
* @buf: buffer of cpu numbers written to this cpuset
@@ -773,8 +804,6 @@ static void cpuset_change_cpumask(struct task_struct *tsk,
static int update_cpumask(struct cpuset *cs, char *buf)
{
struct cpuset trialcs;
- struct cgroup_scanner scan;
- struct ptr_heap heap;
int retval;
int is_load_balanced;
@@ -807,10 +836,6 @@ static int update_cpumask(struct cpuset *cs, char *buf)
if (cpus_equal(cs->cpus_allowed, trialcs.cpus_allowed))
return 0;
- retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, &started_after);
- if (retval)
- return retval;
-
is_load_balanced = is_sched_load_balance(&trialcs);
mutex_lock(&callback_mutex);
@@ -821,12 +846,9 @@ static int update_cpumask(struct cpuset *cs, char *buf)
* Scan tasks in the cpuset, and update the cpumasks of any
* that need an update.
*/
- scan.cg = cs->css.cgroup;
- scan.test_task = cpuset_test_cpumask;
- scan.process_task = cpuset_change_cpumask;
- scan.heap = &heap;
- cgroup_scan_tasks(&scan);
- heap_free(&heap);
+ retval = update_tasks_cpumask(cs);
+ if (retval < 0)
+ return retval;
if (is_load_balanced)
rebuild_sched_domains();
@@ -882,72 +904,25 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from,
mutex_unlock(&callback_mutex);
}
-/*
- * Handle user request to change the 'mems' memory placement
- * of a cpuset. Needs to validate the request, update the
- * cpusets mems_allowed and mems_generation, and for each
- * task in the cpuset, rebind any vma mempolicies and if
- * the cpuset is marked 'memory_migrate', migrate the tasks
- * pages to the new memory.
- *
- * Call with cgroup_mutex held. May take callback_mutex during call.
- * Will take tasklist_lock, scan tasklist for tasks in cpuset cs,
- * lock each such tasks mm->mmap_sem, scan its vma's and rebind
- * their mempolicies to the cpusets new mems_allowed.
- */
-
static void *cpuset_being_rebound;
-static int update_nodemask(struct cpuset *cs, char *buf)
+/**
+ * update_tasks_nodemask - Update the nodemasks of tasks in the cpuset.
+ * @cs: the cpuset in which each task's mems_allowed mask needs to be changed
+ * @oldmem: old mems_allowed of cpuset cs
+ *
+ * Called with cgroup_mutex held
+ * Return 0 if successful, -errno if not.
+ */
+static int update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem)
{
- struct cpuset trialcs;
- nodemask_t oldmem;
struct task_struct *p;
struct mm_struct **mmarray;
int i, n, ntasks;
int migrate;
int fudge;
- int retval;
struct cgroup_iter it;
-
- /*
- * top_cpuset.mems_allowed tracks node_stats[N_HIGH_MEMORY];
- * it's read-only
- */
- if (cs == &top_cpuset)
- return -EACCES;
-
- trialcs = *cs;
-
- /*
- * An empty mems_allowed is ok iff there are no tasks in the cpuset.
- * Since nodelist_parse() fails on an empty mask, we special case
- * that parsing. The validate_change() call ensures that cpusets
- * with tasks have memory.
- */
- buf = strstrip(buf);
- if (!*buf) {
- nodes_clear(trialcs.mems_allowed);
- } else {
- retval = nodelist_parse(buf, trialcs.mems_allowed);
- if (retval < 0)
- goto done;
- }
- nodes_and(trialcs.mems_allowed, trialcs.mems_allowed,
- node_states[N_HIGH_MEMORY]);
- oldmem = cs->mems_allowed;
- if (nodes_equal(oldmem, trialcs.mems_allowed)) {
- retval = 0; /* Too easy - nothing to do */
- goto done;
- }
- retval = validate_change(cs, &trialcs);
- if (retval < 0)
- goto done;
-
- mutex_lock(&callback_mutex);
- cs->mems_allowed = trialcs.mems_allowed;
- cs->mems_generation = cpuset_mems_generation++;
- mutex_unlock(&callback_mutex);
+ int retval;
cpuset_being_rebound = cs; /* causes mpol_dup() rebind */
@@ -1014,7 +989,7 @@ static int update_nodemask(struct cpuset *cs, char *buf)
mpol_rebind_mm(mm, &cs->mems_allowed);
if (migrate)
- cpuset_migrate_mm(mm, &oldmem, &cs->mems_allowed);
+ cpuset_migrate_mm(mm, oldmem, &cs->mems_allowed);
mmput(mm);
}
@@ -1026,6 +1001,69 @@ done:
return retval;
}
+/*
+ * Handle user request to change the 'mems' memory placement
+ * of a cpuset. Needs to validate the request, update the
+ * cpusets mems_allowed and mems_generation, and for each
+ * task in the cpuset, rebind any vma mempolicies and if
+ * the cpuset is marked 'memory_migrate', migrate the tasks
+ * pages to the new memory.
