Saravanan D 575299ea18 x86/mm: track linear mapping split events ... To help with debugging the sluggishness caused by TLB miss/reload, we introduce monotonic hugepage [direct mapped] split event counts since system state: SYSTEM_RUNNING to be displayed as part of /proc/vmstat in x86 servers The lifetime split event information will be displayed at the bottom of /proc/vmstat .... swap_ra 0 swap_ra_hit 0 direct_map_level2_splits 94 direct_map_level3_splits 4 nr_unstable 0 .... One of the many lasting sources of direct hugepage splits is kernel tracing (kprobes, tracepoints). Note that the kernel's code segment [512 MB] points to the same physical addresses that have been already mapped in the kernel's direct mapping range. Source : Documentation/x86/x86_64/mm.rst When we enable kernel tracing, the kernel has to modify attributes/permissions of the text segment hugepages that are direct mapped causing them to split. Kernel's direct mapped hugepages do not coalesce back after split and remain in place for the remainder of the lifetime. An instance of direct page splits when we turn on dynamic kernel tracing .... cat /proc/vmstat | grep -i direct_map_level direct_map_level2_splits 784 direct_map_level3_splits 12 bpftrace -e 'tracepoint:raw_syscalls:sys_enter { @ [pid, comm] = count(); }' cat /proc/vmstat | grep -i direct_map_level direct_map_level2_splits 789 direct_map_level3_splits 12 .... Link: https://lkml.kernel.org/r/20210218235744.1040634-1-saravanand@fb.com Signed-off-by: Saravanan D <saravanand@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2021-05-05 11:27:25 -07:00
..
kasan	kasan: record task_work_add() call stack	2021-04-30 11:20:42 -07:00
kfence	kfence: make compatible with kmemleak	2021-03-25 09:22:55 -07:00
backing-dev.c	mm/backing-dev.c: use might_alloc()	2021-02-26 09:41:01 -08:00
balloon_compaction.c
cleancache.c
cma_debug.c	mm/cma: change cma mutex to irq safe spinlock	2021-05-05 11:27:21 -07:00
cma_sysfs.c	mm: cma: support sysfs	2021-05-05 11:27:24 -07:00
cma.c	mm: use proper type for cma_[alloc|release]	2021-05-05 11:27:24 -07:00
cma.h	mm: cma: support sysfs	2021-05-05 11:27:24 -07:00
compaction.c	mm: replace migrate_[prep|finish] with lru_cache_[disable|enable]	2021-05-05 11:27:24 -07:00
debug_page_ref.c
debug_vm_pgtable.c	mm: HUGE_VMAP arch support cleanup	2021-04-30 11:20:40 -07:00
debug.c	mm/debug: improve memcg debugging	2021-02-24 13:38:27 -08:00
dmapool.c	mm/dmapool: switch from strlcpy to strscpy	2021-04-30 11:20:39 -07:00
early_ioremap.c	mm/early_ioremap.c: use __func__ instead of function name	2021-02-26 09:41:02 -08:00
fadvise.c	mm, fadvise: improve the expensive remote LRU cache draining after FADV_DONTNEED	2020-10-13 18:38:29 -07:00
failslab.c
filemap.c	dax: account DAX entries as nrpages	2021-05-05 11:27:19 -07:00
frontswap.c	mm/frontswap: mark various intentional data races	2020-08-14 19:56:56 -07:00
gup_test.c	mm/gup_test.c: mark gup_test_init as __init function	2020-12-15 12:13:38 -08:00
gup_test.h	selftests/vm: gup_test: introduce the dump_pages() sub-test	2020-12-15 12:13:38 -08:00
gup.c	mm: gup: remove FOLL_SPLIT	2021-04-30 11:20:37 -07:00
highmem.c	mm/highmem: fix CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP	2021-03-25 09:22:55 -07:00
hmm.c	mm: do page fault accounting in handle_mm_fault	2020-08-12 10:58:02 -07:00
huge_memory.c	mm: vmscan: consolidate shrinker_maps handling code	2021-05-05 11:27:23 -07:00
hugetlb_cgroup.c	hugetlb: make free_huge_page irq safe	2021-05-05 11:27:22 -07:00
hugetlb.c	userfaultfd: add UFFDIO_CONTINUE ioctl	2021-05-05 11:27:22 -07:00
hwpoison-inject.c	mm,hwpoison-inject: don't pin for hwpoison_filter	2020-10-16 11:11:16 -07:00
init-mm.c	mm/gup: prevent gup_fast from racing with COW during fork	2020-12-15 12:13:39 -08:00
internal.h	mm,compaction: let isolate_migratepages_{range,block} return error codes	2021-05-05 11:27:22 -07:00
