kernel_optimize_test/mm
Henry Willard 859d4adc34 mm: numa: do not trap faults on shared data section pages.
Workloads consisting of a large number of processes running the same
program with a very large shared data segment may experience performance
problems when numa balancing attempts to migrate the shared cow pages.
This manifests itself with many processes or tasks in
TASK_UNINTERRUPTIBLE state waiting for the shared pages to be migrated.

The program listed below simulates the conditions with these results
when run with 288 processes on a 144 core/8 socket machine.

Average throughput 	Average throughput     Average throughput
with numa_balancing=0	with numa_balancing=1  with numa_balancing=1
     			without the patch      with the patch
---------------------	---------------------  ---------------------
2118782			2021534		       2107979

Complex production environments show less variability and fewer poorly
performing outliers accompanied with a smaller number of processes
waiting on NUMA page migration with this patch applied.  In some cases,
%iowait drops from 16%-26% to 0.

  // SPDX-License-Identifier: GPL-2.0
  /*
   * Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
   */
  #include <sys/time.h>
  #include <stdio.h>
  #include <wait.h>
  #include <sys/mman.h>

  int a[1000000] = {13};

  int  main(int argc, const char **argv)
  {
	int n = 0;
	int i;
	pid_t pid;
	int stat;
	int *count_array;
	int cpu_count = 288;
	long total = 0;

	struct timeval t1, t2 = {(argc > 1 ? atoi(argv[1]) : 10), 0};

	if (argc > 2)
		cpu_count = atoi(argv[2]);

	count_array = mmap(NULL, cpu_count * sizeof(int),
			   (PROT_READ|PROT_WRITE),
			   (MAP_SHARED|MAP_ANONYMOUS), 0, 0);

	if (count_array == MAP_FAILED) {
		perror("mmap:");
		return 0;
	}

	for (i = 0; i < cpu_count; ++i) {
		pid = fork();
		if (pid <= 0)
			break;
		if ((i & 0xf) == 0)
			usleep(2);
	}

	if (pid != 0) {
		if (i == 0) {
			perror("fork:");
			return 0;
		}

		for (;;) {
			pid = wait(&stat);
			if (pid < 0)
				break;
		}

		for (i = 0; i < cpu_count; ++i)
			total += count_array[i];

		printf("Total %ld\n", total);
		munmap(count_array, cpu_count * sizeof(int));
		return 0;
	}

	gettimeofday(&t1, 0);
	timeradd(&t1, &t2, &t1);
	while (timercmp(&t2, &t1, <)) {
		int b = 0;
		int j;

		for (j = 0; j < 1000000; j++)
			b += a[j];
		gettimeofday(&t2, 0);
		n++;
	}
	count_array[i] = n;
	return 0;
  }

This patch changes change_pte_range() to skip shared copy-on-write pages
when called from change_prot_numa().

NOTE: change_prot_numa() is nominally called from task_numa_work() and
queue_pages_test_walk().  task_numa_work() is the auto NUMA balancing
path, and queue_pages_test_walk() is part of explicit NUMA policy
management.  However, queue_pages_test_walk() only calls
change_prot_numa() when MPOL_MF_LAZY is specified and currently that is
not allowed, so change_prot_numa() is only called from auto NUMA
balancing.

In the case of explicit NUMA policy management, shared pages are not
migrated unless MPOL_MF_MOVE_ALL is specified, and MPOL_MF_MOVE_ALL
depends on CAP_SYS_NICE.  Currently, there is no way to pass information
about MPOL_MF_MOVE_ALL to change_pte_range.  This will have to be fixed
if MPOL_MF_LAZY is enabled and MPOL_MF_MOVE_ALL is to be honored in lazy
migration mode.

task_numa_work() skips the read-only VMAs of programs and shared
libraries.

