linux/mm
Serapheim Dimitropoulos f608788cd2 mm/vmalloc: use rb_tree instead of list for vread() lookups
vread() has been linearly searching vmap_area_list for looking up vmalloc
areas to read from.  These same areas are also tracked by a rb_tree
(vmap_area_root) which offers logarithmic lookup.

This patch modifies vread() to use the rb_tree structure instead of the
list and the speedup for heavy /proc/kcore readers can be pretty
significant.  Below are the wall clock measurements of a Python
application that leverages the drgn debugging library to read and
interpret data read from /proc/kcore.

Before the patch:
-----
  $ time sudo sdb -e 'dbuf | head 3000 | wc'
  (unsigned long)3000

  real	0m22.446s
  user	0m2.321s
  sys	0m20.690s
-----

With the patch:
-----
  $ time sudo sdb -e 'dbuf | head 3000 | wc'
  (unsigned long)3000

  real	0m2.104s
  user	0m2.043s
  sys	0m0.921s
-----

Link: https://lkml.kernel.org/r/20210209190253.108763-1-serapheim@delphix.com
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:39 -07:00
..
kasan arm64 updates for 5.13: 2021-04-26 10:25:03 -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
cma.c mm: cma: print region name on failure 2021-02-26 09:41:00 -08:00
cma.h mm: cma: use CMA_MAX_NAME to define the length of cma name array 2020-09-01 09:19:43 +02:00
compaction.c mm, compaction: make fast_isolate_freepages() stay within zone 2021-02-24 13:38:34 -08:00
debug_page_ref.c
debug_vm_pgtable.c mm/debug_vm_pgtable/basic: iterate over entire protection_map[] 2021-02-24 13:38:27 -08:00
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 mm/filemap: update stale comment 2021-04-30 11:20:37 -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/memcg: rename mem_cgroup_split_huge_fixup to split_page_memcg and add nr_pages argument 2021-03-13 11:27:31 -08:00
hugetlb_cgroup.c hugetlb_cgroup: fix imbalanced css_get and css_put pair for shared mappings 2021-03-25 09:22:55 -07:00
hugetlb.c hugetlb_cgroup: fix imbalanced css_get and css_put pair for shared mappings 2021-03-25 09:22:55 -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 Network filesystem helper library 2021-04-27 13:08:12 -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 p?d_alloc_track to separate header file 2020-08-07 11:33:26 -07:00
Kconfig mm: add a io_mapping_map_user helper 2021-04-30 11:20:39 -07:00
Kconfig.debug mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO 2020-12-15 12:13:46 -08:00
khugepaged.c mm,thp,shmem: make khugepaged obey tmpfs mount flags 2021-02-26 09:40:59 -08:00
kmemleak.c mm/kmemleak.c: fix a typo 2021-04-30 11:20:36 -07:00
ksm.c mm: cleanup kstrto*() usage 2020-12-15 12:13:47 -08:00
list_lru.c mm/list_lru.c: remove kvfree_rcu_local() 2021-02-24 13:38:30 -08:00
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: add a io_mapping_map_user helper 2021-04-30 11:20:39 -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: inline __memcg_kmem_{un}charge() into obj_cgroup_{un}charge_pages() 2021-04-30 11:20:38 -07:00
memfd.c
memory_hotplug.c arm64: mte: Map hotplugged memory as Normal Tagged 2021-03-10 10:56:46 +00:00
memory-failure.c mm: fix memory_failure() handling of dax-namespace metadata 2021-02-26 09:41:00 -08:00
memory.c NUMA balancing: reduce TLB flush via delaying mapping on hint page fault 2021-04-30 11:20:39 -07:00
mempolicy.c mm/mempolicy: use helper range_in_vma() in queue_pages_test_walk() 2021-02-24 13:38:34 -08:00
mempool.c kasan: move _RET_IP_ to inline wrappers 2021-02-24 13:38:31 -08:00
memremap.c mm/memremap.c: fix improper SPDX comment style 2021-04-30 11:20:37 -07:00
memtest.c
migrate.c mm: memcg: add swapcache stat for memcg v2 2021-02-24 13:38:29 -08:00
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 mm: fix fall-through warnings for Clang 2020-12-15 12:13:47 -08:00
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: memcontrol: directly access page->memcg_data in mm/page_alloc.c 2021-04-30 11:20:38 -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: memcg/percpu: account percpu memory to memory cgroups 2020-08-12 10:57:55 -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 Merge branch 'for-mingo-rcu' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu 2021-04-11 14:31:43 +02:00
slab.h RCU changes for this cycle were: 2021-04-28 12:00:13 -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 mm/slub.c: trivial typo fixes 2021-04-30 11:20:36 -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 memcg: charge before adding to swapcache on swapin 2021-04-30 11:20:38 -07:00
swap.c mm: remove pagevec_lookup_entries 2021-02-26 09:40:59 -08:00
swapfile.c swap: fix swapfile read/write offset 2021-03-02 17:25:46 -07:00
truncate.c mm: remove pagevec_lookup_entries 2021-02-26 09:40:59 -08:00
usercopy.c mm/usercopy.c: delete duplicated word 2020-08-12 10:57:58 -07:00
userfaultfd.c mm/vmscan: protect the workingset on anonymous LRU 2020-08-12 10:57:55 -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: use rb_tree instead of list for vread() lookups 2021-04-30 11:20:39 -07:00
vmpressure.c
vmscan.c mm/vmscan: restore zone_reclaim_mode ABI 2021-02-24 13:38:34 -08:00
vmstat.c mm/vmstat.c: erase latency in vmstat_shepherd 2021-02-26 09:41:00 -08:00
workingset.c mm: workingset: clarify eviction order and distance calculation 2021-02-24 13:38:34 -08:00
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