* [PATCH v2 0/6] numabalancing patches
@ 2018-09-21 17:48 Srikar Dronamraju
2018-09-21 17:48 ` [PATCH v2 1/6] sched/numa: Stop multiple tasks from moving to the CPU at the same time Srikar Dronamraju
` (5 more replies)
0 siblings, 6 replies; 13+ messages in thread
From: Srikar Dronamraju @ 2018-09-21 17:48 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra
Cc: LKML, Mel Gorman, Rik van Riel, Srikar Dronamraju,
Thomas Gleixner, Jirka Hladky
This patchset provides left out patches from the previous series.
http://lore.kernel.org/lkml/1529514181-9842-1-git-send-email-srikar@linux.vnet.ibm.com
Changes from previous posting:
Rebased the patchset to 4.19-rc4.
Handled comments from Ingo Molnar,Peter Peter Zijlstra and Mel Gorman.
Reorder to keep the most discussed patches at the end.
Some of the Ack/Reviewed-by carried from
http://lore.kernel.org/lkml/1528106428-19992-1-git-send-email-srikar@linux.vnet.ibm.com
Please refer to previous postings
http://lore.kernel.org/lkml/1533276841-16341-1-git-send-email-srikar@linux.vnet.ibm.com
http://lore.kernel.org/lkml/1529514181-9842-1-git-send-email-srikar@linux.vnet.ibm.com
http://lore.kernel.org/lkml/1528106428-19992-1-git-send-email-srikar@linux.vnet.ibm.com
Specjbb2005 results (8 warehouses)
Higher bops are better
2 Socket - 2 Node Haswell - X86
JVMS Prev Current %Change
4 200194 205910 2.85523
1 311331 318491 2.2998
2 Socket - 4 Node Power8 - PowerNV
JVMS Prev Current %Change
1 197654 226796 14.7439
4 Socket - 4 Node Power7 - PowerVM
JVMS Prev Current %Change
8 52227.1 60370 15.5913
1 102529 108100 5.43358
Mel Gorman (1):
sched/numa: Limit the conditions where scan period is reset
Srikar Dronamraju (5):
sched/numa: Stop multiple tasks from moving to the CPU at the same
time
sched/numa: Pass destination CPU as a parameter to migrate_task_rq
sched/numa: Reset scan rate whenever task moves across nodes
mm/migrate: Use trylock while resetting rate limit
sched/numa: Avoid task migration for small NUMA improvement
kernel/sched/core.c | 2 +-
kernel/sched/deadline.c | 2 +-
kernel/sched/fair.c | 92 ++++++++++++++++++++++++++++++++++++++++++-------
kernel/sched/sched.h | 3 +-
mm/migrate.c | 16 ++++++---
5 files changed, 96 insertions(+), 19 deletions(-)
--
2.7.4
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v2 1/6] sched/numa: Stop multiple tasks from moving to the CPU at the same time
2018-09-21 17:48 [PATCH v2 0/6] numabalancing patches Srikar Dronamraju
@ 2018-09-21 17:48 ` Srikar Dronamraju
2018-10-02 10:03 ` [tip:sched/core] " tip-bot for Srikar Dronamraju
2018-09-21 17:48 ` [PATCH v2 2/6] sched/numa: Pass destination CPU as a parameter to migrate_task_rq Srikar Dronamraju
` (4 subsequent siblings)
5 siblings, 1 reply; 13+ messages in thread
From: Srikar Dronamraju @ 2018-09-21 17:48 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra
Cc: LKML, Mel Gorman, Rik van Riel, Srikar Dronamraju,
Thomas Gleixner, Jirka Hladky
Task migration under NUMA balancing can happen in parallel. More than
one task might choose to migrate to the same CPU at the same time. This
can result in
- During task swap, choosing a task that was not part of the evaluation.
- During task swap, task which just got moved into its preferred node,
moving to a completely different node.
- During task swap, task failing to move to the preferred node, will have
to wait an extra interval for the next migrate opportunity.
- During task movement, multiple task movements can cause load imbalance.
This problem is more likely if there are more cores per node or more
nodes in the system.
Use a per run-queue variable to check if NUMA-balance is active on the
run-queue.
Specjbb2005 results (8 warehouses)
Higher bops are better
2 Socket - 2 Node Haswell - X86
JVMS Prev Current %Change
4 200194 203353 1.57797
1 311331 328205 5.41995
2 Socket - 4 Node Power8 - PowerNV
JVMS Prev Current %Change
1 197654 214384 8.46429
2 Socket - 2 Node Power9 - PowerNV
JVMS Prev Current %Change
4 192605 188553 -2.10379
1 213402 196273 -8.02664
4 Socket - 4 Node Power7 - PowerVM
JVMS Prev Current %Change
8 52227.1 57581.2 10.2516
1 102529 103468 0.915838
There is a regression on power 9 box. If we look at the details,
that box has a sudden jump in cache-misses with this patch.
All other parameters seem to be pointing towards NUMA
consolidation.
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 13,345,784 13,941,377
migrations 1,127,820 1,157,323
faults 374,736 382,175
cache-misses 55,132,054,603 54,993,823,500
sched:sched_move_numa 1,923 2,005
sched:sched_stick_numa 52 14
sched:sched_swap_numa 595 529
migrate:mm_migrate_pages 1,932 1,573
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 60605 67099
numa_hint_faults_local 51804 58456
numa_hit 239945 240416
numa_huge_pte_updates 14 18
numa_interleave 60 65
numa_local 239865 240339
numa_other 80 77
numa_pages_migrated 1931 1574
numa_pte_updates 67823 77182
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 3,016,467 3,176,453
migrations 37,326 30,238
faults 115,342 87,869
cache-misses 11,692,155,554 12,544,479,391
sched:sched_move_numa 965 23
sched:sched_stick_numa 8 0
sched:sched_swap_numa 35 6
migrate:mm_migrate_pages 1,168 10
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 16286 236
numa_hint_faults_local 11863 201
numa_hit 112482 72293
numa_huge_pte_updates 33 0
numa_interleave 20 26
numa_local 112419 72233
numa_other 63 60
numa_pages_migrated 1144 8
numa_pte_updates 32859 0
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 8,629,724 8,478,820
migrations 221,052 171,323
faults 308,661 307,499
cache-misses 135,574,913 240,353,599
sched:sched_move_numa 147 214
sched:sched_stick_numa 0 0
sched:sched_swap_numa 2 4
migrate:mm_migrate_pages 64 89
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 11481 5301
numa_hint_faults_local 10968 4745
numa_hit 89773 92943
numa_huge_pte_updates 0 0
numa_interleave 1116 899
numa_local 89220 92345
numa_other 553 598
numa_pages_migrated 62 88
numa_pte_updates 11694 5505
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 2,272,887 2,066,172
migrations 12,206 11,076
faults 163,704 149,544
cache-misses 4,801,186 10,398,067
sched:sched_move_numa 44 43
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 0
migrate:mm_migrate_pages 17 6
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 2261 3552
numa_hint_faults_local 1993 3347
numa_hit 25726 25611
numa_huge_pte_updates 0 0
numa_interleave 239 213
numa_local 25498 25583
numa_other 228 28
numa_pages_migrated 17 6
numa_pte_updates 2266 3535
perf stats 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 117,980,962 99,358,136
migrations 3,950,220 4,041,607
faults 736,979 749,653
cache-misses 224,976,072,879 225,562,543,251
sched:sched_move_numa 504 771
sched:sched_stick_numa 50 14
sched:sched_swap_numa 239 204
migrate:mm_migrate_pages 1,260 1,180
vmstat 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 18293 27409
numa_hint_faults_local 11969 20677
numa_hit 240854 239988
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 240851 239983
numa_other 3 5
numa_pages_migrated 1190 1016
numa_pte_updates 18106 27916
perf stats 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 61,053,158 60,899,307
migrations 551,586 544,668
faults 244,174 270,834
cache-misses 74,326,766,973 74,543,455,635
sched:sched_move_numa 344 735
sched:sched_stick_numa 24 25
sched:sched_swap_numa 140 174
migrate:mm_migrate_pages 568 816
vmstat 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 6461 11059
numa_hint_faults_local 2283 4733
numa_hit 35661 41384
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 35661 41383
numa_other 0 1
numa_pages_migrated 568 815
numa_pte_updates 6518 11323
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog
Add comments as requested by Peter.
Changelog v1->v2:
Rename cpu to CPU
Rename numa to NUMA
kernel/sched/fair.c | 22 ++++++++++++++++++++++
kernel/sched/sched.h | 1 +
2 files changed, 23 insertions(+)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index f808ddf..3b0b75d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1514,6 +1514,21 @@ struct task_numa_env {
static void task_numa_assign(struct task_numa_env *env,
struct task_struct *p, long imp)
{
+ struct rq *rq = cpu_rq(env->dst_cpu);
+
+ /* Bail out if run-queue part of active NUMA balance. */
+ if (xchg(&rq->numa_migrate_on, 1))
+ return;
+
+ /*
+ * Clear previous best_cpu/rq numa-migrate flag, since task now
+ * found a better CPU to move/swap.
+ */
+ if (env->best_cpu != -1) {
+ rq = cpu_rq(env->best_cpu);
+ WRITE_ONCE(rq->numa_migrate_on, 0);
+ }
+
if (env->best_task)
put_task_struct(env->best_task);
if (p)
@@ -1569,6 +1584,9 @@ static void task_numa_compare(struct task_numa_env *env,
long moveimp = imp;
int dist = env->dist;
+ if (READ_ONCE(dst_rq->numa_migrate_on))
+ return;
+
rcu_read_lock();
cur = task_rcu_dereference(&dst_rq->curr);
if (cur && ((cur->flags & PF_EXITING) || is_idle_task(cur)))
@@ -1710,6 +1728,7 @@ static int task_numa_migrate(struct task_struct *p)
.best_cpu = -1,
};
struct sched_domain *sd;
+ struct rq *best_rq;
unsigned long taskweight, groupweight;
int nid, ret, dist;
long taskimp, groupimp;
@@ -1811,14 +1830,17 @@ static int task_numa_migrate(struct task_struct *p)
*/
p->numa_scan_period = task_scan_start(p);
+ best_rq = cpu_rq(env.best_cpu);
if (env.best_task == NULL) {
ret = migrate_task_to(p, env.best_cpu);
+ WRITE_ONCE(best_rq->numa_migrate_on, 0);
if (ret != 0)
trace_sched_stick_numa(p, env.src_cpu, env.best_cpu);
return ret;
}
ret = migrate_swap(p, env.best_task, env.best_cpu, env.src_cpu);
+ WRITE_ONCE(best_rq->numa_migrate_on, 0);
if (ret != 0)
trace_sched_stick_numa(p, env.src_cpu, task_cpu(env.best_task));
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 4a2e8ca..0b91612 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -783,6 +783,7 @@ struct rq {
#ifdef CONFIG_NUMA_BALANCING
unsigned int nr_numa_running;
unsigned int nr_preferred_running;
+ unsigned int numa_migrate_on;
#endif
#define CPU_LOAD_IDX_MAX 5
unsigned long cpu_load[CPU_LOAD_IDX_MAX];
--
2.7.4
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH v2 2/6] sched/numa: Pass destination CPU as a parameter to migrate_task_rq
2018-09-21 17:48 [PATCH v2 0/6] numabalancing patches Srikar Dronamraju
2018-09-21 17:48 ` [PATCH v2 1/6] sched/numa: Stop multiple tasks from moving to the CPU at the same time Srikar Dronamraju
@ 2018-09-21 17:48 ` Srikar Dronamraju
2018-10-02 10:03 ` [tip:sched/core] " tip-bot for Srikar Dronamraju
2018-09-21 17:48 ` [PATCH v2 3/6] sched/numa: Reset scan rate whenever task moves across nodes Srikar Dronamraju
` (3 subsequent siblings)
5 siblings, 1 reply; 13+ messages in thread
From: Srikar Dronamraju @ 2018-09-21 17:48 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra
Cc: LKML, Mel Gorman, Rik van Riel, Srikar Dronamraju,
Thomas Gleixner, Jirka Hladky
This additional parameter (new_cpu) is used later for identifying if
task migration is across nodes.