Link: http://lkml.kernel.org/r/1516751617-7369-1-git-send-email-henry.willard@oracle.com
Signed-off-by: Henry Willard <henry.willard@oracle.com>
Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com>
Reviewed-by: Steve Sistare <steven.sistare@oracle.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31 17:18:40 -08:00
..
kasan kasan: use %px to print addresses instead of %p 2017-11-29 12:13:16 +11:00
backing-dev.c Revert "bdi: add error handle for bdi_debug_register" 2017-12-21 10:01:30 -07:00
balloon_compaction.c virtio_balloon: fix deadlock on OOM 2017-11-14 23:57:38 +02:00
bootmem.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cleancache.c
cma_debug.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cma.c mm/cma.c: change pr_info to pr_err for cma_alloc fail log 2017-11-15 18:21:03 -08:00
cma.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compaction.c mm/compaction.c: fix comment for try_to_compact_pages() 2018-01-31 17:18:39 -08:00
debug_page_ref.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
debug.c mm/debug.c: provide useful debugging information for VM_BUG 2018-01-04 16:45:09 -08:00
dmapool.c
early_ioremap.c mm/early_ioremap: Fix boot hang with earlyprintk=efi,keep 2017-12-11 14:54:44 +01:00
fadvise.c mm/fadvise: discard partial page if endbyte is also EOF 2018-01-31 17:18:39 -08:00
failslab.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
filemap.c mm/filemap.c: remove include of hardirq.h 2018-01-31 17:18:36 -08:00
frame_vector.c mm/frame_vector.c: release a semaphore in 'get_vaddr_frames()' 2017-12-14 16:00:48 -08:00
frontswap.c
gup_benchmark.c mm: add infrastructure for get_user_pages_fast() benchmarking 2017-11-17 16:10:04 -08:00
gup.c Merge branch 'work.get_user_pages_fast' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-31 10:01:08 -08:00
highmem.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hmm.c mm/hmm: fix uninitialized use of 'entry' in hmm_vma_walk_pmd() 2018-01-31 17:18:40 -08:00
huge_memory.c mm/thp: remove pmd_huge_split_prepare() 2018-01-31 17:18:38 -08:00
hugetlb_cgroup.c
hugetlb.c hugetlb, mbind: fall back to default policy if vma is NULL 2018-01-31 17:18:40 -08:00
hwpoison-inject.c mm/memory_failure: Remove unused trapno from memory_failure 2018-01-23 12:17:42 -06:00
init-mm.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
internal.h Revert "mm, thp: Do not make pmd/pud dirty without a reason" 2017-11-29 09:01:01 -08:00
interval_tree.c mm/interval_tree.c: use vma_pages() helper 2018-01-31 17:18:37 -08:00
Kconfig mm: relax deferred struct page requirements 2018-01-31 17:18:36 -08:00
Kconfig.debug kmemcheck: rip it out 2017-11-15 18:21:05 -08:00
khugepaged.c mm: thp: use down_read_trylock() in khugepaged to avoid long block 2018-01-31 17:18:38 -08:00
kmemleak-test.c
kmemleak.c mm: kmemleak: remove unused hardirq.h 2018-01-31 17:18:36 -08:00
ksm.c mm/ksm: Remove now-redundant smp_read_barrier_depends() 2017-12-04 10:52:56 -08:00
list_lru.c mm/list_lru.c: mark expected switch fall-through 2017-11-15 18:21:07 -08:00
maccess.c
madvise.c mm/memory_failure: Remove unused trapno from memory_failure 2018-01-23 12:17:42 -06:00
Makefile mm: add infrastructure for get_user_pages_fast() benchmarking 2017-11-17 16:10:04 -08:00
memblock.c mm: define memblock_virt_alloc_try_nid_raw 2017-11-15 18:21:05 -08:00
memcontrol.c mm/memcontrol.c: try harder to decrease [memory,memsw].limit_in_bytes 2018-01-31 17:18:40 -08:00
memory_hotplug.c mm: memory_hotplug: remove second __nr_to_section in register_page_bootmem_info_section() 2018-01-31 17:18:37 -08:00
memory-failure.c signal/memory-failure: Use force_sig_mceerr and send_sig_mceerr 2018-01-23 12:17:48 -06:00
memory.c mm: add unmap_mapping_pages() 2018-01-31 17:18:37 -08:00
mempolicy.c hugetlb, mbind: fall back to default policy if vma is NULL 2018-01-31 17:18:40 -08:00
mempool.c mm/mempool.c: use kmalloc_array_node() 2017-11-15 18:21:02 -08:00
memtest.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
migrate.c mm, hugetlb: do not rely on overcommit limit during migration 2018-01-31 17:18:40 -08:00
mincore.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mlock.c mm: Eliminate cond_resched_rcu_qs() in favor of cond_resched() 2017-11-28 16:00:28 -08:00
mm_init.c
mmap.c mm, oom_reaper: fix memory corruption 2017-12-14 16:00:49 -08:00
mmu_context.c
mmu_notifier.c mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks 2018-01-31 17:18:38 -08:00
