The patch titled
Memoryless Nodes: use "node_memory_map" for cpusets
has been added to the -mm tree. Its filename is
memoryless-nodes-use-node_memory_map-for-cpusets.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Memoryless Nodes: use "node_memory_map" for cpusets
From: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
Against 2.6.22-rc1-mm1 atop Christoph Lameter's memoryless nodes series
take 2:
+ replaced node_online_map in cpuset_current_mems_allowed()
with node_states[N_MEMORY]
+ replaced node_online_map in cpuset_init_smp() with
node_states[N_MEMORY]
take 3:
+ fix up comments and top level cpuset tracking of nodes
with memory [instead of on-line nodes]
take 4:
+ fix typo in !CPUSETS definition of cpuset_current_mems_allowed()
+ fix up Documentation/cpusets.txt to reflect these changes.
cpusets try to ensure that any node added to a cpuset's mems_allowed is
on-line and contains memory. The assumption was that online nodes contained
memory. Thus, it is possible to add memoryless nodes to a cpuset and then add
tasks to this cpuset. This results in continuous series of oom-kill and
apparent system hang.
Change cpusets to use node_states[N_MEMORY] [a.k.a. node_memory_map] in place
of node_online_map when vetting memories. Return error if admin attempts to
write a non-empty mems_allowed node mask containing only memoryless-nodes.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
Signed-off-by: Bob Picco <bob.picco@xxxxxx>
Signed-off-by: Nishanth Aravamudan <nacc@xxxxxxxxxx>
Tested-by: Nishanth Aravamudan <nacc@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/cpusets.txt | 8 +++--
include/linux/cpuset.h | 2 -
kernel/cpuset.c | 51 +++++++++++++++++++++++-------------
3 files changed, 39 insertions(+), 22 deletions(-)
diff -puN Documentation/cpusets.txt~memoryless-nodes-use-node_memory_map-for-cpusets Documentation/cpusets.txt
--- a/Documentation/cpusets.txt~memoryless-nodes-use-node_memory_map-for-cpusets
+++ a/Documentation/cpusets.txt
@@ -7,6 +7,7 @@ Written by Simon.Derr@xxxxxxxx
Portions Copyright (c) 2004-2006 Silicon Graphics, Inc.
Modified by Paul Jackson <pj@xxxxxxx>
Modified by Christoph Lameter <clameter@xxxxxxx>
+Modified by Lee Schermerhorn <lee.schermerhorn@xxxxxx>
CONTENTS:
=========
@@ -35,7 +36,8 @@ CONTENTS:
----------------------
Cpusets provide a mechanism for assigning a set of CPUs and Memory
-Nodes to a set of tasks.
+Nodes to a set of tasks. In this document "Memory Node" refers to
+an on-line node that contains memory.
Cpusets constrain the CPU and Memory placement of tasks to only
the resources within a tasks current cpuset. They form a nested
@@ -220,8 +222,8 @@ and name space for cpusets, with a minim
The cpus and mems files in the root (top_cpuset) cpuset are
read-only. The cpus file automatically tracks the value of
cpu_online_map using a CPU hotplug notifier, and the mems file
-automatically tracks the value of node_online_map using the
-cpuset_track_online_nodes() hook.
+automatically tracks the value of node_states[N_MEMORY]--i.e.,
+nodes with memory--using the cpuset_track_online_nodes() hook.
1.4 What are exclusive cpusets ?
diff -puN include/linux/cpuset.h~memoryless-nodes-use-node_memory_map-for-cpusets include/linux/cpuset.h
--- a/include/linux/cpuset.h~memoryless-nodes-use-node_memory_map-for-cpusets
+++ a/include/linux/cpuset.h
@@ -93,7 +93,7 @@ static inline nodemask_t cpuset_mems_all
return node_possible_map;
}
-#define cpuset_current_mems_allowed (node_online_map)
+#define cpuset_current_mems_allowed (node_states[N_MEMORY])
static inline void cpuset_init_current_mems_allowed(void) {}
static inline void cpuset_update_task_memory_state(void) {}
#define cpuset_nodes_subset_current_mems_allowed(nodes) (1)
diff -puN kernel/cpuset.c~memoryless-nodes-use-node_memory_map-for-cpusets kernel/cpuset.c
--- a/kernel/cpuset.c~memoryless-nodes-use-node_memory_map-for-cpusets
+++ a/kernel/cpuset.c
@@ -581,26 +581,26 @@ static void guarantee_online_cpus(const
/*
* Return in *pmask the portion of a cpusets's mems_allowed that
- * are online. If none are online, walk up the cpuset hierarchy
- * until we find one that does have some online mems. If we get
- * all the way to the top and still haven't found any online mems,
- * return node_online_map.
+ * are online, with memory. If none are online with memory, walk
+ * up the cpuset hierarchy until we find one that does have some
+ * online mems. If we get all the way to the top and still haven't
+ * found any online mems, return node_states[N_MEMORY].
*
* One way or another, we guarantee to return some non-empty subset
- * of node_online_map.
+ * of node_states[N_MEMORY].
*
* Call with callback_mutex held.