No functional change.
Specjbb2005 results (8 warehouses)
Higher bops are better
2 Socket - 2 Node Haswell - X86
JVMS Prev Current %Change
4 203353 200668 -1.32036
1 328205 321791 -1.95427
2 Socket - 4 Node Power8 - PowerNV
JVMS Prev Current %Change
1 214384 204848 -4.44809
2 Socket - 2 Node Power9 - PowerNV
JVMS Prev Current %Change
4 188553 188098 -0.241311
1 196273 200351 2.07772
4 Socket - 4 Node Power7 - PowerVM
JVMS Prev Current %Change
8 57581.2 58145.9 0.980702
1 103468 103798 0.318939
Brings out the variance between different specjbb2005 runs.
Some events stats before and after applying the patch.
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 13,941,377 13,912,183
migrations 1,157,323 1,155,931
faults 382,175 367,139
cache-misses 54,993,823,500 54,240,196,814
sched:sched_move_numa 2,005 1,571
sched:sched_stick_numa 14 9
sched:sched_swap_numa 529 463
migrate:mm_migrate_pages 1,573 703
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 67099 50155
numa_hint_faults_local 58456 45264
numa_hit 240416 239652
numa_huge_pte_updates 18 36
numa_interleave 65 68
numa_local 240339 239576
numa_other 77 76
numa_pages_migrated 1574 680
numa_pte_updates 77182 71146
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 3,176,453 3,156,720
migrations 30,238 30,354
faults 87,869 97,261
cache-misses 12,544,479,391 12,400,026,826
sched:sched_move_numa 23 4
sched:sched_stick_numa 0 0
sched:sched_swap_numa 6 1
migrate:mm_migrate_pages 10 20
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 236 272
numa_hint_faults_local 201 186
numa_hit 72293 71362
numa_huge_pte_updates 0 0
numa_interleave 26 23
numa_local 72233 71299
numa_other 60 63
numa_pages_migrated 8 2
numa_pte_updates 0 0
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 8,478,820 8,606,824
migrations 171,323 155,352
faults 307,499 301,409
cache-misses 240,353,599 157,759,224
sched:sched_move_numa 214 168
sched:sched_stick_numa 0 0
sched:sched_swap_numa 4 3
migrate:mm_migrate_pages 89 125
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 5301 4650
numa_hint_faults_local 4745 3946
numa_hit 92943 90489
numa_huge_pte_updates 0 0
numa_interleave 899 892
numa_local 92345 90034
numa_other 598 455
numa_pages_migrated 88 124
numa_pte_updates 5505 4818
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 2,066,172 2,113,167
migrations 11,076 10,533
faults 149,544 142,727
cache-misses 10,398,067 5,594,192
sched:sched_move_numa 43 10
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 0
migrate:mm_migrate_pages 6 6
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 3552 744
numa_hint_faults_local 3347 584
numa_hit 25611 25551
numa_huge_pte_updates 0 0
numa_interleave 213 263
numa_local 25583 25302
numa_other 28 249
numa_pages_migrated 6 6
numa_pte_updates 3535 744
perf stats 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 99,358,136 101,227,352
migrations 4,041,607 4,151,829
faults 749,653 745,233
cache-misses 225,562,543,251 224,669,561,766
sched:sched_move_numa 771 617
sched:sched_stick_numa 14 2
sched:sched_swap_numa 204 187
migrate:mm_migrate_pages 1,180 316
vmstat 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 27409 24195
numa_hint_faults_local 20677 21639
numa_hit 239988 238331
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 239983 238331
numa_other 5 0
numa_pages_migrated 1016 204
numa_pte_updates 27916 24561
perf stats 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 60,899,307 62,738,978
migrations 544,668 562,702
faults 270,834 228,465
cache-misses 74,543,455,635 75,778,067,952
sched:sched_move_numa 735 648
sched:sched_stick_numa 25 13
sched:sched_swap_numa 174 137
migrate:mm_migrate_pages 816 733
vmstat 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 11059 10281
numa_hint_faults_local 4733 3242
numa_hit 41384 36338
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 41383 36338
numa_other 1 0
numa_pages_migrated 815 706
numa_pte_updates 11323 10176
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v1->v2:
Rename cpu to CPU
Rename numa to NUMA
kernel/sched/core.c | 2 +-
kernel/sched/deadline.c | 2 +-
kernel/sched/fair.c | 2 +-
kernel/sched/sched.h | 2 +-
4 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 625bc98..ad97f3b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1167,7 +1167,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
if (task_cpu(p) != new_cpu) {
if (p->sched_class->migrate_task_rq)
- p->sched_class->migrate_task_rq(p);
+ p->sched_class->migrate_task_rq(p, new_cpu);
p->se.nr_migrations++;
rseq_migrate(p);
perf_event_task_migrate(p);
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 997ea7b..91e4202 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1607,7 +1607,7 @@ select_task_rq_dl(struct task_struct *p, int cpu, int sd_flag, int flags)
return cpu;
}
-static void migrate_task_rq_dl(struct task_struct *p)
+static void migrate_task_rq_dl(struct task_struct *p, int new_cpu __maybe_unused)
{
struct rq *rq;
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 3b0b75d..bc768156 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6297,7 +6297,7 @@ static void detach_entity_cfs_rq(struct sched_entity *se);
* cfs_rq_of(p) references at time of call are still valid and identify the
* previous CPU. The caller guarantees p->pi_lock or task_rq(p)->lock is held.
*/
-static void migrate_task_rq_fair(struct task_struct *p)
+static void migrate_task_rq_fair(struct task_struct *p, int new_cpu __maybe_unused)
{
/*
* As blocked tasks retain absolute vruntime the migration needs to
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 0b91612..455fa33 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1524,7 +1524,7 @@ struct sched_class {
#ifdef CONFIG_SMP
int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
- void (*migrate_task_rq)(struct task_struct *p);
+ void (*migrate_task_rq)(struct task_struct *p, int new_cpu);
void (*task_woken)(struct rq *this_rq, struct task_struct *task);
--
2.7.4
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH v2 3/6] sched/numa: Reset scan rate whenever task moves across nodes
2018-09-21 17:48 [PATCH v2 0/6] numabalancing patches Srikar Dronamraju
2018-09-21 17:48 ` [PATCH v2 1/6] sched/numa: Stop multiple tasks from moving to the CPU at the same time Srikar Dronamraju
2018-09-21 17:48 ` [PATCH v2 2/6] sched/numa: Pass destination CPU as a parameter to migrate_task_rq Srikar Dronamraju
@ 2018-09-21 17:48 ` Srikar Dronamraju
2018-10-02 10:04 ` [tip:sched/core] " tip-bot for Srikar Dronamraju
2018-09-21 17:48 ` [PATCH v2 4/6] sched/numa: Limit the conditions where scan period is reset Srikar Dronamraju
` (2 subsequent siblings)
5 siblings, 1 reply; 13+ messages in thread
From: Srikar Dronamraju @ 2018-09-21 17:48 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra
Cc: LKML, Mel Gorman, Rik van Riel, Srikar Dronamraju,
Thomas Gleixner, Jirka Hladky
Currently task scan rate is reset when NUMA balancer migrates the task
to a different node. If NUMA balancer initiates a swap, reset is only
applicable to the task that initiates the swap. Similarly no scan rate
reset is done if the task is migrated across nodes by traditional load
balancer.
Instead move the scan reset to the migrate_task_rq. This ensures the
task moved out of its preferred node, either gets back to its preferred
node quickly or finds a new preferred node. Doing so, would be fair to
all tasks migrating across nodes.
Specjbb2005 results (8 warehouses)
Higher bops are better
2 Socket - 2 Node Haswell - X86
JVMS Prev Current %Change
4 200668 203370 1.3465
1 321791 328431 2.06345
2 Socket - 4 Node Power8 - PowerNV
JVMS Prev Current %Change
1 204848 206070 0.59654
2 Socket - 2 Node Power9 - PowerNV
JVMS Prev Current %Change
4 188098 188386 0.153112
1 200351 201566 0.606436
4 Socket - 4 Node Power7 - PowerVM
JVMS Prev Current %Change
8 58145.9 59157.4 1.73959
1 103798 105495 1.63491
Some events stats before and after applying the patch.
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 13,912,183 13,825,492
migrations 1,155,931 1,152,509
faults 367,139 371,948
cache-misses 54,240,196,814 55,654,206,041
sched:sched_move_numa 1,571 1,856
sched:sched_stick_numa 9 4
sched:sched_swap_numa 463 428
migrate:mm_migrate_pages 703 898
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 50155 57146
numa_hint_faults_local 45264 51612
numa_hit 239652 238164
numa_huge_pte_updates 36 16
numa_interleave 68 63
numa_local 239576 238085
numa_other 76 79
numa_pages_migrated 680 883
numa_pte_updates 71146 67540
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 3,156,720 3,288,525
migrations 30,354 38,652
faults 97,261 111,678
cache-misses 12,400,026,826 12,111,197,376
sched:sched_move_numa 4 900
sched:sched_stick_numa 0 0
sched:sched_swap_numa 1 5
migrate:mm_migrate_pages 20 714
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 272 18572
numa_hint_faults_local 186 14850
numa_hit 71362 73197
numa_huge_pte_updates 0 11
numa_interleave 23 25
numa_local 71299 73138
numa_other 63 59
numa_pages_migrated 2 712
numa_pte_updates 0 24021
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 8,606,824 8,451,543
migrations 155,352 202,804
faults 301,409 310,024
cache-misses 157,759,224 253,522,507
sched:sched_move_numa 168 213
sched:sched_stick_numa 0 0
sched:sched_swap_numa 3 2
migrate:mm_migrate_pages 125 88
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 4650 11830
numa_hint_faults_local 3946 11301
numa_hit 90489 90038
numa_huge_pte_updates 0 0
numa_interleave 892 855
numa_local 90034 89796
numa_other 455 242
numa_pages_migrated 124 88
numa_pte_updates 4818 12039
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 2,113,167 2,049,153
migrations 10,533 11,405
faults 142,727 162,309
cache-misses 5,594,192 7,203,343
sched:sched_move_numa 10 22
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 0
migrate:mm_migrate_pages 6 1
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 744 1693
numa_hint_faults_local 584 1669
numa_hit 25551 25177
numa_huge_pte_updates 0 0
numa_interleave 263 194
numa_local 25302 24993
numa_other 249 184
numa_pages_migrated 6 1
numa_pte_updates 744 1577
perf stats 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 101,227,352 94,515,937
migrations 4,151,829 4,203,554
faults 745,233 832,697
cache-misses 224,669,561,766 226,248,698,331
sched:sched_move_numa 617 1,730
sched:sched_stick_numa 2 14
sched:sched_swap_numa 187 432
migrate:mm_migrate_pages 316 1,398
vmstat 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 24195 80079
numa_hint_faults_local 21639 68620
numa_hit 238331 241187
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 238331 241186
numa_other 0 1
numa_pages_migrated 204 1347
numa_pte_updates 24561 80729
perf stats 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 62,738,978 63,704,961
migrations 562,702 573,404
faults 228,465 230,878
cache-misses 75,778,067,952 76,568,222,781
sched:sched_move_numa 648 509
sched:sched_stick_numa 13 31
sched:sched_swap_numa 137 182
migrate:mm_migrate_pages 733 541
vmstat 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 10281 8501
numa_hint_faults_local 3242 2960
numa_hit 36338 35526
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 36338 35526
numa_other 0 0
numa_pages_migrated 706 539
numa_pte_updates 10176 8433
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v1->v2:
Rename cpu to CPU
Rename numa to NUMA
kernel/sched/fair.c | 26 +++++++++++++++++++-------
1 file changed, 19 insertions(+), 7 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index bc768156..5cbfb30 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1824,12 +1824,6 @@ static int task_numa_migrate(struct task_struct *p)
if (env.best_cpu == -1)
return -EAGAIN;
- /*
- * Reset the scan period if the task is being rescheduled on an
- * alternative node to recheck if the tasks is now properly placed.