+ *
+ * Call with cgroup_mutex held. May take callback_mutex during call.
+ * Will take tasklist_lock, scan tasklist for tasks in cpuset cs,
+ * lock each such tasks mm->mmap_sem, scan its vma's and rebind
+ * their mempolicies to the cpusets new mems_allowed.
+ */
+static int update_nodemask(struct cpuset *cs, char *buf)
+{
+ struct cpuset trialcs;
+ nodemask_t oldmem;
+ int retval;
+
+ /*
+ * top_cpuset.mems_allowed tracks node_stats[N_HIGH_MEMORY];
+ * it's read-only
+ */
+ if (cs == &top_cpuset)
+ return -EACCES;
+
+ trialcs = *cs;
+
+ /*
+ * An empty mems_allowed is ok iff there are no tasks in the cpuset.
+ * Since nodelist_parse() fails on an empty mask, we special case
+ * that parsing. The validate_change() call ensures that cpusets
+ * with tasks have memory.
+ */
+ buf = strstrip(buf);
+ if (!*buf) {
+ nodes_clear(trialcs.mems_allowed);
+ } else {
+ retval = nodelist_parse(buf, trialcs.mems_allowed);
+ if (retval < 0)
+ goto done;
+ }
+ nodes_and(trialcs.mems_allowed, trialcs.mems_allowed,
+ node_states[N_HIGH_MEMORY]);
+ oldmem = cs->mems_allowed;
+ if (nodes_equal(oldmem, trialcs.mems_allowed)) {
+ retval = 0; /* Too easy - nothing to do */
+ goto done;
+ }
+ retval = validate_change(cs, &trialcs);
+ if (retval < 0)
+ goto done;
+
+ mutex_lock(&callback_mutex);
+ cs->mems_allowed = trialcs.mems_allowed;
+ cs->mems_generation = cpuset_mems_generation++;
+ mutex_unlock(&callback_mutex);
+
+ retval = update_tasks_nodemask(cs, &oldmem);
+done:
+ return retval;
+}
+
int current_cpuset_is_being_rebound(void)
{
return task_cs(current) == cpuset_being_rebound;
@@ -1938,7 +1976,6 @@ void __init cpuset_init_smp(void)
}
/**
-
* cpuset_cpus_allowed - return cpus_allowed mask from a tasks cpuset.
* @tsk: pointer to task_struct from which to obtain cpuset->cpus_allowed.
* @pmask: pointer to cpumask_t variable to receive cpus_allowed set.
--
1.5.4.rc3
Good work, Miao.
Andrew - these two patches of Miao should be ready for you to consider now.
--
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <[email protected]> 1.940.382.4214
On Mon, 02 Jun 2008 16:31:05 +0800
Miao Xie <[email protected]> wrote:
> extract two functions from update_cpumask() and update_nodemask().They will be
> used later for updating tasks' cpus_allowed and mems_allowed after CPU/NODE
> offline/online.
Unfortunately this patch conflicts with
http://userweb.kernel.org/~akpm/mmotm/broken-out/cpusets-fix-bug-when-adding-nonexistent-cpu-or-mem.patch
Please check that the patch which I merged still makes sense. ie: that
we did not revert the effects of that bugfix.
Thanks.
Andrew Morton wrote:
> On Mon, 02 Jun 2008 16:31:05 +0800
> Miao Xie <[email protected]> wrote:
>
>> extract two functions from update_cpumask() and update_nodemask().They will be
>> used later for updating tasks' cpus_allowed and mems_allowed after CPU/NODE
>> offline/online.
>
> Unfortunately this patch conflicts with
> http://userweb.kernel.org/~akpm/mmotm/broken-out/cpusets-fix-bug-when-adding-nonexistent-cpu-or-mem.patch
>
> Please check that the patch which I merged still makes sense. ie: that
> we did not revert the effects of that bugfix.
