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| author | Srikar Dronamraju <srikar@linux.vnet.ibm.com> | 2018-09-21 23:19:00 +0530 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-10-02 09:42:26 +0200 |
| commit | 7534612123e0f5d020aba1076a6bb505db0e6bfe (patch) | |
| tree | 70f3cbde7747bc0fc707ea59e0256b97775f2a00 /mm/migrate.c | |
| parent | 05cbdf4f5c191ff378c47bbf66d7230beb725bdb (diff) | |
| download | linux-7534612123e0f5d020aba1076a6bb505db0e6bfe.tar.gz linux-7534612123e0f5d020aba1076a6bb505db0e6bfe.tar.bz2 linux-7534612123e0f5d020aba1076a6bb505db0e6bfe.zip | |
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>
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 16 |
1 files 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) { |