- */
- p->numa_scan_period = task_scan_start(p);
-
best_rq = cpu_rq(env.best_cpu);
if (env.best_task == NULL) {
ret = migrate_task_to(p, env.best_cpu);
@@ -2618,6 +2612,18 @@ void task_tick_numa(struct rq *rq, struct task_struct *curr)
}
}
+static void update_scan_period(struct task_struct *p, int new_cpu)
+{
+ int src_nid = cpu_to_node(task_cpu(p));
+ int dst_nid = cpu_to_node(new_cpu);
+
+ if (!p->mm || !p->numa_faults || (p->flags & PF_EXITING))
+ return;
+
+ if (src_nid != dst_nid)
+ p->numa_scan_period = task_scan_start(p);
+}
+
#else
static void task_tick_numa(struct rq *rq, struct task_struct *curr)
{
@@ -2631,6 +2637,10 @@ static inline void account_numa_dequeue(struct rq *rq, struct task_struct *p)
{
}
+static inline void update_scan_period(struct task_struct *p, int new_cpu)
+{
+}
+
#endif /* CONFIG_NUMA_BALANCING */
static void
@@ -6297,7 +6307,7 @@ static void detach_entity_cfs_rq(struct sched_entity *se);
* cfs_rq_of(p) references at time of call are still valid and identify the
* previous CPU. The caller guarantees p->pi_lock or task_rq(p)->lock is held.
*/
-static void migrate_task_rq_fair(struct task_struct *p, int new_cpu __maybe_unused)
+static void migrate_task_rq_fair(struct task_struct *p, int new_cpu)
{
/*
* As blocked tasks retain absolute vruntime the migration needs to
@@ -6350,6 +6360,8 @@ static void migrate_task_rq_fair(struct task_struct *p, int new_cpu __maybe_unus
/* We have migrated, no longer consider this task hot */
p->se.exec_start = 0;
+
+ update_scan_period(p, new_cpu);
}
static void task_dead_fair(struct task_struct *p)
--
2.7.4
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH v2 4/6] sched/numa: Limit the conditions where scan period is reset
2018-09-21 17:48 [PATCH v2 0/6] numabalancing patches Srikar Dronamraju
` (2 preceding siblings ...)
2018-09-21 17:48 ` [PATCH v2 3/6] sched/numa: Reset scan rate whenever task moves across nodes Srikar Dronamraju
@ 2018-09-21 17:48 ` Srikar Dronamraju
2018-10-02 10:04 ` [tip:sched/core] " tip-bot for Mel Gorman
2018-09-21 17:49 ` [PATCH v2 5/6] mm/migrate: Use trylock while resetting rate limit Srikar Dronamraju
2018-09-21 17:49 ` [PATCH v2 6/6] sched/numa: Avoid task migration for small NUMA improvement Srikar Dronamraju
5 siblings, 1 reply; 13+ messages in thread
From: Srikar Dronamraju @ 2018-09-21 17:48 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra
Cc: LKML, Mel Gorman, Rik van Riel, Srikar Dronamraju,
Thomas Gleixner, Jirka Hladky
From: Mel Gorman <mgorman@techsingularity.net>
migrate_task_rq_fair resets the scan rate for NUMA balancing on every
cross-node migration. In the event of excessive load balancing due to
saturation, this may result in the scan rate being pegged at maximum and
further overloading the machine.
This patch only resets the scan if NUMA balancing is active, a preferred
node has been selected and the task is being migrated from the preferred
node as these are the most harmful. For example, a migration to the preferred
node does not justify a faster scan rate. Similarly, a migration between two
nodes that are not preferred is probably bouncing due to over-saturation of
the machine. In that case, scanning faster and trapping more NUMA faults
will further overload the machine.
Specjbb2005 results (8 warehouses)
Higher bops are better
2 Socket - 2 Node Haswell - X86
JVMS Prev Current %Change
4 203370 205332 0.964744
1 328431 319785 -2.63252
2 Socket - 4 Node Power8 - PowerNV
JVMS Prev Current %Change
1 206070 206585 0.249915
2 Socket - 2 Node Power9 - PowerNV
JVMS Prev Current %Change
4 188386 189162 0.41192
1 201566 213760 6.04963
4 Socket - 4 Node Power7 - PowerVM
JVMS Prev Current %Change
8 59157.4 58736.8 -0.710985
1 105495 105419 -0.0720413
Some events stats before and after applying the patch.
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 13,825,492 14,285,708
migrations 1,152,509 1,180,621
faults 371,948 339,114
cache-misses 55,654,206,041 55,205,631,894
sched:sched_move_numa 1,856 843
sched:sched_stick_numa 4 6
sched:sched_swap_numa 428 219
migrate:mm_migrate_pages 898 365
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 57146 26907
numa_hint_faults_local 51612 24279
numa_hit 238164 239771
numa_huge_pte_updates 16 0
numa_interleave 63 68
numa_local 238085 239688
numa_other 79 83
numa_pages_migrated 883 363
numa_pte_updates 67540 27415
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 3,288,525 3,202,779
migrations 38,652 37,186
faults 111,678 106,076
cache-misses 12,111,197,376 12,024,873,744
sched:sched_move_numa 900 931
sched:sched_stick_numa 0 0
sched:sched_swap_numa 5 1
migrate:mm_migrate_pages 714 637
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 18572 17409
numa_hint_faults_local 14850 14367
numa_hit 73197 73953
numa_huge_pte_updates 11 20
numa_interleave 25 25
numa_local 73138 73892
numa_other 59 61
numa_pages_migrated 712 668
numa_pte_updates 24021 27276
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 8,451,543 8,474,013
migrations 202,804 254,934
faults 310,024 320,506
cache-misses 253,522,507 110,580,458
sched:sched_move_numa 213 725
sched:sched_stick_numa 0 0
sched:sched_swap_numa 2 7
migrate:mm_migrate_pages 88 145
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 11830 22797
numa_hint_faults_local 11301 21539
numa_hit 90038 89308
numa_huge_pte_updates 0 0
numa_interleave 855 865
numa_local 89796 88955
numa_other 242 353
numa_pages_migrated 88 149
numa_pte_updates 12039 22930
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 2,049,153 2,195,628
migrations 11,405 11,179
faults 162,309 149,656
cache-misses 7,203,343 8,117,515
sched:sched_move_numa 22 49
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 0
migrate:mm_migrate_pages 1 5
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 1693 3577
numa_hint_faults_local 1669 3476
numa_hit 25177 26142
numa_huge_pte_updates 0 0
numa_interleave 194 358
numa_local 24993 26042
numa_other 184 100
numa_pages_migrated 1 5
numa_pte_updates 1577 3587
perf stats 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 94,515,937 100,602,296
migrations 4,203,554 4,135,630
faults 832,697 789,256
cache-misses 226,248,698,331 226,160,621,058
sched:sched_move_numa 1,730 1,366
sched:sched_stick_numa 14 16
sched:sched_swap_numa 432 374
migrate:mm_migrate_pages 1,398 1,350
vmstat 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 80079 47857
numa_hint_faults_local 68620 39768
numa_hit 241187 240165
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 241186 240165
numa_other 1 0
numa_pages_migrated 1347 1224
numa_pte_updates 80729 48354
perf stats 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 63,704,961 58,515,496
migrations 573,404 564,845
faults 230,878 245,807
cache-misses 76,568,222,781 73,603,757,976
sched:sched_move_numa 509 996
sched:sched_stick_numa 31 10
sched:sched_swap_numa 182 193
migrate:mm_migrate_pages 541 646
vmstat 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 8501 13422
numa_hint_faults_local 2960 5619
numa_hit 35526 36118
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 35526 36116
numa_other 0 2
numa_pages_migrated 539 616
numa_pte_updates 8433 13374
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v1->v2:
Rename numa to NUMA
kernel/sched/fair.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 5cbfb30..3529bf6 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2617,11 +2617,32 @@ static void update_scan_period(struct task_struct *p, int new_cpu)
int src_nid = cpu_to_node(task_cpu(p));
int dst_nid = cpu_to_node(new_cpu);
+ if (!static_branch_likely(&sched_numa_balancing))
+ return;
+
if (!p->mm || !p->numa_faults || (p->flags & PF_EXITING))
return;
- if (src_nid != dst_nid)
- p->numa_scan_period = task_scan_start(p);
+ if (src_nid == dst_nid)
+ return;
+
+ /*
+ * Allow resets if faults have been trapped before one scan
+ * has completed. This is most likely due to a new task that
+ * is pulled cross-node due to wakeups or load balancing.
+ */
+ if (p->numa_scan_seq) {
+ /*
+ * Avoid scan adjustments if moving to the preferred
+ * node or if the task was not previously running on
+ * the preferred node.
+ */
+ if (dst_nid == p->numa_preferred_nid ||
+ (p->numa_preferred_nid != -1 && src_nid != p->numa_preferred_nid))
+ return;
+ }
+
+ p->numa_scan_period = task_scan_start(p);
}
#else
--
2.7.4
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH v2 5/6] mm/migrate: Use trylock while resetting rate limit
2018-09-21 17:48 [PATCH v2 0/6] numabalancing patches Srikar Dronamraju
` (3 preceding siblings ...)
2018-09-21 17:48 ` [PATCH v2 4/6] sched/numa: Limit the conditions where scan period is reset Srikar Dronamraju
@ 2018-09-21 17:49 ` Srikar Dronamraju
2018-10-02 10:05 ` [tip:sched/core] mm/migrate: Use spin_trylock() " tip-bot for Srikar Dronamraju
2018-09-21 17:49 ` [PATCH v2 6/6] sched/numa: Avoid task migration for small NUMA improvement Srikar Dronamraju
5 siblings, 1 reply; 13+ messages in thread
From: Srikar Dronamraju @ 2018-09-21 17:49 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra
Cc: LKML, Mel Gorman, Rik van Riel, Srikar Dronamraju,
Thomas Gleixner, Jirka Hladky
Since this spinlock will only serialize the migrate rate limiting,
convert the spinlock to a trylock. If another thread is updating, this
task can move on.
Specjbb2005 results (8 warehouses)
Higher bops are better
2 Socket - 2 Node Haswell - X86
JVMS Prev Current %Change
4 205332 198512 -3.32145
1 319785 313559 -1.94693
2 Socket - 4 Node Power8 - PowerNV
JVMS Prev Current %Change
8 74912 74761.9 -0.200368
1 206585 214874 4.01239
2 Socket - 2 Node Power9 - PowerNV
JVMS Prev Current %Change
4 189162 180536 -4.56011
1 213760 210281 -1.62753
4 Socket - 4 Node Power7 - PowerVM
JVMS Prev Current %Change
8 58736.8 56511.4 -3.78877
1 105419 104899 -0.49327
Avoiding stretching of window intervals may be the reason for the
regression. Also code now uses READ_ONCE/WRITE_ONCE. That may
also be hurting performance to some extent.
Some events stats before and after applying the patch.
