The patch titled
Cpuset hardwall flag: add a mem_hardwall flag to cpusets
has been removed from the -mm tree. Its filename was
cpuset-hardwall-flag-add-a-mem_hardwall-flag-to-cpusets.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: Cpuset hardwall flag: add a mem_hardwall flag to cpusets
From: Paul Menage <menage@xxxxxxxxxx>
This flag provides the hardwalling properties of mem_exclusive, without
enforcing the exclusivity. Either mem_hardwall or mem_exclusive is sufficient
to prevent GFP_KERNEL allocations from passing outside the cpuset's assigned
nodes.
Signed-off-by: Paul Menage <menage@xxxxxxxxxx>
Acked-by: Paul Jackson <pj@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/cpusets.txt | 26 ++++++++++---------
kernel/cpuset.c | 48 ++++++++++++++++++++++++------------
2 files changed, 46 insertions(+), 28 deletions(-)
diff -puN Documentation/cpusets.txt~cpuset-hardwall-flag-add-a-mem_hardwall-flag-to-cpusets Documentation/cpusets.txt
--- a/Documentation/cpusets.txt~cpuset-hardwall-flag-add-a-mem_hardwall-flag-to-cpusets
+++ a/Documentation/cpusets.txt
@@ -171,6 +171,7 @@ files describing that cpuset:
- memory_migrate flag: if set, move pages to cpusets nodes
- cpu_exclusive flag: is cpu placement exclusive?
- mem_exclusive flag: is memory placement exclusive?
+ - mem_hardwall flag: is memory allocation hardwalled
- memory_pressure: measure of how much paging pressure in cpuset
In addition, the root cpuset only has the following file:
@@ -222,17 +223,18 @@ If a cpuset is cpu or mem exclusive, no
a direct ancestor or descendent, may share any of the same CPUs or
Memory Nodes.
-A cpuset that is mem_exclusive restricts kernel allocations for
-page, buffer and other data commonly shared by the kernel across
-multiple users. All cpusets, whether mem_exclusive or not, restrict
-allocations of memory for user space. This enables configuring a
-system so that several independent jobs can share common kernel data,
-such as file system pages, while isolating each jobs user allocation in
-its own cpuset. To do this, construct a large mem_exclusive cpuset to
-hold all the jobs, and construct child, non-mem_exclusive cpusets for
-each individual job. Only a small amount of typical kernel memory,
-such as requests from interrupt handlers, is allowed to be taken
-outside even a mem_exclusive cpuset.
+A cpuset that is mem_exclusive *or* mem_hardwall is "hardwalled",
+i.e. it restricts kernel allocations for page, buffer and other data
+commonly shared by the kernel across multiple users. All cpusets,
+whether hardwalled or not, restrict allocations of memory for user
+space. This enables configuring a system so that several independent
+jobs can share common kernel data, such as file system pages, while
+isolating each job's user allocation in its own cpuset. To do this,
+construct a large mem_exclusive cpuset to hold all the jobs, and
+construct child, non-mem_exclusive cpusets for each individual job.
+Only a small amount of typical kernel memory, such as requests from
+interrupt handlers, is allowed to be taken outside even a
+mem_exclusive cpuset.
1.5 What is memory_pressure ?
@@ -707,7 +709,7 @@ Now you want to do something with this c
In this directory you can find several files:
# ls
-cpus cpu_exclusive mems mem_exclusive tasks
+cpus cpu_exclusive mems mem_exclusive mem_hardwall tasks
Reading them will give you information about the state of this cpuset:
the CPUs and Memory Nodes it can use, the processes that are using
diff -puN kernel/cpuset.c~cpuset-hardwall-flag-add-a-mem_hardwall-flag-to-cpusets kernel/cpuset.c
--- a/kernel/cpuset.c~cpuset-hardwall-flag-add-a-mem_hardwall-flag-to-cpusets
+++ a/kernel/cpuset.c
@@ -127,6 +127,7 @@ struct cpuset_hotplug_scanner {
typedef enum {
CS_CPU_EXCLUSIVE,
CS_MEM_EXCLUSIVE,
+ CS_MEM_HARDWALL,
CS_MEMORY_MIGRATE,
CS_SCHED_LOAD_BALANCE,
CS_SPREAD_PAGE,
@@ -144,6 +145,11 @@ static inline int is_mem_exclusive(const
return test_bit(CS_MEM_EXCLUSIVE, &cs->flags);
}
+static inline int is_mem_hardwall(const struct cpuset *cs)
+{
+ return test_bit(CS_MEM_HARDWALL, &cs->flags);
+}
+
static inline int is_sched_load_balance(const struct cpuset *cs)
{
return test_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
@@ -1042,12 +1048,9 @@ static int update_relax_domain_level(str
/*
* update_flag - read a 0 or a 1 in a file and update associated flag
- * bit: the bit to update (CS_CPU_EXCLUSIVE, CS_MEM_EXCLUSIVE,
- * CS_SCHED_LOAD_BALANCE,
- * CS_NOTIFY_ON_RELEASE, CS_MEMORY_MIGRATE,
- * CS_SPREAD_PAGE, CS_SPREAD_SLAB)
- * cs: the cpuset to update
- * buf: the buffer where we read the 0 or 1
+ * bit: the bit to update (see cpuset_flagbits_t)
+ * cs: the cpuset to update
+ * turning_on: whether the flag is being set or cleared
*
* Call with cgroup_mutex held.