interval_tree.c	mm/interval_tree: add comments to improve code readability	2021-04-30 11:20:38 -07:00
io-mapping.c	mm: add a io_mapping_map_user helper	2021-04-30 11:20:39 -07:00
ioremap.c	mm: move vmap_range from mm/ioremap.c to mm/vmalloc.c	2021-04-30 11:20:40 -07:00
Kconfig	mm: cma: support sysfs	2021-05-05 11:27:24 -07:00
Kconfig.debug	mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO	2020-12-15 12:13:46 -08:00
khugepaged.c	mm/vmscan: replace implicit RECLAIM_ZONE checks with explicit checks	2021-05-05 11:27:23 -07:00
kmemleak.c	mm/kmemleak.c: fix a typo	2021-04-30 11:20:36 -07:00
ksm.c	mm/ksm: remove unused parameter from remove_trailing_rmap_items()	2021-05-05 11:27:25 -07:00
list_lru.c	mm: vmscan: consolidate shrinker_maps handling code	2021-05-05 11:27:23 -07:00
maccess.c	uaccess: add force_uaccess_{begin,end} helpers	2020-08-12 10:57:59 -07:00
madvise.c	mm/madvise: replace ptrace attach requirement for process_madvise	2021-03-13 11:27:30 -08:00
Makefile	mm: cma: support sysfs	2021-05-05 11:27:24 -07:00
mapping_dirty_helpers.c	mm/mapping_dirty_helpers: guard hugepage pud's usage	2021-04-16 16:10:37 -07:00
memblock.c	memblock: remove return value of memblock_free_all()	2021-02-22 13:01:23 -08:00
memcontrol.c	mm: memcontrol: reparent nr_deferred when memcg offline	2021-05-05 11:27:23 -07:00
memfd.c
memory_hotplug.c	mm: disable LRU pagevec during the migration temporarily	2021-05-05 11:27:24 -07:00
memory-failure.c	mm/memory-failure: unnecessary amount of unmapping	2021-04-30 11:20:44 -07:00
memory.c	mm: apply_to_pte_range warn and fail if a large pte is encountered	2021-04-30 11:20:39 -07:00
mempolicy.c	mm: replace migrate_[prep|finish] with lru_cache_[disable|enable]	2021-05-05 11:27:24 -07:00
mempool.c	kasan, mm: integrate page_alloc init with HW_TAGS	2021-04-30 11:20:41 -07:00
memremap.c	mm/memremap.c: fix improper SPDX comment style	2021-04-30 11:20:37 -07:00
memtest.c
migrate.c	mm: cma: add trace events for CMA alloc perf testing	2021-05-05 11:27:24 -07:00
mincore.c	inode: make init and permission helpers idmapped mount aware	2021-01-24 14:27:16 +01:00
mlock.c	mm/mlock: stop counting mlocked pages when none vma is found	2021-02-26 09:41:01 -08:00
mm_init.c	include/linux/page-flags-layout.h: cleanups	2021-04-30 11:20:42 -07:00
mmap_lock.c	mm: mmap_lock: add tracepoints around lock acquisition	2020-12-15 12:13:41 -08:00
mmap.c	Revert "mremap: don't allow MREMAP_DONTUNMAP on special_mappings and aio"	2021-04-30 11:20:39 -07:00
mmu_gather.c	mm: eliminate "expecting prototype" kernel-doc warnings	2021-04-16 16:10:36 -07:00
mmu_notifier.c	mm/mmu_notifiers: ensure range_end() is paired with range_start()	2021-03-25 09:22:55 -07:00
mmzone.c	mm/lru: replace pgdat lru_lock with lruvec lock	2020-12-15 14:48:04 -08:00
mprotect.c	mm/mprotect.c: optimize error detection in do_mprotect_pkey()	2021-02-24 13:38:30 -08:00
mremap.c	Revert "mremap: don't allow MREMAP_DONTUNMAP on special_mappings and aio"	2021-04-30 11:20:39 -07:00
msync.c	mm/msync: exit early when the flags is an MS_ASYNC and start < vm_start	2021-04-30 11:20:37 -07:00
nommu.c	mm/nommu: Fix return type of filemap_map_pages()	2021-01-28 14:10:31 +00:00
oom_kill.c	mm: eliminate "expecting prototype" kernel-doc warnings	2021-04-16 16:10:36 -07:00
page_alloc.c	mm: use proper type for cma_[alloc|release]	2021-05-05 11:27:24 -07:00
page_counter.c	mm: page_counter: mitigate consequences of a page_counter underflow	2021-04-30 11:20:38 -07:00
page_ext.c	mm: fix some spelling mistakes in comments	2020-12-15 22:46:19 -08:00
page_idle.c	mm: page_idle_get_page() does not need lru_lock	2020-12-15 14:48:03 -08:00
page_io.c	swap: fix swapfile read/write offset	2021-03-02 17:25:46 -07:00
page_isolation.c	mm/page_isolation: do not isolate the max order page	2020-12-15 12:13:45 -08:00
page_owner.c	mm: page_owner: detect page_owner recursion via task_struct	2021-04-30 11:20:36 -07:00