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 14,285,708 13,818,546
migrations 1,180,621 1,149,960
faults 339,114 385,583
cache-misses 55,205,631,894 55,259,546,768
sched:sched_move_numa 843 2,257
sched:sched_stick_numa 6 9
sched:sched_swap_numa 219 512
migrate:mm_migrate_pages 365 2,225
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 26907 72692
numa_hint_faults_local 24279 62270
numa_hit 239771 238762
numa_huge_pte_updates 0 48
numa_interleave 68 75
numa_local 239688 238676
numa_other 83 86
numa_pages_migrated 363 2225
numa_pte_updates 27415 98557
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 3,202,779 3,173,490
migrations 37,186 36,966
faults 106,076 108,776
cache-misses 12,024,873,744 12,200,075,320
sched:sched_move_numa 931 1,264
sched:sched_stick_numa 0 0
sched:sched_swap_numa 1 0
migrate:mm_migrate_pages 637 899
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 17409 21109
numa_hint_faults_local 14367 17120
numa_hit 73953 72934
numa_huge_pte_updates 20 42
numa_interleave 25 33
numa_local 73892 72866
numa_other 61 68
numa_pages_migrated 668 915
numa_pte_updates 27276 42326
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 8,474,013 8,312,022
migrations 254,934 231,705
faults 320,506 310,242
cache-misses 110,580,458 402,324,573
sched:sched_move_numa 725 193
sched:sched_stick_numa 0 0
sched:sched_swap_numa 7 3
migrate:mm_migrate_pages 145 93
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 22797 11838
numa_hint_faults_local 21539 11216
numa_hit 89308 90689
numa_huge_pte_updates 0 0
numa_interleave 865 1579
numa_local 88955 89634
numa_other 353 1055
numa_pages_migrated 149 92
numa_pte_updates 22930 12109
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 2,195,628 2,170,481
migrations 11,179 10,126
faults 149,656 160,962
cache-misses 8,117,515 10,834,845
sched:sched_move_numa 49 10
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 0
migrate:mm_migrate_pages 5 2
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 3577 403
numa_hint_faults_local 3476 358
numa_hit 26142 25898
numa_huge_pte_updates 0 0
numa_interleave 358 207
numa_local 26042 25860
numa_other 100 38
numa_pages_migrated 5 2
numa_pte_updates 3587 400
perf stats 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 100,602,296 110,339,633
migrations 4,135,630 4,139,812
faults 789,256 863,622
cache-misses 226,160,621,058 231,838,045,660
sched:sched_move_numa 1,366 2,196
sched:sched_stick_numa 16 33
sched:sched_swap_numa 374 544
migrate:mm_migrate_pages 1,350 2,469
vmstat 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 47857 85748
numa_hint_faults_local 39768 66831
numa_hit 240165 242213
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 240165 242211
numa_other 0 2
numa_pages_migrated 1224 2376
numa_pte_updates 48354 86233
perf stats 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 58,515,496 59,331,057
migrations 564,845 552,019
faults 245,807 266,586
cache-misses 73,603,757,976 73,796,312,990
sched:sched_move_numa 996 981
sched:sched_stick_numa 10 54
sched:sched_swap_numa 193 286
migrate:mm_migrate_pages 646 713
vmstat 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 13422 14807
numa_hint_faults_local 5619 5738
numa_hit 36118 36230
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 36116 36228
numa_other 2 2
numa_pages_migrated 616 703
numa_pte_updates 13374 14742
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
---
Changelog:
Fix stretch every interval pointed by Peter Zijlstra.
mm/migrate.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index d6a2e89..4f1d894 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1867,16 +1867,24 @@ static unsigned int ratelimit_pages __read_mostly = 128 << (20 - PAGE_SHIFT);
static bool numamigrate_update_ratelimit(pg_data_t *pgdat,
unsigned long nr_pages)
{
+ unsigned long next_window, interval;
+
+ next_window = READ_ONCE(pgdat->numabalancing_migrate_next_window);
+ interval = msecs_to_jiffies(migrate_interval_millisecs);
+
/*
* Rate-limit the amount of data that is being migrated to a node.
* Optimal placement is no good if the memory bus is saturated and
* all the time is being spent migrating!
*/
- if (time_after(jiffies, pgdat->numabalancing_migrate_next_window)) {
- spin_lock(&pgdat->numabalancing_migrate_lock);
+ if (time_after(jiffies, next_window) &&
+ spin_trylock(&pgdat->numabalancing_migrate_lock)) {
pgdat->numabalancing_migrate_nr_pages = 0;
- pgdat->numabalancing_migrate_next_window = jiffies +
- msecs_to_jiffies(migrate_interval_millisecs);
+ do {
+ next_window += interval;
+ } while (unlikely(time_after(jiffies, next_window)));
+
+ WRITE_ONCE(pgdat->numabalancing_migrate_next_window, next_window);
spin_unlock(&pgdat->numabalancing_migrate_lock);
}
if (pgdat->numabalancing_migrate_nr_pages > ratelimit_pages) {
--
2.7.4
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH v2 6/6] sched/numa: Avoid task migration for small NUMA improvement
2018-09-21 17:48 [PATCH v2 0/6] numabalancing patches Srikar Dronamraju
` (4 preceding siblings ...)
2018-09-21 17:49 ` [PATCH v2 5/6] mm/migrate: Use trylock while resetting rate limit Srikar Dronamraju
@ 2018-09-21 17:49 ` Srikar Dronamraju
2018-10-02 10:05 ` [tip:sched/core] " tip-bot for Srikar Dronamraju
5 siblings, 1 reply; 13+ messages in thread
From: Srikar Dronamraju @ 2018-09-21 17:49 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra
Cc: LKML, Mel Gorman, Rik van Riel, Srikar Dronamraju,
Thomas Gleixner, Jirka Hladky
If NUMA improvement from the task migration is going to be very
minimal, then avoid task migration.
Specjbb2005 results (8 warehouses)
Higher bops are better
2 Socket - 2 Node Haswell - X86
JVMS Prev Current %Change
4 198512 205910 3.72673
1 313559 318491 1.57291
2 Socket - 4 Node Power8 - PowerNV
JVMS Prev Current %Change
8 74761.9 74935.9 0.232739
1 214874 226796 5.54837
2 Socket - 2 Node Power9 - PowerNV
JVMS Prev Current %Change
4 180536 189780 5.12031
1 210281 205695 -2.18089
4 Socket - 4 Node Power7 - PowerVM
JVMS Prev Current %Change
8 56511.4 60370 6.828
1 104899 108100 3.05151
1/7 cases is regressing, if we look at events migrate_pages seem
to vary the most especially in the regressing case. Also some
amount of variance is expected between different runs of
Specjbb2005.
Some events stats before and after applying the patch.
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 13,818,546 13,801,554
migrations 1,149,960 1,151,541
faults 385,583 433,246
cache-misses 55,259,546,768 55,168,691,835
sched:sched_move_numa 2,257 2,551
sched:sched_stick_numa 9 24
sched:sched_swap_numa 512 904
migrate:mm_migrate_pages 2,225 1,571
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 72692 113682
numa_hint_faults_local 62270 102163
numa_hit 238762 240181
numa_huge_pte_updates 48 36
numa_interleave 75 64
numa_local 238676 240103
numa_other 86 78
numa_pages_migrated 2225 1564
numa_pte_updates 98557 134080
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 3,173,490 3,079,150
migrations 36,966 31,455
faults 108,776 99,081
cache-misses 12,200,075,320 11,588,126,740
sched:sched_move_numa 1,264 1
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 0
migrate:mm_migrate_pages 899 36
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 21109 430
numa_hint_faults_local 17120 77
numa_hit 72934 71277
numa_huge_pte_updates 42 0
numa_interleave 33 22
numa_local 72866 71218
numa_other 68 59
numa_pages_migrated 915 23
numa_pte_updates 42326 0
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 8,312,022 8,707,565
migrations 231,705 171,342
faults 310,242 310,820
cache-misses 402,324,573 136,115,400
sched:sched_move_numa 193 215
sched:sched_stick_numa 0 6
sched:sched_swap_numa 3 24
migrate:mm_migrate_pages 93 162
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 11838 8985
numa_hint_faults_local 11216 8154
numa_hit 90689 93819
numa_huge_pte_updates 0 0
numa_interleave 1579 882
numa_local 89634 93496
numa_other 1055 323
numa_pages_migrated 92 169
numa_pte_updates 12109 9217
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 2,170,481 2,152,072
migrations 10,126 10,704
faults 160,962 164,376
cache-misses 10,834,845 3,818,437
sched:sched_move_numa 10 16
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 7
migrate:mm_migrate_pages 2 199
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 403 2248
numa_hint_faults_local 358 1666
numa_hit 25898 25704
numa_huge_pte_updates 0 0
numa_interleave 207 200
numa_local 25860 25679
numa_other 38 25
numa_pages_migrated 2 197
numa_pte_updates 400 2234
perf stats 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 110,339,633 93,330,595
migrations 4,139,812 4,122,061
faults 863,622 865,979
cache-misses 231,838,045,660 225,395,083,479
sched:sched_move_numa 2,196 2,372
sched:sched_stick_numa 33 24
sched:sched_swap_numa 544 769
migrate:mm_migrate_pages 2,469 1,677
vmstat 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 85748 91638
numa_hint_faults_local 66831 78096
numa_hit 242213 242225
numa_huge_pte_updates 0 0
numa_interleave 0 2
numa_local 242211 242219
numa_other 2 6
numa_pages_migrated 2376 1515
numa_pte_updates 86233 92274
perf stats 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 59,331,057 51,487,271
migrations 552,019 537,170
faults 266,586 256,921
cache-misses 73,796,312,990 70,073,831,187
sched:sched_move_numa 981 576
sched:sched_stick_numa 54 24
sched:sched_swap_numa 286 327
migrate:mm_migrate_pages 713 726
vmstat 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 14807 12000
numa_hint_faults_local 5738 5024
numa_hit 36230 36470
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 36228 36465
numa_other 2 5
numa_pages_migrated 703 726
numa_pte_updates 14742 11930
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v1->v2:
- Handle trivial changes due to variable name change. (Rik Van Riel)
- Drop changes where subsequent better CPU find was rejected for
small NUMA improvement (Rik Van Riel).
Changelog v3->v4:
- Refer cpu -> CPU
- Refer numa -> NUMA
kernel/sched/fair.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 3529bf6..25c7c7e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1568,6 +1568,13 @@ static bool load_too_imbalanced(long src_load, long dst_load,
}
/*
+ * Maximum NUMA importance can be 1998 (2*999);
+ * SMALLIMP @ 30 would be close to 1998/64.
+ * Used to deter task migration.
+ */
+#define SMALLIMP 30
+
+/*
* This checks if the overall compute and NUMA accesses of the system would
* be improved if the source tasks was migrated to the target dst_cpu taking
* into account that it might be best if task running on the dst_cpu should
@@ -1600,7 +1607,7 @@ static void task_numa_compare(struct task_numa_env *env,
goto unlock;
if (!cur) {
- if (maymove || imp > env->best_imp)
+ if (maymove && moveimp >= env->best_imp)
goto assign;
else
goto unlock;
@@ -1643,16 +1650,22 @@ static void task_numa_compare(struct task_numa_env *env,
task_weight(cur, env->dst_nid, dist);
}
- if (imp <= env->best_imp)
- goto unlock;
-
if (maymove && moveimp > imp && moveimp > env->best_imp) {
- imp = moveimp - 1;
+ imp = moveimp;
cur = NULL;
goto assign;
}
/*
+ * If the NUMA importance is less than SMALLIMP,
+ * task migration might only result in ping pong
+ * of tasks and also hurt performance due to cache
+ * misses.