*/
@@ -1228,6 +1231,7 @@ typedef enum {
FILE_MEMLIST,
FILE_CPU_EXCLUSIVE,
FILE_MEM_EXCLUSIVE,
+ FILE_MEM_HARDWALL,
FILE_SCHED_LOAD_BALANCE,
FILE_SCHED_RELAX_DOMAIN_LEVEL,
FILE_MEMORY_PRESSURE_ENABLED,
@@ -1312,6 +1316,9 @@ static int cpuset_write_u64(struct cgrou
case FILE_MEM_EXCLUSIVE:
retval = update_flag(CS_MEM_EXCLUSIVE, cs, val);
break;
+ case FILE_MEM_HARDWALL:
+ retval = update_flag(CS_MEM_HARDWALL, cs, val);
+ break;
case FILE_SCHED_LOAD_BALANCE:
retval = update_flag(CS_SCHED_LOAD_BALANCE, cs, val);
break;
@@ -1422,6 +1429,8 @@ static u64 cpuset_read_u64(struct cgroup
return is_cpu_exclusive(cs);
case FILE_MEM_EXCLUSIVE:
return is_mem_exclusive(cs);
+ case FILE_MEM_HARDWALL:
+ return is_mem_hardwall(cs);
case FILE_SCHED_LOAD_BALANCE:
return is_sched_load_balance(cs);
case FILE_MEMORY_MIGRATE:
@@ -1474,6 +1483,13 @@ static struct cftype files[] = {
},
{
+ .name = "mem_hardwall",
+ .read_u64 = cpuset_read_u64,
+ .write_u64 = cpuset_write_u64,
+ .private = FILE_MEM_HARDWALL,
+ },
+
+ {
.name = "sched_load_balance",
.read_u64 = cpuset_read_u64,
.write_u64 = cpuset_write_u64,
@@ -1962,14 +1978,14 @@ int cpuset_nodemask_valid_mems_allowed(n
}
/*
- * nearest_exclusive_ancestor() - Returns the nearest mem_exclusive
- * ancestor to the specified cpuset. Call holding callback_mutex.
- * If no ancestor is mem_exclusive (an unusual configuration), then
- * returns the root cpuset.
+ * nearest_hardwall_ancestor() - Returns the nearest mem_exclusive or
+ * mem_hardwall ancestor to the specified cpuset. Call holding
+ * callback_mutex. If no ancestor is mem_exclusive or mem_hardwall
+ * (an unusual configuration), then returns the root cpuset.
*/
-static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs)
+static const struct cpuset *nearest_hardwall_ancestor(const struct cpuset *cs)
{
- while (!is_mem_exclusive(cs) && cs->parent)
+ while (!(is_mem_exclusive(cs) || is_mem_hardwall(cs)) && cs->parent)
cs = cs->parent;
return cs;
}
@@ -1983,7 +1999,7 @@ static const struct cpuset *nearest_excl
* __GFP_THISNODE is set, yes, we can always allocate. If zone
* z's node is in our tasks mems_allowed, yes. If it's not a
* __GFP_HARDWALL request and this zone's nodes is in the nearest
- * mem_exclusive cpuset ancestor to this tasks cpuset, yes.
+ * hardwalled cpuset ancestor to this tasks cpuset, yes.
* If the task has been OOM killed and has access to memory reserves
* as specified by the TIF_MEMDIE flag, yes.
* Otherwise, no.
@@ -2006,7 +2022,7 @@ static const struct cpuset *nearest_excl
* and do not allow allocations outside the current tasks cpuset
* unless the task has been OOM killed as is marked TIF_MEMDIE.
* GFP_KERNEL allocations are not so marked, so can escape to the
- * nearest enclosing mem_exclusive ancestor cpuset.
+ * nearest enclosing hardwalled ancestor cpuset.
*
* Scanning up parent cpusets requires callback_mutex. The
* __alloc_pages() routine only calls here with __GFP_HARDWALL bit
@@ -2029,7 +2045,7 @@ static const struct cpuset *nearest_excl
* in_interrupt - any node ok (current task context irrelevant)
* GFP_ATOMIC - any node ok
* TIF_MEMDIE - any node ok
- * GFP_KERNEL - any node in enclosing mem_exclusive cpuset ok
+ * GFP_KERNEL - any node in enclosing hardwalled cpuset ok
* GFP_USER - only nodes in current tasks mems allowed ok.
*
* Rule:
@@ -2066,7 +2082,7 @@ int __cpuset_zone_allowed_softwall(struc
mutex_lock(&callback_mutex);
task_lock(current);
- cs = nearest_exclusive_ancestor(task_cs(current));
+ cs = nearest_hardwall_ancestor(task_cs(current));
task_unlock(current);
allowed = node_isset(node, cs->mems_allowed);
_
Patches currently in -mm which might be from menage@xxxxxxxxxx are
origin.patch
disable-the-memory-controller-by-default-v3.patch
add-a-refcount-check-in-dput.patch
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