page_poison.c	mm: page_poison: print page info when corruption is caught	2021-04-30 11:20:36 -07:00
page_reporting.c	mm/page_reporting: use list_entry_is_head() in page_reporting_cycle()	2021-02-24 13:38:30 -08:00
page_reporting.h
page_vma_mapped.c	mm/page_vma_mapped.c: add colon to fix kernel-doc markups error for check_pte	2020-12-15 12:13:41 -08:00
page-writeback.c	mm: page-writeback: simplify memcg handling in test_clear_page_writeback()	2021-04-30 11:20:37 -07:00
pagewalk.c
percpu-internal.h	percpu: make pcpu_nr_empty_pop_pages per chunk type	2021-04-09 13:58:38 +00:00
percpu-km.c	mm: memcg/percpu: account percpu memory to memory cgroups	2020-08-12 10:57:55 -07:00
percpu-stats.c	percpu: make pcpu_nr_empty_pop_pages per chunk type	2021-04-09 13:58:38 +00:00
percpu-vm.c	mm/vmalloc: remove unmap_kernel_range	2021-04-30 11:20:40 -07:00
percpu.c	percpu: make pcpu_nr_empty_pop_pages per chunk type	2021-04-09 13:58:38 +00:00
pgalloc-track.h	mm: move p?d_alloc_track to separate header file	2020-08-07 11:33:26 -07:00
pgtable-generic.c	mm/pgtable-generic.c: optimize the VM_BUG_ON condition in pmdp_huge_clear_flush()	2021-02-24 13:38:30 -08:00
process_vm_access.c	mm/process_vm_access.c: include compat.h	2021-01-12 18:12:54 -08:00
ptdump.c	mm: ptdump: fix build failure	2021-04-16 16:10:37 -07:00
readahead.c	mm: Implement readahead_control pageset expansion	2021-04-23 10:14:29 +01:00
rmap.c	mm/rmap: correct obsolete comment of page_get_anon_vma()	2021-02-26 09:41:01 -08:00
rodata_test.c	mm/rodata_test.c: fix missing function declaration	2020-08-21 09:52:53 -07:00
shmem.c	shmem: allow reporting fanotify events with file handles on tmpfs	2021-04-19 16:03:48 +02:00
shuffle.c	mm: eliminate "expecting prototype" kernel-doc warnings	2021-04-16 16:10:36 -07:00
shuffle.h	mm/shuffle: remove dynamic reconfiguration	2020-08-07 11:33:29 -07:00
slab_common.c	mm/slab_common: provide "slab_merge" option for !IS_ENABLED(CONFIG_SLAB_MERGE_DEFAULT) builds	2021-04-30 11:20:36 -07:00
slab.c	kasan, mm: integrate slab init_on_free with HW_TAGS	2021-04-30 11:20:41 -07:00
slab.h	kasan, mm: integrate slab init_on_alloc with HW_TAGS	2021-04-30 11:20:41 -07:00
slob.c	mm: Don't build mm_dump_obj() on CONFIG_PRINTK=n kernels	2021-03-08 14:18:46 -08:00
slub.c	kasan, mm: integrate slab init_on_free with HW_TAGS	2021-04-30 11:20:41 -07:00
sparse-vmemmap.c	mm/sparse: only sub-section aligned range would be populated	2020-08-07 11:33:27 -07:00
sparse.c	mm/sparse: add the missing sparse_buffer_fini() in error branch	2021-04-30 11:20:39 -07:00
swap_cgroup.c
swap_slots.c	mm/swap_slots.c: remove redundant NULL check	2021-02-24 13:38:28 -08:00
swap_state.c	mm: stop accounting shadow entries	2021-05-05 11:27:19 -07:00
swap.c	mm: fs: invalidate BH LRU during page migration	2021-05-05 11:27:24 -07:00
swapfile.c	swap: fix swapfile read/write offset	2021-03-02 17:25:46 -07:00
truncate.c	mm: stop accounting shadow entries	2021-05-05 11:27:19 -07:00
usercopy.c	mm/usercopy.c: delete duplicated word	2020-08-12 10:57:58 -07:00
userfaultfd.c	userfaultfd: add UFFDIO_CONTINUE ioctl	2021-05-05 11:27:22 -07:00
util.c	mm: move page_mapping_file to pagemap.h	2021-04-30 11:20:37 -07:00
vmacache.c
vmalloc.c	mm/vmalloc: remove an empty line	2021-04-30 11:20:40 -07:00
vmpressure.c
vmscan.c	mm: vmscan: shrink deferred objects proportional to priority	2021-05-05 11:27:23 -07:00
vmstat.c	x86/mm: track linear mapping split events	2021-05-05 11:27:25 -07:00
workingset.c	mm: stop accounting shadow entries	2021-05-05 11:27:19 -07:00
z3fold.c	z3fold: prevent reclaim/free race for headless pages	2021-03-25 09:22:55 -07:00
zbud.c	mm: set the sleep_mapped to true for zbud and z3fold	2021-02-26 09:41:01 -08:00
zpool.c	mm/zswap: add the flag can_sleep_mapped	2021-02-26 09:41:01 -08:00
zsmalloc.c	mm/zsmalloc.c: use page_private() to access page->private	2021-02-26 09:41:01 -08:00
zswap.c	mm/zswap: add the flag can_sleep_mapped	2021-02-26 09:41:01 -08:00