+ */
+ if (imp < SMALLIMP || imp <= env->best_imp + SMALLIMP / 2)
+ goto unlock;
+
+ /*
* In the overloaded case, try and keep the load balanced.
*/
load = task_h_load(env->p) - task_h_load(cur);
--
2.7.4
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [tip:sched/core] sched/numa: Stop multiple tasks from moving to the CPU at the same time
2018-09-21 17:48 ` [PATCH v2 1/6] sched/numa: Stop multiple tasks from moving to the CPU at the same time Srikar Dronamraju
@ 2018-10-02 10:03 ` tip-bot for Srikar Dronamraju
0 siblings, 0 replies; 13+ messages in thread
From: tip-bot for Srikar Dronamraju @ 2018-10-02 10:03 UTC (permalink / raw)
To: linux-tip-commits
Cc: jhladky, mingo, srikar, linux-kernel, torvalds, tglx, efault,
mgorman, hpa, riel, peterz
Commit-ID: a4739eca4456e3d140cc656c5331d42b7465f91d
Gitweb: https://git.kernel.org/tip/a4739eca4456e3d140cc656c5331d42b7465f91d
Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
AuthorDate: Fri, 21 Sep 2018 23:18:56 +0530
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 2 Oct 2018 09:42:20 +0200
sched/numa: Stop multiple tasks from moving to the CPU at the same time
Task migration under NUMA balancing can happen in parallel. More than
one task might choose to migrate to the same CPU at the same time. This
can result in:
- During task swap, choosing a task that was not part of the evaluation.
- During task swap, task which just got moved into its preferred node,
moving to a completely different node.
- During task swap, task failing to move to the preferred node, will have
to wait an extra interval for the next migrate opportunity.
- During task movement, multiple task movements can cause load imbalance.
This problem is more likely if there are more cores per node or more
nodes in the system.
Use a per run-queue variable to check if NUMA-balance is active on the
run-queue.
Specjbb2005 results (8 warehouses)
Higher bops are better
2 Socket - 2 Node Haswell - X86
JVMS Prev Current %Change
4 200194 203353 1.57797
1 311331 328205 5.41995
2 Socket - 4 Node Power8 - PowerNV
JVMS Prev Current %Change
1 197654 214384 8.46429
2 Socket - 2 Node Power9 - PowerNV
JVMS Prev Current %Change
4 192605 188553 -2.10379
1 213402 196273 -8.02664
4 Socket - 4 Node Power7 - PowerVM
JVMS Prev Current %Change
8 52227.1 57581.2 10.2516
1 102529 103468 0.915838
There is a regression on power 9 box. If we look at the details,
that box has a sudden jump in cache-misses with this patch.
All other parameters seem to be pointing towards NUMA
consolidation.
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 13,345,784 13,941,377
migrations 1,127,820 1,157,323
faults 374,736 382,175
cache-misses 55,132,054,603 54,993,823,500
sched:sched_move_numa 1,923 2,005
sched:sched_stick_numa 52 14
sched:sched_swap_numa 595 529
migrate:mm_migrate_pages 1,932 1,573
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 60605 67099
numa_hint_faults_local 51804 58456
numa_hit 239945 240416
numa_huge_pte_updates 14 18
numa_interleave 60 65
numa_local 239865 240339
numa_other 80 77
numa_pages_migrated 1931 1574
numa_pte_updates 67823 77182
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 3,016,467 3,176,453
migrations 37,326 30,238
faults 115,342 87,869
cache-misses 11,692,155,554 12,544,479,391
sched:sched_move_numa 965 23
sched:sched_stick_numa 8 0
sched:sched_swap_numa 35 6
migrate:mm_migrate_pages 1,168 10
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 16286 236
numa_hint_faults_local 11863 201
numa_hit 112482 72293
numa_huge_pte_updates 33 0
numa_interleave 20 26
numa_local 112419 72233
numa_other 63 60
numa_pages_migrated 1144 8
numa_pte_updates 32859 0
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 8,629,724 8,478,820
migrations 221,052 171,323
faults 308,661 307,499
cache-misses 135,574,913 240,353,599
sched:sched_move_numa 147 214
sched:sched_stick_numa 0 0
sched:sched_swap_numa 2 4
migrate:mm_migrate_pages 64 89
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 11481 5301
numa_hint_faults_local 10968 4745
numa_hit 89773 92943
numa_huge_pte_updates 0 0
numa_interleave 1116 899
numa_local 89220 92345
numa_other 553 598
numa_pages_migrated 62 88
numa_pte_updates 11694 5505
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 2,272,887 2,066,172
migrations 12,206 11,076
faults 163,704 149,544
cache-misses 4,801,186 10,398,067
sched:sched_move_numa 44 43
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 0
migrate:mm_migrate_pages 17 6
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 2261 3552
numa_hint_faults_local 1993 3347
numa_hit 25726 25611
numa_huge_pte_updates 0 0
numa_interleave 239 213
numa_local 25498 25583
numa_other 228 28
numa_pages_migrated 17 6
numa_pte_updates 2266 3535
perf stats 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 117,980,962 99,358,136
migrations 3,950,220 4,041,607
faults 736,979 749,653
cache-misses 224,976,072,879 225,562,543,251
sched:sched_move_numa 504 771
sched:sched_stick_numa 50 14
sched:sched_swap_numa 239 204
migrate:mm_migrate_pages 1,260 1,180
vmstat 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 18293 27409
numa_hint_faults_local 11969 20677
numa_hit 240854 239988
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 240851 239983
numa_other 3 5
numa_pages_migrated 1190 1016
numa_pte_updates 18106 27916
perf stats 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 61,053,158 60,899,307
migrations 551,586 544,668
faults 244,174 270,834
cache-misses 74,326,766,973 74,543,455,635
sched:sched_move_numa 344 735
sched:sched_stick_numa 24 25
sched:sched_swap_numa 140 174
migrate:mm_migrate_pages 568 816
vmstat 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 6461 11059
numa_hint_faults_local 2283 4733
numa_hit 35661 41384
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 35661 41383
numa_other 0 1
numa_pages_migrated 568 815
numa_pte_updates 6518 11323
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Jirka Hladky <jhladky@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1537552141-27815-2-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/sched/fair.c | 22 ++++++++++++++++++++++
kernel/sched/sched.h | 1 +
2 files changed, 23 insertions(+)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index f808ddf2a868..3b0b75de1141 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1514,6 +1514,21 @@ struct task_numa_env {
static void task_numa_assign(struct task_numa_env *env,
struct task_struct *p, long imp)
{
+ struct rq *rq = cpu_rq(env->dst_cpu);
+
+ /* Bail out if run-queue part of active NUMA balance. */
+ if (xchg(&rq->numa_migrate_on, 1))
+ return;
+
+ /*
+ * Clear previous best_cpu/rq numa-migrate flag, since task now
+ * found a better CPU to move/swap.
+ */
+ if (env->best_cpu != -1) {
+ rq = cpu_rq(env->best_cpu);
+ WRITE_ONCE(rq->numa_migrate_on, 0);
+ }
+
if (env->best_task)
put_task_struct(env->best_task);
if (p)
@@ -1569,6 +1584,9 @@ static void task_numa_compare(struct task_numa_env *env,
long moveimp = imp;
int dist = env->dist;
+ if (READ_ONCE(dst_rq->numa_migrate_on))
+ return;
+
rcu_read_lock();
cur = task_rcu_dereference(&dst_rq->curr);
if (cur && ((cur->flags & PF_EXITING) || is_idle_task(cur)))
@@ -1710,6 +1728,7 @@ static int task_numa_migrate(struct task_struct *p)
.best_cpu = -1,
};
struct sched_domain *sd;
+ struct rq *best_rq;
unsigned long taskweight, groupweight;
int nid, ret, dist;
long taskimp, groupimp;
@@ -1811,14 +1830,17 @@ static int task_numa_migrate(struct task_struct *p)
*/
p->numa_scan_period = task_scan_start(p);
+ best_rq = cpu_rq(env.best_cpu);
if (env.best_task == NULL) {
ret = migrate_task_to(p, env.best_cpu);
+ WRITE_ONCE(best_rq->numa_migrate_on, 0);
if (ret != 0)
trace_sched_stick_numa(p, env.src_cpu, env.best_cpu);
return ret;
}
ret = migrate_swap(p, env.best_task, env.best_cpu, env.src_cpu);
+ WRITE_ONCE(best_rq->numa_migrate_on, 0);
if (ret != 0)
trace_sched_stick_numa(p, env.src_cpu, task_cpu(env.best_task));
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 4a2e8cae63c4..0b9161241bda 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -783,6 +783,7 @@ struct rq {
#ifdef CONFIG_NUMA_BALANCING
unsigned int nr_numa_running;
unsigned int nr_preferred_running;
+ unsigned int numa_migrate_on;
#endif
#define CPU_LOAD_IDX_MAX 5
unsigned long cpu_load[CPU_LOAD_IDX_MAX];
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [tip:sched/core] sched/numa: Pass destination CPU as a parameter to migrate_task_rq
2018-09-21 17:48 ` [PATCH v2 2/6] sched/numa: Pass destination CPU as a parameter to migrate_task_rq Srikar Dronamraju
@ 2018-10-02 10:03 ` tip-bot for Srikar Dronamraju
0 siblings, 0 replies; 13+ messages in thread
From: tip-bot for Srikar Dronamraju @ 2018-10-02 10:03 UTC (permalink / raw)
To: linux-tip-commits
Cc: hpa, torvalds, efault, mgorman, linux-kernel, riel, peterz,
srikar, mingo, tglx, jhladky
Commit-ID: 1327237a5978b00bcc665c33046c9bae75da1154
Gitweb: https://git.kernel.org/tip/1327237a5978b00bcc665c33046c9bae75da1154
Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
AuthorDate: Fri, 21 Sep 2018 23:18:57 +0530
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 2 Oct 2018 09:42:21 +0200
sched/numa: Pass destination CPU as a parameter to migrate_task_rq
This additional parameter (new_cpu) is used later for identifying if
task migration is across nodes.
No functional change.
Specjbb2005 results (8 warehouses)
Higher bops are better
2 Socket - 2 Node Haswell - X86
JVMS Prev Current %Change
4 203353 200668 -1.32036
1 328205 321791 -1.95427
2 Socket - 4 Node Power8 - PowerNV
JVMS Prev Current %Change
1 214384 204848 -4.44809
2 Socket - 2 Node Power9 - PowerNV
JVMS Prev Current %Change
4 188553 188098 -0.241311
1 196273 200351 2.07772
4 Socket - 4 Node Power7 - PowerVM
JVMS Prev Current %Change
8 57581.2 58145.9 0.980702
1 103468 103798 0.318939
Brings out the variance between different specjbb2005 runs.
Some events stats before and after applying the patch.