>
They are fixing 2 different bugs, so they are irrelated, but unfortunately conflict in
the code due to Miao's first patch which does code restructuring.
on 2008-6-4 8:55 Li Zefan wrote:
> Andrew Morton wrote:
>> On Mon, 02 Jun 2008 16:31:05 +0800
>> Miao Xie <[email protected]> wrote:
>>
>>> extract two functions from update_cpumask() and update_nodemask().They will be
>>> used later for updating tasks' cpus_allowed and mems_allowed after CPU/NODE
>>> offline/online.
>> Unfortunately this patch conflicts with
>> http://userweb.kernel.org/~akpm/mmotm/broken-out/cpusets-fix-bug-when-adding-nonexistent-cpu-or-mem.patch
>>
>> Please check that the patch which I merged still makes sense. ie: that
>> we did not revert the effects of that bugfix.
>>
>
> They are fixing 2 different bugs, so they are irrelated, but unfortunately conflict in
> the code due to Miao's first patch which does code restructuring.
>
Right. I will modify my patches.
On Wed, 04 Jun 2008 10:00:34 +0800 Miao Xie <[email protected]> wrote:
> on 2008-6-4 8:55 Li Zefan wrote:
> > Andrew Morton wrote:
> >> On Mon, 02 Jun 2008 16:31:05 +0800
> >> Miao Xie <[email protected]> wrote:
> >>
> >>> extract two functions from update_cpumask() and update_nodemask().They will be
> >>> used later for updating tasks' cpus_allowed and mems_allowed after CPU/NODE
> >>> offline/online.
> >> Unfortunately this patch conflicts with
> >> http://userweb.kernel.org/~akpm/mmotm/broken-out/cpusets-fix-bug-when-adding-nonexistent-cpu-or-mem.patch
> >>
> >> Please check that the patch which I merged still makes sense. ie: that
> >> we did not revert the effects of that bugfix.
> >>
> >
> > They are fixing 2 different bugs, so they are irrelated, but unfortunately conflict in
> > the code due to Miao's first patch which does code restructuring.
> >
>
> Right. I will modify my patches.
I already did that, didn't I?
Andrew Morton wrote:
> On Wed, 04 Jun 2008 10:00:34 +0800 Miao Xie <[email protected]> wrote:
>
>> on 2008-6-4 8:55 Li Zefan wrote:
>>> Andrew Morton wrote:
>>>> On Mon, 02 Jun 2008 16:31:05 +0800
>>>> Miao Xie <[email protected]> wrote:
>>>>
>>>>> extract two functions from update_cpumask() and update_nodemask().They will be
>>>>> used later for updating tasks' cpus_allowed and mems_allowed after CPU/NODE
>>>>> offline/online.
>>>> Unfortunately this patch conflicts with
>>>> http://userweb.kernel.org/~akpm/mmotm/broken-out/cpusets-fix-bug-when-adding-nonexistent-cpu-or-mem.patch
>>>>
>>>> Please check that the patch which I merged still makes sense. ie: that
>>>> we did not revert the effects of that bugfix.
>>>>
>>> They are fixing 2 different bugs, so they are irrelated, but unfortunately conflict in
>>> the code due to Miao's first patch which does code restructuring.
>>>
>> Right. I will modify my patches.
>
> I already did that, didn't I?
>
Oh, I just had a look at that, and yes you did that, but in a wrong way. :(
You reverted the effects of this bugfix:
cpusets-fix-bug-when-adding-nonexistent-cpu-or-mem.patch
Andrew wrote:
> I already did that, didn't I?
Where can I find your attempted merge, Andrew?
Probably someplace I should know about ... sorry.
--
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <[email protected]> 1.940.382.4214
On Tue, 3 Jun 2008 21:59:17 -0500 Paul Jackson <[email protected]> wrote:
> Andrew wrote:
> > I already did that, didn't I?
>
> Where can I find your attempted merge, Andrew?
>
> Probably someplace I should know about ... sorry.
>
Who are you and what do you have to do with cpusets?
Sigh, sorry. I need to drop and redo them anyway.
On Tue, 3 Jun 2008 21:00:38 -0700 Andrew Morton <[email protected]> wrote:
> On Tue, 3 Jun 2008 21:59:17 -0500 Paul Jackson <[email protected]> wrote:
>
> > Andrew wrote:
> > > I already did that, didn't I?