*/
static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask)
{
- while (cs && !nodes_intersects(cs->mems_allowed, node_online_map))
+ while (cs && !nodes_intersects(cs->mems_allowed, node_states[N_MEMORY]))
cs = cs->parent;
if (cs)
- nodes_and(*pmask, cs->mems_allowed, node_online_map);
+ nodes_and(*pmask, cs->mems_allowed, node_states[N_MEMORY]);
else
- *pmask = node_online_map;
- BUG_ON(!nodes_intersects(*pmask, node_online_map));
+ *pmask = node_states[N_MEMORY];
+ BUG_ON(!nodes_intersects(*pmask, node_states[N_MEMORY]));
}
/**
@@ -924,7 +924,7 @@ static int update_nodemask(struct cpuset
int fudge;
int retval;
- /* top_cpuset.mems_allowed tracks node_online_map; it's read-only */
+ /* top_cpuset.mems_allowed tracks node_states[N_MEMORY]; it's read-only */
if (cs == &top_cpuset)
return -EACCES;
@@ -941,8 +941,21 @@ static int update_nodemask(struct cpuset
retval = nodelist_parse(buf, trialcs.mems_allowed);
if (retval < 0)
goto done;
+ if (!nodes_intersects(trialcs.mems_allowed,
+ node_states[N_MEMORY])) {
+ /*
+ * error if only memoryless nodes specified.
+ */
+ retval = -ENOSPC;
+ goto done;
+ }
}
- nodes_and(trialcs.mems_allowed, trialcs.mems_allowed, node_online_map);
+ /*
+ * Exclude memoryless nodes. We know that trialcs.mems_allowed
+ * contains at least one node with memory.
+ */
+ nodes_and(trialcs.mems_allowed, trialcs.mems_allowed,
+ node_states[N_MEMORY]);
oldmem = cs->mems_allowed;
if (nodes_equal(oldmem, trialcs.mems_allowed)) {
retval = 0; /* Too easy - nothing to do */
@@ -2098,8 +2111,9 @@ static void guarantee_online_cpus_mems_i
/*
* The cpus_allowed and mems_allowed nodemasks in the top_cpuset track
- * cpu_online_map and node_online_map. Force the top cpuset to track
- * whats online after any CPU or memory node hotplug or unplug event.
+ * cpu_online_map and node_states[N_MEMORY]. Force the top cpuset to
+ * track what's online after any CPU or memory node hotplug or unplug
+ * event.
*
* To ensure that we don't remove a CPU or node from the top cpuset
* that is currently in use by a child cpuset (which would violate
@@ -2119,7 +2133,7 @@ static void common_cpu_mem_hotplug_unplu
guarantee_online_cpus_mems_in_subtree(&top_cpuset);
top_cpuset.cpus_allowed = cpu_online_map;
- top_cpuset.mems_allowed = node_online_map;
+ top_cpuset.mems_allowed = node_states[N_MEMORY];
mutex_unlock(&callback_mutex);
mutex_unlock(&manage_mutex);
@@ -2147,8 +2161,9 @@ static int cpuset_handle_cpuhp(struct no
#ifdef CONFIG_MEMORY_HOTPLUG
/*
- * Keep top_cpuset.mems_allowed tracking node_online_map.
- * Call this routine anytime after you change node_online_map.
+ * Keep top_cpuset.mems_allowed tracking node_states[N_MEMORY].
+ * Call this routine anytime after you change
+ * node_states[N_MEMORY].
* See also the previous routine cpuset_handle_cpuhp().
*/
@@ -2167,7 +2182,7 @@ void cpuset_track_online_nodes(void)
void __init cpuset_init_smp(void)
{
top_cpuset.cpus_allowed = cpu_online_map;
- top_cpuset.mems_allowed = node_online_map;
+ top_cpuset.mems_allowed = node_states[N_MEMORY];
hotcpu_notifier(cpuset_handle_cpuhp, 0);
}
@@ -2309,7 +2324,7 @@ void cpuset_init_current_mems_allowed(vo
*
* Description: Returns the nodemask_t mems_allowed of the cpuset
* attached to the specified @tsk. Guaranteed to return some non-empty
- * subset of node_online_map, even if this means going outside the
+ * subset of node_states[N_MEMORY], even if this means going outside the
* tasks cpuset.
**/
_
Patches currently in -mm which might be from lee.schermerhorn@xxxxxx are
numa-generic-management-of-nodemasks-for-various-purposes.patch
memoryless-nodes-introduce-mask-of-nodes-with-memory.patch
memoryless-nodes-fix-interleave-behavior.patch
oom-use-the-n_memory-map-instead-of-constructing-one-on-the-fly.patch
memoryless-nodes-no-need-for-kswapd.patch
memoryless-node-slab-support.patch
memoryless-nodes-slub-support.patch
uncached-allocator-handle-memoryless-nodes.patch
memoryless-node-allow-profiling-data-to-fall-back-to-other-nodes.patch
memoryless-nodes-update-memory-policy-and-page-migration.patch
add-n_cpu-node-state.patch
memoryless-nodes-fix-gfp_thisnode-behavior.patch
memoryless-nodes-use-node_memory_map-for-cpusets.patch
memoryless-nodes-drop-one-memoryless-node-boot-warning.patch
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