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 13,941,377 13,912,183
migrations 1,157,323 1,155,931
faults 382,175 367,139
cache-misses 54,993,823,500 54,240,196,814
sched:sched_move_numa 2,005 1,571
sched:sched_stick_numa 14 9
sched:sched_swap_numa 529 463
migrate:mm_migrate_pages 1,573 703
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 67099 50155
numa_hint_faults_local 58456 45264
numa_hit 240416 239652
numa_huge_pte_updates 18 36
numa_interleave 65 68
numa_local 240339 239576
numa_other 77 76
numa_pages_migrated 1574 680
numa_pte_updates 77182 71146
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 3,176,453 3,156,720
migrations 30,238 30,354
faults 87,869 97,261
cache-misses 12,544,479,391 12,400,026,826
sched:sched_move_numa 23 4
sched:sched_stick_numa 0 0
sched:sched_swap_numa 6 1
migrate:mm_migrate_pages 10 20
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 236 272
numa_hint_faults_local 201 186
numa_hit 72293 71362
numa_huge_pte_updates 0 0
numa_interleave 26 23
numa_local 72233 71299
numa_other 60 63
numa_pages_migrated 8 2
numa_pte_updates 0 0
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 8,478,820 8,606,824
migrations 171,323 155,352
faults 307,499 301,409
cache-misses 240,353,599 157,759,224
sched:sched_move_numa 214 168
sched:sched_stick_numa 0 0
sched:sched_swap_numa 4 3
migrate:mm_migrate_pages 89 125
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 5301 4650
numa_hint_faults_local 4745 3946
numa_hit 92943 90489
numa_huge_pte_updates 0 0
numa_interleave 899 892
numa_local 92345 90034
numa_other 598 455
numa_pages_migrated 88 124
numa_pte_updates 5505 4818
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 2,066,172 2,113,167
migrations 11,076 10,533
faults 149,544 142,727
cache-misses 10,398,067 5,594,192
sched:sched_move_numa 43 10
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 0
migrate:mm_migrate_pages 6 6
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 3552 744
numa_hint_faults_local 3347 584
numa_hit 25611 25551
numa_huge_pte_updates 0 0
numa_interleave 213 263
numa_local 25583 25302
numa_other 28 249
numa_pages_migrated 6 6
numa_pte_updates 3535 744
perf stats 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 99,358,136 101,227,352
migrations 4,041,607 4,151,829
faults 749,653 745,233
cache-misses 225,562,543,251 224,669,561,766
sched:sched_move_numa 771 617
sched:sched_stick_numa 14 2
sched:sched_swap_numa 204 187
migrate:mm_migrate_pages 1,180 316
vmstat 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 27409 24195
numa_hint_faults_local 20677 21639
numa_hit 239988 238331
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 239983 238331
numa_other 5 0
numa_pages_migrated 1016 204
numa_pte_updates 27916 24561
perf stats 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 60,899,307 62,738,978
migrations 544,668 562,702
faults 270,834 228,465
cache-misses 74,543,455,635 75,778,067,952
sched:sched_move_numa 735 648
sched:sched_stick_numa 25 13
sched:sched_swap_numa 174 137
migrate:mm_migrate_pages 816 733
vmstat 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 11059 10281
numa_hint_faults_local 4733 3242
numa_hit 41384 36338
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 41383 36338
numa_other 1 0
numa_pages_migrated 815 706
numa_pte_updates 11323 10176
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jirka Hladky <jhladky@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1537552141-27815-3-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/sched/core.c | 2 +-
kernel/sched/deadline.c | 2 +-
kernel/sched/fair.c | 2 +-
kernel/sched/sched.h | 2 +-
4 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 625bc9897f62..ad97f3ba5ec5 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1167,7 +1167,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
if (task_cpu(p) != new_cpu) {
if (p->sched_class->migrate_task_rq)
- p->sched_class->migrate_task_rq(p);
+ p->sched_class->migrate_task_rq(p, new_cpu);
p->se.nr_migrations++;
rseq_migrate(p);
perf_event_task_migrate(p);
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 997ea7b839fa..91e4202b0634 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1607,7 +1607,7 @@ out:
return cpu;
}
-static void migrate_task_rq_dl(struct task_struct *p)
+static void migrate_task_rq_dl(struct task_struct *p, int new_cpu __maybe_unused)
{
struct rq *rq;
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 3b0b75de1141..bc768156239f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6297,7 +6297,7 @@ static void detach_entity_cfs_rq(struct sched_entity *se);
* cfs_rq_of(p) references at time of call are still valid and identify the
* previous CPU. The caller guarantees p->pi_lock or task_rq(p)->lock is held.
*/
-static void migrate_task_rq_fair(struct task_struct *p)
+static void migrate_task_rq_fair(struct task_struct *p, int new_cpu __maybe_unused)
{
/*
* As blocked tasks retain absolute vruntime the migration needs to
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 0b9161241bda..455fa330de04 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1524,7 +1524,7 @@ struct sched_class {
#ifdef CONFIG_SMP
int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
- void (*migrate_task_rq)(struct task_struct *p);
+ void (*migrate_task_rq)(struct task_struct *p, int new_cpu);
void (*task_woken)(struct rq *this_rq, struct task_struct *task);
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [tip:sched/core] sched/numa: Reset scan rate whenever task moves across nodes
2018-09-21 17:48 ` [PATCH v2 3/6] sched/numa: Reset scan rate whenever task moves across nodes Srikar Dronamraju
@ 2018-10-02 10:04 ` tip-bot for Srikar Dronamraju
0 siblings, 0 replies; 13+ messages in thread
From: tip-bot for Srikar Dronamraju @ 2018-10-02 10:04 UTC (permalink / raw)
To: linux-tip-commits
Cc: riel, hpa, mgorman, linux-kernel, mingo, efault, srikar, peterz,
tglx, jhladky, torvalds
Commit-ID: 3f9672baaa70fc62765857f13f007feb01f9ad33
Gitweb: https://git.kernel.org/tip/3f9672baaa70fc62765857f13f007feb01f9ad33
Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
AuthorDate: Fri, 21 Sep 2018 23:18:58 +0530
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 2 Oct 2018 09:42:23 +0200
sched/numa: Reset scan rate whenever task moves across nodes
Currently task scan rate is reset when NUMA balancer migrates the task
to a different node. If NUMA balancer initiates a swap, reset is only
applicable to the task that initiates the swap. Similarly no scan rate
reset is done if the task is migrated across nodes by traditional load
balancer.
Instead move the scan reset to the migrate_task_rq. This ensures the
task moved out of its preferred node, either gets back to its preferred
node quickly or finds a new preferred node. Doing so, would be fair to
all tasks migrating across nodes.
Specjbb2005 results (8 warehouses)
Higher bops are better
2 Socket - 2 Node Haswell - X86
JVMS Prev Current %Change
4 200668 203370 1.3465
1 321791 328431 2.06345
2 Socket - 4 Node Power8 - PowerNV
JVMS Prev Current %Change
1 204848 206070 0.59654
2 Socket - 2 Node Power9 - PowerNV
JVMS Prev Current %Change
4 188098 188386 0.153112
1 200351 201566 0.606436
4 Socket - 4 Node Power7 - PowerVM
JVMS Prev Current %Change
8 58145.9 59157.4 1.73959
1 103798 105495 1.63491
Some events stats before and after applying the patch.
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 13,912,183 13,825,492
migrations 1,155,931 1,152,509
faults 367,139 371,948
cache-misses 54,240,196,814 55,654,206,041
sched:sched_move_numa 1,571 1,856
sched:sched_stick_numa 9 4
sched:sched_swap_numa 463 428
migrate:mm_migrate_pages 703 898
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 50155 57146
numa_hint_faults_local 45264 51612
numa_hit 239652 238164
numa_huge_pte_updates 36 16
numa_interleave 68 63
numa_local 239576 238085
numa_other 76 79
numa_pages_migrated 680 883
numa_pte_updates 71146 67540
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 3,156,720 3,288,525
migrations 30,354 38,652
faults 97,261 111,678
cache-misses 12,400,026,826 12,111,197,376
sched:sched_move_numa 4 900
sched:sched_stick_numa 0 0
sched:sched_swap_numa 1 5
migrate:mm_migrate_pages 20 714
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 272 18572
numa_hint_faults_local 186 14850
numa_hit 71362 73197
numa_huge_pte_updates 0 11
numa_interleave 23 25
numa_local 71299 73138
numa_other 63 59
numa_pages_migrated 2 712
numa_pte_updates 0 24021
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 8,606,824 8,451,543
migrations 155,352 202,804
faults 301,409 310,024
cache-misses 157,759,224 253,522,507
sched:sched_move_numa 168 213
sched:sched_stick_numa 0 0
sched:sched_swap_numa 3 2
migrate:mm_migrate_pages 125 88
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 4650 11830
numa_hint_faults_local 3946 11301
numa_hit 90489 90038
numa_huge_pte_updates 0 0
numa_interleave 892 855
numa_local 90034 89796
numa_other 455 242
numa_pages_migrated 124 88
numa_pte_updates 4818 12039
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 2,113,167 2,049,153
migrations 10,533 11,405
faults 142,727 162,309
cache-misses 5,594,192 7,203,343
sched:sched_move_numa 10 22
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 0
migrate:mm_migrate_pages 6 1
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 744 1693
numa_hint_faults_local 584 1669
numa_hit 25551 25177
numa_huge_pte_updates 0 0
numa_interleave 263 194
numa_local 25302 24993
numa_other 249 184
numa_pages_migrated 6 1
numa_pte_updates 744 1577
perf stats 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 101,227,352 94,515,937
migrations 4,151,829 4,203,554
faults 745,233 832,697
cache-misses 224,669,561,766 226,248,698,331
sched:sched_move_numa 617 1,730
sched:sched_stick_numa 2 14
sched:sched_swap_numa 187 432
migrate:mm_migrate_pages 316 1,398
vmstat 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 24195 80079
numa_hint_faults_local 21639 68620
numa_hit 238331 241187
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 238331 241186
numa_other 0 1
numa_pages_migrated 204 1347
numa_pte_updates 24561 80729
perf stats 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 62,738,978 63,704,961
migrations 562,702 573,404
faults 228,465 230,878
cache-misses 75,778,067,952 76,568,222,781
sched:sched_move_numa 648 509
sched:sched_stick_numa 13 31
sched:sched_swap_numa 137 182
migrate:mm_migrate_pages 733 541
vmstat 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 10281 8501
numa_hint_faults_local 3242 2960
numa_hit 36338 35526
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 36338 35526
numa_other 0 0
numa_pages_migrated 706 539
numa_pte_updates 10176 8433
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jirka Hladky <jhladky@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1537552141-27815-4-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/sched/fair.c | 26 +++++++++++++++++++-------
1 file changed, 19 insertions(+), 7 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index bc768156239f..5cbfb3068bc6 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1824,12 +1824,6 @@ static int task_numa_migrate(struct task_struct *p)
if (env.best_cpu == -1)
return -EAGAIN;
- /*
- * Reset the scan period if the task is being rescheduled on an
- * alternative node to recheck if the tasks is now properly placed.
- */
- p->numa_scan_period = task_scan_start(p);
-
best_rq = cpu_rq(env.best_cpu);
if (env.best_task == NULL) {
ret = migrate_task_to(p, env.best_cpu);
@@ -2618,6 +2612,18 @@ void task_tick_numa(struct rq *rq, struct task_struct *curr)
}
}
+static void update_scan_period(struct task_struct *p, int new_cpu)
+{
+ int src_nid = cpu_to_node(task_cpu(p));
+ int dst_nid = cpu_to_node(new_cpu);
+
+ if (!p->mm || !p->numa_faults || (p->flags & PF_EXITING))
+ return;
+
+ if (src_nid != dst_nid)
+ p->numa_scan_period = task_scan_start(p);
+}
+
#else
static void task_tick_numa(struct rq *rq, struct task_struct *curr)
{
@@ -2631,6 +2637,10 @@ static inline void account_numa_dequeue(struct rq *rq, struct task_struct *p)
{
}
+static inline void update_scan_period(struct task_struct *p, int new_cpu)
+{
+}
+
#endif /* CONFIG_NUMA_BALANCING */
static void
@@ -6297,7 +6307,7 @@ static void detach_entity_cfs_rq(struct sched_entity *se);
* cfs_rq_of(p) references at time of call are still valid and identify the
* previous CPU. The caller guarantees p->pi_lock or task_rq(p)->lock is held.