> >
> > Where can I find your attempted merge, Andrew?
> >
> > Probably someplace I should know about ... sorry.
> >
>
> Who are you and what do you have to do with cpusets?
>
> Sigh, sorry. I need to drop and redo them anyway.
hey, who are you calling senile? You were cc'ed.
Andrew, replying to Andrew:
> > Sigh, sorry. I need to drop and redo them anyway.
>
> hey, who are you calling senile? You were cc'ed.
... once again demonstrating that Aussies a sense of humor
beyond the grasp of the rest of us mere mortals.
--
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <[email protected]> 1.940.382.4214
On Mon, 02 Jun 2008 16:31:05 +0800 Miao Xie <[email protected]> wrote:
> extract two functions from update_cpumask() and update_nodemask().They will be
> used later for updating tasks' cpus_allowed and mems_allowed after CPU/NODE
> offline/online.
>
> Signed-off-by: Miao Xie <[email protected]>
> Acked-by: Paul Jackson <[email protected]>
This patch has problems.
kernel/cpuset.c: In function 'cpuset_write_resmask':
kernel/cpuset.c:1374: warning: passing argument 2 of 'update_nodemask' discards qualifiers from pointer target type
Did you not get this warning also?
I don't know how to fix it. cftype.write_string() requires a const
char* in the third arg, but we then go on to call update_nodemask(),
which does a strstrip() on this allegedly-const char array.
Taking a copy of the string in update_nodemask() would fix things, but
that's pretty lame.
Andrew Morton wrote:
> On Mon, 02 Jun 2008 16:31:05 +0800 Miao Xie <[email protected]> wrote:
>
>> extract two functions from update_cpumask() and update_nodemask().They will be
>> used later for updating tasks' cpus_allowed and mems_allowed after CPU/NODE
>> offline/online.
>>
>> Signed-off-by: Miao Xie <[email protected]>
>> Acked-by: Paul Jackson <[email protected]>
>
> This patch has problems.
>
> kernel/cpuset.c: In function 'cpuset_write_resmask':
> kernel/cpuset.c:1374: warning: passing argument 2 of 'update_nodemask' discards qualifiers from pointer target type
>
> Did you not get this warning also?
>
> I don't know how to fix it. cftype.write_string() requires a const
> char* in the third arg, but we then go on to call update_nodemask(),
> which does a strstrip() on this allegedly-const char array.
>
That strstrip() should be removed. because cgroup_write_string() already strstrip()ed
the buffer. Paul M's original patch removed that 2 strstrip()s in cpuset.c.
> Taking a copy of the string in update_nodemask() would fix things, but
> that's pretty lame.
>
>> kernel/cpuset.c: In function 'cpuset_write_resmask':
>> kernel/cpuset.c:1374: warning: passing argument 2 of 'update_nodemask' discards qualifiers from pointer target type
>>
>> Did you not get this warning also?
>>
>> I don't know how to fix it. cftype.write_string() requires a const
>> char* in the third arg, but we then go on to call update_nodemask(),
>> which does a strstrip() on this allegedly-const char array.
>>
>
> That strstrip() should be removed. because cgroup_write_string() already strstrip()ed
> the buffer. Paul M's original patch removed that 2 strstrip()s in cpuset.c.
>
Here is the patch:
--- linux-2.6.26-rc7/kernel/cpuset.c.bak 2008-07-02 17:53:07.000000000 +0800
+++ linux-2.6.26-rc7/kernel/cpuset.c 2008-07-02 17:53:23.000000000 +0800
@@ -1011,7 +1011,7 @@ done:
* lock each such tasks mm->mmap_sem, scan its vma's and rebind
* their mempolicies to the cpusets new mems_allowed.
*/
-static int update_nodemask(struct cpuset *cs, char *buf)
+static int update_nodemask(struct cpuset *cs, const char *buf)
{
struct cpuset trialcs;
nodemask_t oldmem;
@@ -1032,7 +1032,6 @@ static int update_nodemask(struct cpuset
* that parsing. The validate_change() call ensures that cpusets
* with tasks have memory.
*/
- buf = strstrip(buf);
if (!*buf) {
nodes_clear(trialcs.mems_allowed);
} else {
>> Taking a copy of the string in update_nodemask() would fix things, but
>> that's pretty lame.
>>