mmzone.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mprotect.c mm: numa: do not trap faults on shared data section pages. 2018-01-31 17:18:40 -08:00
mremap.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
msync.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
nobootmem.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
nommu.c mm: add unmap_mapping_pages() 2018-01-31 17:18:37 -08:00
oom_kill.c mm, oom: avoid reaping only for mm's with blockable invalidate callbacks 2018-01-31 17:18:38 -08:00
page_alloc.c mm/page_alloc.c: fix typos in comments 2018-01-31 17:18:39 -08:00
page_counter.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page_ext.c mm/page_ext.c: make page_ext_init a noop when CONFIG_PAGE_EXTENSION but nothing uses it 2018-01-31 17:18:39 -08:00
page_idle.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page_io.c block: convert to bio_first_bvec_all & bio_first_page_all 2018-01-06 09:18:00 -07:00
page_isolation.c mm: distinguish CMA and MOVABLE isolation in has_unmovable_pages() 2017-11-15 18:21:02 -08:00
page_owner.c mm/page_owner.c: clean up init_pages_in_zone() 2018-01-31 17:18:39 -08:00
page_poison.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page_vma_mapped.c mm, page_vma_mapped: Introduce pfn_in_hpage() 2018-01-22 12:15:57 -08:00
page-writeback.c Revert "mm/page-writeback.c: print a warning if the vm dirtiness settings are illogical" 2017-11-29 18:40:43 -08:00
pagewalk.c mm/pagewalk.c: report holes in hugetlb ranges 2017-11-15 13:12:08 -08:00
percpu-internal.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
percpu-km.c
percpu-stats.c percpu: fix starting offset for chunk statistics traversal 2017-09-27 14:45:57 -07:00
percpu-vm.c mm: remove __GFP_COLD 2017-11-15 18:21:06 -08:00
percpu.c percpu: hack to let the CRIS architecture to boot until they clean up 2017-11-27 12:53:12 -08:00
pgtable-generic.c mm: do not lose dirty and accessed bits in pmdp_invalidate() 2018-01-31 17:18:38 -08:00
process_vm_access.c
quicklist.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
readahead.c
rmap.c mm: remove cold parameter from free_hot_cold_page* 2017-11-15 18:21:06 -08:00
rodata_test.c mm: fix RODATA_TEST failure "rodata_test: test data was not read only" 2017-10-03 17:54:24 -07:00
shmem.c shmem: add sealing support to hugetlb-backed memfd 2018-01-31 17:18:39 -08:00
slab_common.c mm/slab_common.c: make calculate_alignment() static 2018-01-31 17:18:35 -08:00
slab.c mm/slab.c: remove redundant assignments for slab_state 2018-01-31 17:18:35 -08:00
slab.h mm/slab_common.c: make calculate_alignment() static 2018-01-31 17:18:35 -08:00
slob.c slab, slub, slob: add slab_flags_t 2017-11-15 18:21:01 -08:00
slub.c slub: remove obsolete comments of put_cpu_partial() 2018-01-31 17:18:36 -08:00
sparse-vmemmap.c mm, sparse: do not swamp log with huge vmemmap allocation failures 2017-11-15 18:21:07 -08:00
sparse.c include/linux/mmzone.h: fix explanation of lower bits in the SPARSEMEM mem_map pointer 2018-01-31 17:18:39 -08:00
swap_cgroup.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swap_slots.c mm/swap_slots.c: fix race conditions in swap_slots cache init 2017-11-15 18:21:03 -08:00
swap_state.c mm: remove cold parameter for release_pages 2017-11-15 18:21:06 -08:00
swap.c mm: drop hotplug lock from lru_add_drain_all() 2018-01-31 17:18:36 -08:00
swapfile.c ipc, kernel, mm: annotate ->poll() instances 2017-11-27 16:20:05 -05:00
truncate.c mm: add unmap_mapping_pages() 2018-01-31 17:18:37 -08:00
usercopy.c
userfaultfd.c userfaultfd: shmem: wire up shmem_mfill_zeropage_pte 2017-09-06 17:27:28 -07:00
util.c new primitive: vmemdup_user() 2018-01-07 13:06:15 -05:00
vmacache.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
vmalloc.c Revert "vmalloc: back off when the current task is killed" 2017-10-13 16:18:32 -07:00
vmpressure.c
vmscan.c mm: pin address_space before dereferencing it while isolating an LRU page 2018-01-31 17:18:39 -08:00
vmstat.c mm, sysctl: make NUMA stats configurable 2017-11-15 18:21:07 -08:00
workingset.c mm, truncate: do not check mapping for every page being truncated 2017-11-15 18:21:06 -08:00
z3fold.c mm/z3fold.c: use kref to prevent page free/compact race 2017-11-17 16:10:00 -08:00
zbud.c
zpool.c zswap: only save zswap header when necessary 2018-01-31 17:18:39 -08:00
zsmalloc.c zsmalloc: use U suffix for negative literals being shifted 2018-01-31 17:18:39 -08:00
zswap.c zswap: only save zswap header when necessary 2018-01-31 17:18:39 -08:00