*/
-static void migrate_task_rq_fair(struct task_struct *p, int new_cpu __maybe_unused)
+static void migrate_task_rq_fair(struct task_struct *p, int new_cpu)
{
/*
* As blocked tasks retain absolute vruntime the migration needs to
@@ -6350,6 +6360,8 @@ static void migrate_task_rq_fair(struct task_struct *p, int new_cpu __maybe_unus
/* We have migrated, no longer consider this task hot */
p->se.exec_start = 0;
+
+ update_scan_period(p, new_cpu);
}
static void task_dead_fair(struct task_struct *p)
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [tip:sched/core] sched/numa: Limit the conditions where scan period is reset
2018-09-21 17:48 ` [PATCH v2 4/6] sched/numa: Limit the conditions where scan period is reset Srikar Dronamraju
@ 2018-10-02 10:04 ` tip-bot for Mel Gorman
0 siblings, 0 replies; 13+ messages in thread
From: tip-bot for Mel Gorman @ 2018-10-02 10:04 UTC (permalink / raw)
To: linux-tip-commits
Cc: torvalds, srikar, tglx, linux-kernel, jhladky, mgorman, mingo,
peterz, riel, efault, hpa
Commit-ID: 05cbdf4f5c191ff378c47bbf66d7230beb725bdb
Gitweb: https://git.kernel.org/tip/05cbdf4f5c191ff378c47bbf66d7230beb725bdb
Author: Mel Gorman <mgorman@techsingularity.net>
AuthorDate: Fri, 21 Sep 2018 23:18:59 +0530
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 2 Oct 2018 09:42:24 +0200
sched/numa: Limit the conditions where scan period is reset
migrate_task_rq_fair() resets the scan rate for NUMA balancing on every
cross-node migration. In the event of excessive load balancing due to
saturation, this may result in the scan rate being pegged at maximum and
further overloading the machine.
This patch only resets the scan if NUMA balancing is active, a preferred
node has been selected and the task is being migrated from the preferred
node as these are the most harmful. For example, a migration to the preferred
node does not justify a faster scan rate. Similarly, a migration between two
nodes that are not preferred is probably bouncing due to over-saturation of
the machine. In that case, scanning faster and trapping more NUMA faults
will further overload the machine.
Specjbb2005 results (8 warehouses)
Higher bops are better
2 Socket - 2 Node Haswell - X86
JVMS Prev Current %Change
4 203370 205332 0.964744
1 328431 319785 -2.63252
2 Socket - 4 Node Power8 - PowerNV
JVMS Prev Current %Change
1 206070 206585 0.249915
2 Socket - 2 Node Power9 - PowerNV
JVMS Prev Current %Change
4 188386 189162 0.41192
1 201566 213760 6.04963
4 Socket - 4 Node Power7 - PowerVM
JVMS Prev Current %Change
8 59157.4 58736.8 -0.710985
1 105495 105419 -0.0720413
Some events stats before and after applying the patch.
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 13,825,492 14,285,708
migrations 1,152,509 1,180,621
faults 371,948 339,114
cache-misses 55,654,206,041 55,205,631,894
sched:sched_move_numa 1,856 843
sched:sched_stick_numa 4 6
sched:sched_swap_numa 428 219
migrate:mm_migrate_pages 898 365
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 57146 26907
numa_hint_faults_local 51612 24279
numa_hit 238164 239771
numa_huge_pte_updates 16 0
numa_interleave 63 68
numa_local 238085 239688
numa_other 79 83
numa_pages_migrated 883 363
numa_pte_updates 67540 27415
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 3,288,525 3,202,779
migrations 38,652 37,186
faults 111,678 106,076
cache-misses 12,111,197,376 12,024,873,744
sched:sched_move_numa 900 931
sched:sched_stick_numa 0 0
sched:sched_swap_numa 5 1
migrate:mm_migrate_pages 714 637
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 18572 17409
numa_hint_faults_local 14850 14367
numa_hit 73197 73953
numa_huge_pte_updates 11 20
numa_interleave 25 25
numa_local 73138 73892
numa_other 59 61
numa_pages_migrated 712 668
numa_pte_updates 24021 27276
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 8,451,543 8,474,013
migrations 202,804 254,934
faults 310,024 320,506
cache-misses 253,522,507 110,580,458
sched:sched_move_numa 213 725
sched:sched_stick_numa 0 0
sched:sched_swap_numa 2 7
migrate:mm_migrate_pages 88 145
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 11830 22797
numa_hint_faults_local 11301 21539
numa_hit 90038 89308
numa_huge_pte_updates 0 0
numa_interleave 855 865
numa_local 89796 88955
numa_other 242 353
numa_pages_migrated 88 149
numa_pte_updates 12039 22930
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 2,049,153 2,195,628
migrations 11,405 11,179
faults 162,309 149,656
cache-misses 7,203,343 8,117,515
sched:sched_move_numa 22 49
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 0
migrate:mm_migrate_pages 1 5
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 1693 3577
numa_hint_faults_local 1669 3476
numa_hit 25177 26142
numa_huge_pte_updates 0 0
numa_interleave 194 358
numa_local 24993 26042
numa_other 184 100
numa_pages_migrated 1 5
numa_pte_updates 1577 3587
perf stats 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 94,515,937 100,602,296
migrations 4,203,554 4,135,630
faults 832,697 789,256
cache-misses 226,248,698,331 226,160,621,058
sched:sched_move_numa 1,730 1,366
sched:sched_stick_numa 14 16
sched:sched_swap_numa 432 374
migrate:mm_migrate_pages 1,398 1,350
vmstat 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 80079 47857
numa_hint_faults_local 68620 39768
numa_hit 241187 240165
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 241186 240165
numa_other 1 0
numa_pages_migrated 1347 1224
numa_pte_updates 80729 48354
perf stats 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 63,704,961 58,515,496
migrations 573,404 564,845
faults 230,878 245,807
cache-misses 76,568,222,781 73,603,757,976
sched:sched_move_numa 509 996
sched:sched_stick_numa 31 10
sched:sched_swap_numa 182 193
migrate:mm_migrate_pages 541 646
vmstat 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 8501 13422
numa_hint_faults_local 2960 5619
numa_hit 35526 36118
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 35526 36116
numa_other 0 2
numa_pages_migrated 539 616
numa_pte_updates 8433 13374
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jirka Hladky <jhladky@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1537552141-27815-5-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/sched/fair.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 5cbfb3068bc6..3529bf61826b 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2617,11 +2617,32 @@ static void update_scan_period(struct task_struct *p, int new_cpu)
int src_nid = cpu_to_node(task_cpu(p));
int dst_nid = cpu_to_node(new_cpu);
+ if (!static_branch_likely(&sched_numa_balancing))
+ return;
+
if (!p->mm || !p->numa_faults || (p->flags & PF_EXITING))
return;
- if (src_nid != dst_nid)
- p->numa_scan_period = task_scan_start(p);
+ if (src_nid == dst_nid)
+ return;
+
+ /*
+ * Allow resets if faults have been trapped before one scan
+ * has completed. This is most likely due to a new task that
+ * is pulled cross-node due to wakeups or load balancing.
+ */
+ if (p->numa_scan_seq) {
+ /*
+ * Avoid scan adjustments if moving to the preferred
+ * node or if the task was not previously running on
+ * the preferred node.
+ */
+ if (dst_nid == p->numa_preferred_nid ||
+ (p->numa_preferred_nid != -1 && src_nid != p->numa_preferred_nid))
+ return;
+ }
+
+ p->numa_scan_period = task_scan_start(p);
}
#else
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [tip:sched/core] mm/migrate: Use spin_trylock() while resetting rate limit
2018-09-21 17:49 ` [PATCH v2 5/6] mm/migrate: Use trylock while resetting rate limit Srikar Dronamraju
@ 2018-10-02 10:05 ` tip-bot for Srikar Dronamraju
0 siblings, 0 replies; 13+ messages in thread
From: tip-bot for Srikar Dronamraju @ 2018-10-02 10:05 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, peterz, hpa, tglx, torvalds, riel, efault, mingo,
srikar, jhladky, mgorman
Commit-ID: 7534612123e0f5d020aba1076a6bb505db0e6bfe
Gitweb: https://git.kernel.org/tip/7534612123e0f5d020aba1076a6bb505db0e6bfe
Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
AuthorDate: Fri, 21 Sep 2018 23:19:00 +0530
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 2 Oct 2018 09:42:26 +0200
mm/migrate: Use spin_trylock() while resetting rate limit
Since this spinlock will only serialize the migrate rate limiting,
convert the spin_lock() to a spin_trylock(). If another thread is updating, this
task can move on.
Specjbb2005 results (8 warehouses)
Higher bops are better
2 Socket - 2 Node Haswell - X86
JVMS Prev Current %Change
4 205332 198512 -3.32145
1 319785 313559 -1.94693
2 Socket - 4 Node Power8 - PowerNV
JVMS Prev Current %Change
8 74912 74761.9 -0.200368
1 206585 214874 4.01239
2 Socket - 2 Node Power9 - PowerNV
JVMS Prev Current %Change
4 189162 180536 -4.56011
1 213760 210281 -1.62753
4 Socket - 4 Node Power7 - PowerVM
JVMS Prev Current %Change
8 58736.8 56511.4 -3.78877
1 105419 104899 -0.49327
Avoiding stretching of window intervals may be the reason for the
regression. Also code now uses READ_ONCE/WRITE_ONCE. That may
also be hurting performance to some extent.
Some events stats before and after applying the patch.
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 14,285,708 13,818,546
migrations 1,180,621 1,149,960
faults 339,114 385,583
cache-misses 55,205,631,894 55,259,546,768
sched:sched_move_numa 843 2,257
sched:sched_stick_numa 6 9
sched:sched_swap_numa 219 512
migrate:mm_migrate_pages 365 2,225
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 26907 72692
numa_hint_faults_local 24279 62270
numa_hit 239771 238762
numa_huge_pte_updates 0 48
numa_interleave 68 75
numa_local 239688 238676
numa_other 83 86
numa_pages_migrated 363 2225
numa_pte_updates 27415 98557
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 3,202,779 3,173,490
migrations 37,186 36,966
faults 106,076 108,776
cache-misses 12,024,873,744 12,200,075,320
sched:sched_move_numa 931 1,264
sched:sched_stick_numa 0 0
sched:sched_swap_numa 1 0
migrate:mm_migrate_pages 637 899
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 17409 21109
numa_hint_faults_local 14367 17120
numa_hit 73953 72934
numa_huge_pte_updates 20 42
numa_interleave 25 33
numa_local 73892 72866
numa_other 61 68
numa_pages_migrated 668 915
numa_pte_updates 27276 42326
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 8,474,013 8,312,022
migrations 254,934 231,705
faults 320,506 310,242
cache-misses 110,580,458 402,324,573
sched:sched_move_numa 725 193
sched:sched_stick_numa 0 0
sched:sched_swap_numa 7 3
migrate:mm_migrate_pages 145 93
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 22797 11838
numa_hint_faults_local 21539 11216
numa_hit 89308 90689
numa_huge_pte_updates 0 0
numa_interleave 865 1579
numa_local 88955 89634
numa_other 353 1055
numa_pages_migrated 149 92
numa_pte_updates 22930 12109
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 2,195,628 2,170,481
migrations 11,179 10,126
faults 149,656 160,962
cache-misses 8,117,515 10,834,845
sched:sched_move_numa 49 10
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 0
migrate:mm_migrate_pages 5 2
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 3577 403
numa_hint_faults_local 3476 358
numa_hit 26142 25898
numa_huge_pte_updates 0 0
numa_interleave 358 207
numa_local 26042 25860
numa_other 100 38
numa_pages_migrated 5 2
numa_pte_updates 3587 400
perf stats 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 100,602,296 110,339,633
migrations 4,135,630 4,139,812
faults 789,256 863,622
cache-misses 226,160,621,058 231,838,045,660
sched:sched_move_numa 1,366 2,196
sched:sched_stick_numa 16 33
sched:sched_swap_numa 374 544
migrate:mm_migrate_pages 1,350 2,469
vmstat 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 47857 85748
numa_hint_faults_local 39768 66831
numa_hit 240165 242213
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 240165 242211
numa_other 0 2
numa_pages_migrated 1224 2376
numa_pte_updates 48354 86233
perf stats 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 58,515,496 59,331,057
migrations 564,845 552,019
faults 245,807 266,586
cache-misses 73,603,757,976 73,796,312,990
sched:sched_move_numa 996 981
sched:sched_stick_numa 10 54
sched:sched_swap_numa 193 286
migrate:mm_migrate_pages 646 713
vmstat 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 13422 14807
numa_hint_faults_local 5619 5738
numa_hit 36118 36230
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 36116 36228
numa_other 2 2
numa_pages_migrated 616 703
numa_pte_updates 13374 14742
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jirka Hladky <jhladky@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1537552141-27815-6-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
mm/migrate.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index d6a2e89b086a..4f1d894835b5 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1867,16 +1867,24 @@ static unsigned int ratelimit_pages __read_mostly = 128 << (20 - PAGE_SHIFT);
static bool numamigrate_update_ratelimit(pg_data_t *pgdat,
unsigned long nr_pages)
{
+ unsigned long next_window, interval;
+
+ next_window = READ_ONCE(pgdat->numabalancing_migrate_next_window);
+ interval = msecs_to_jiffies(migrate_interval_millisecs);
+
/*
* Rate-limit the amount of data that is being migrated to a node.
* Optimal placement is no good if the memory bus is saturated and
* all the time is being spent migrating!
*/
- if (time_after(jiffies, pgdat->numabalancing_migrate_next_window)) {
- spin_lock(&pgdat->numabalancing_migrate_lock);
+ if (time_after(jiffies, next_window) &&
+ spin_trylock(&pgdat->numabalancing_migrate_lock)) {
pgdat->numabalancing_migrate_nr_pages = 0;
- pgdat->numabalancing_migrate_next_window = jiffies +
- msecs_to_jiffies(migrate_interval_millisecs);
+ do {
+ next_window += interval;
+ } while (unlikely(time_after(jiffies, next_window)));
+
+ WRITE_ONCE(pgdat->numabalancing_migrate_next_window, next_window);
spin_unlock(&pgdat->numabalancing_migrate_lock);
}
if (pgdat->numabalancing_migrate_nr_pages > ratelimit_pages) {
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [tip:sched/core] sched/numa: Avoid task migration for small NUMA improvement
2018-09-21 17:49 ` [PATCH v2 6/6] sched/numa: Avoid task migration for small NUMA improvement Srikar Dronamraju
@ 2018-10-02 10:05 ` tip-bot for Srikar Dronamraju
0 siblings, 0 replies; 13+ messages in thread
From: tip-bot for Srikar Dronamraju @ 2018-10-02 10:05 UTC (permalink / raw)
To: linux-tip-commits
Cc: mingo, riel, tglx, linux-kernel, torvalds, peterz, mgorman, hpa,
srikar, jhladky, efault
Commit-ID: 6fd98e775f24fd41520928d345f5db3ff52bb35d
Gitweb: https://git.kernel.org/tip/6fd98e775f24fd41520928d345f5db3ff52bb35d
Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
AuthorDate: Fri, 21 Sep 2018 23:19:01 +0530
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 2 Oct 2018 09:42:28 +0200
sched/numa: Avoid task migration for small NUMA improvement
If NUMA improvement from the task migration is going to be very
minimal, then avoid task migration.
Specjbb2005 results (8 warehouses)
Higher bops are better
2 Socket - 2 Node Haswell - X86
JVMS Prev Current %Change
4 198512 205910 3.72673
1 313559 318491 1.57291
2 Socket - 4 Node Power8 - PowerNV
JVMS Prev Current %Change
8 74761.9 74935.9 0.232739
1 214874 226796 5.54837
2 Socket - 2 Node Power9 - PowerNV
JVMS Prev Current %Change
4 180536 189780 5.12031
1 210281 205695 -2.18089
4 Socket - 4 Node Power7 - PowerVM
JVMS Prev Current %Change
8 56511.4 60370 6.828
1 104899 108100 3.05151
1/7 cases is regressing, if we look at events migrate_pages seem
to vary the most especially in the regressing case. Also some
amount of variance is expected between different runs of
Specjbb2005.
Some events stats before and after applying the patch.
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 13,818,546 13,801,554
migrations 1,149,960 1,151,541
faults 385,583 433,246
cache-misses 55,259,546,768 55,168,691,835
sched:sched_move_numa 2,257 2,551
sched:sched_stick_numa 9 24
sched:sched_swap_numa 512 904
migrate:mm_migrate_pages 2,225 1,571
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 72692 113682
numa_hint_faults_local 62270 102163
numa_hit 238762 240181
numa_huge_pte_updates 48 36
numa_interleave 75 64
numa_local 238676 240103
numa_other 86 78
numa_pages_migrated 2225 1564
numa_pte_updates 98557 134080
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
cs 3,173,490 3,079,150
migrations 36,966 31,455
faults 108,776 99,081
cache-misses 12,200,075,320 11,588,126,740
sched:sched_move_numa 1,264 1
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 0
migrate:mm_migrate_pages 899 36
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Haswell - X86
Event Before After
numa_hint_faults 21109 430
numa_hint_faults_local 17120 77
numa_hit 72934 71277
numa_huge_pte_updates 42 0
numa_interleave 33 22
numa_local 72866 71218
numa_other 68 59
numa_pages_migrated 915 23
numa_pte_updates 42326 0
perf stats 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 8,312,022 8,707,565
migrations 231,705 171,342
faults 310,242 310,820
cache-misses 402,324,573 136,115,400
sched:sched_move_numa 193 215
sched:sched_stick_numa 0 6
sched:sched_swap_numa 3 24
migrate:mm_migrate_pages 93 162
vmstat 8th warehouse Multi JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 11838 8985
numa_hint_faults_local 11216 8154
numa_hit 90689 93819
numa_huge_pte_updates 0 0
numa_interleave 1579 882
numa_local 89634 93496
numa_other 1055 323
numa_pages_migrated 92 169
numa_pte_updates 12109 9217
perf stats 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
cs 2,170,481 2,152,072
migrations 10,126 10,704
faults 160,962 164,376
cache-misses 10,834,845 3,818,437
sched:sched_move_numa 10 16
sched:sched_stick_numa 0 0
sched:sched_swap_numa 0 7
migrate:mm_migrate_pages 2 199
vmstat 8th warehouse Single JVM 2 Socket - 2 Node Power9 - PowerNV
Event Before After
numa_hint_faults 403 2248
numa_hint_faults_local 358 1666
numa_hit 25898 25704
numa_huge_pte_updates 0 0
numa_interleave 207 200
numa_local 25860 25679
numa_other 38 25
numa_pages_migrated 2 197
numa_pte_updates 400 2234
perf stats 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 110,339,633 93,330,595
migrations 4,139,812 4,122,061
faults 863,622 865,979
cache-misses 231,838,045,660 225,395,083,479
sched:sched_move_numa 2,196 2,372
sched:sched_stick_numa 33 24
sched:sched_swap_numa 544 769
migrate:mm_migrate_pages 2,469 1,677
vmstat 8th warehouse Multi JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 85748 91638
numa_hint_faults_local 66831 78096
numa_hit 242213 242225
numa_huge_pte_updates 0 0
numa_interleave 0 2
numa_local 242211 242219
numa_other 2 6
numa_pages_migrated 2376 1515
numa_pte_updates 86233 92274
perf stats 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
cs 59,331,057 51,487,271
migrations 552,019 537,170
faults 266,586 256,921
cache-misses 73,796,312,990 70,073,831,187
sched:sched_move_numa 981 576
sched:sched_stick_numa 54 24
sched:sched_swap_numa 286 327
migrate:mm_migrate_pages 713 726
vmstat 8th warehouse Single JVM 4 Socket - 4 Node Power7 - PowerVM
Event Before After
numa_hint_faults 14807 12000
numa_hint_faults_local 5738 5024
numa_hit 36230 36470
numa_huge_pte_updates 0 0
numa_interleave 0 0
numa_local 36228 36465
numa_other 2 5
numa_pages_migrated 703 726
numa_pte_updates 14742 11930
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jirka Hladky <jhladky@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1537552141-27815-7-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/sched/fair.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 3529bf61826b..25c7c7e09cbd 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1567,6 +1567,13 @@ static bool load_too_imbalanced(long src_load, long dst_load,
return (imb > old_imb);
}
+/*
+ * Maximum NUMA importance can be 1998 (2*999);
+ * SMALLIMP @ 30 would be close to 1998/64.
+ * Used to deter task migration.
+ */
+#define SMALLIMP 30
+
/*
* This checks if the overall compute and NUMA accesses of the system would
* be improved if the source tasks was migrated to the target dst_cpu taking
@@ -1600,7 +1607,7 @@ static void task_numa_compare(struct task_numa_env *env,
goto unlock;
if (!cur) {
- if (maymove || imp > env->best_imp)
+ if (maymove && moveimp >= env->best_imp)
goto assign;
else
goto unlock;
@@ -1643,15 +1650,21 @@ static void task_numa_compare(struct task_numa_env *env,
task_weight(cur, env->dst_nid, dist);
}
- if (imp <= env->best_imp)
- goto unlock;
-
if (maymove && moveimp > imp && moveimp > env->best_imp) {
- imp = moveimp - 1;
+ imp = moveimp;
cur = NULL;
goto assign;
}
+ /*
+ * If the NUMA importance is less than SMALLIMP,
+ * task migration might only result in ping pong
+ * of tasks and also hurt performance due to cache
+ * misses.
+ */
+ if (imp < SMALLIMP || imp <= env->best_imp + SMALLIMP / 2)
+ goto unlock;
+
/*
* In the overloaded case, try and keep the load balanced.
*/
^ permalink raw reply related [flat|nested] 13+ messages in thread
end of thread, other threads:[~2018-10-02 10:06 UTC | newest]
Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-09-21 17:48 [PATCH v2 0/6] numabalancing patches Srikar Dronamraju
2018-09-21 17:48 ` [PATCH v2 1/6] sched/numa: Stop multiple tasks from moving to the CPU at the same time Srikar Dronamraju
2018-10-02 10:03 ` [tip:sched/core] " tip-bot for Srikar Dronamraju
2018-09-21 17:48 ` [PATCH v2 2/6] sched/numa: Pass destination CPU as a parameter to migrate_task_rq Srikar Dronamraju
2018-10-02 10:03 ` [tip:sched/core] " tip-bot for Srikar Dronamraju
2018-09-21 17:48 ` [PATCH v2 3/6] sched/numa: Reset scan rate whenever task moves across nodes Srikar Dronamraju
2018-10-02 10:04 ` [tip:sched/core] " tip-bot for Srikar Dronamraju
2018-09-21 17:48 ` [PATCH v2 4/6] sched/numa: Limit the conditions where scan period is reset Srikar Dronamraju
2018-10-02 10:04 ` [tip:sched/core] " tip-bot for Mel Gorman
2018-09-21 17:49 ` [PATCH v2 5/6] mm/migrate: Use trylock while resetting rate limit Srikar Dronamraju
2018-10-02 10:05 ` [tip:sched/core] mm/migrate: Use spin_trylock() " tip-bot for Srikar Dronamraju
2018-09-21 17:49 ` [PATCH v2 6/6] sched/numa: Avoid task migration for small NUMA improvement Srikar Dronamraju
2018-10-02 10:05 ` [tip:sched/core] " tip-bot for Srikar Dronamraju
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