linux/mm
Ken Chen daa88c8d21 [PATCH] do not disturb page referenced state when unmapping memory range
When kernel unmaps an address range, it needs to transfer PTE state into
page struct.  Currently, kernel transfer access bit via
mark_page_accessed().  The call to mark_page_accessed in the unmap path
doesn't look logically correct.

At unmap time, calling mark_page_accessed will causes page LRU state to be
bumped up one step closer to more recently used state.  It is causing quite
a bit headache in a scenario when a process creates a shmem segment, touch
a whole bunch of pages, then unmaps it.  The unmapping takes a long time
because mark_page_accessed() will start moving pages from inactive to
active list.

I'm not too much concerned with moving the page from one list to another in
LRU.  Sooner or later it might be moved because of multiple mappings from
various processes.  But it just doesn't look logical that when user asks a
range to be unmapped, it's his intention that the process is no longer
interested in these pages.  Moving those pages to active list (or bumping
up a state towards more active) seems to be an over reaction.  It also
prolongs unmapping latency which is the core issue I'm trying to solve.

As suggested by Peter, we should still preserve the info on pte young
pages, but not more.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ken Chen <kenchen@google.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:19 -08:00
..
Kconfig [PATCH] Set CONFIG_ZONE_DMA for arches with GENERIC_ISA_DMA 2007-02-11 10:51:19 -08:00
Makefile [PATCH] separate bdi congestion functions from queue congestion functions 2006-10-20 10:26:35 -07:00
allocpercpu.c [PATCH] Allow NULL pointers in percpu_free 2006-12-07 08:39:22 -08:00
backing-dev.c [PATCH] separate bdi congestion functions from queue congestion functions 2006-10-20 10:26:35 -07:00
bootmem.c [PATCH] remove EXPORT_UNUSED_SYMBOL'ed symbols 2006-12-07 08:39:44 -08:00
bounce.c [PATCH] blktrace: only add a bounce trace when we really bounce 2007-01-12 10:46:49 -08:00
fadvise.c [PATCH] mm: change uses of f_{dentry,vfsmnt} to use f_path 2006-12-08 08:28:43 -08:00
filemap.c [PATCH] mm: remove find_trylock_page 2007-02-09 08:06:14 -08:00
filemap.h Remove all inclusions of <linux/config.h> 2006-10-04 03:38:54 -04:00
filemap_xip.c [PATCH] mm: mremap correct rmap accounting 2007-01-30 08:33:32 -08:00
fremap.c [PATCH] mm: more rmap debugging 2006-12-22 08:55:49 -08:00
highmem.c [PATCH] Use ZVC for free_pages 2007-02-11 10:51:17 -08:00
hugetlb.c [PATCH] hugetlb: preserve hugetlb pte dirty state 2007-02-09 09:25:46 -08:00
internal.h [PATCH] mm: VM_BUG_ON 2006-09-26 08:48:44 -07:00
madvise.c [PATCH] Fix MADV_REMOVE protection checking 2006-04-17 18:22:18 -07:00
memory.c [PATCH] do not disturb page referenced state when unmapping memory range 2007-02-11 10:51:19 -08:00
memory_hotplug.c [PATCH] Fix sparsemem on Cell 2007-01-11 18:18:20 -08:00
mempolicy.c [PATCH] optional ZONE_DMA: deal with cases of ZONE_DMA meaning the first zone 2007-02-11 10:51:18 -08:00
mempool.c [PATCH] dm: work around mempool_alloc, bio_alloc_bioset deadlocks 2006-09-01 11:39:09 -07:00
migrate.c [PATCH] radix-tree: RCU lockless readside 2006-12-07 08:39:25 -08:00
mincore.c [PATCH] sys_mincore: s/max/min/ 2006-12-17 10:21:53 -08:00
mlock.c [PATCH] mlock cleanup 2006-12-07 08:39:22 -08:00
mmap.c [PATCH] Add install_special_mapping 2007-02-09 09:25:47 -08:00
mmzone.c [PATCH] remove EXPORT_UNUSED_SYMBOL'ed symbols 2006-12-07 08:39:44 -08:00
mprotect.c [PATCH] paravirt: lazy mmu mode hooks.patch 2006-10-01 00:39:33 -07:00
mremap.c [PATCH] mm: mremap correct rmap accounting 2007-01-30 08:33:32 -08:00
msync.c [PATCH] mm: msync() cleanup 2006-09-26 08:48:45 -07:00
nommu.c [PATCH] struct path: convert mm 2006-12-08 08:28:47 -08:00
oom_kill.c [PATCH] fix OOM killing of swapoff 2007-01-05 23:55:29 -08:00
page-writeback.c [PATCH] simplify shmem_aops.set_page_dirty() method 2007-02-11 10:51:19 -08:00
page_alloc.c [PATCH] optional ZONE_DMA: optional ZONE_DMA in the VM 2007-02-11 10:51:18 -08:00
page_io.c [PATCH] swsusp: use block device offsets to identify swap locations 2006-12-07 08:39:27 -08:00
pdflush.c [PATCH] Add include/linux/freezer.h and move definitions from sched.h 2006-12-07 08:39:27 -08:00
prio_tree.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
readahead.c [PATCH] Drop __get_zone_counts() 2007-02-11 10:51:18 -08:00
rmap.c [PATCH] page_mkclean_one(): fix call to set_pte_at() 2006-12-30 10:56:42 -08:00
shmem.c [PATCH] simplify shmem_aops.set_page_dirty() method 2007-02-11 10:51:19 -08:00
shmem_acl.c [PATCH] Fix typos in mm/shmem_acl.c 2006-10-11 11:14:23 -07:00
slab.c [PATCH] optional ZONE_DMA: optional ZONE_DMA in the VM 2007-02-11 10:51:18 -08:00
slob.c [PATCH] MM: SLOB is broken by recent cleanup of slab.h 2006-12-30 10:56:42 -08:00
sparse.c [PATCH] numa node ids are int, page_to_nid and zone_to_nid should return int 2006-12-07 08:39:23 -08:00
swap.c [PATCH] hotplug CPU: clean up hotcpu_notifier() use 2006-12-07 08:39:39 -08:00
swap_state.c [PATCH] lockdep: locking init debugging improvement 2006-07-03 15:27:02 -07:00
swapfile.c [PATCH] swsusp: Do not fail if resume device is not set 2007-01-05 23:55:22 -08:00
thrash.c [PATCH] make mm/thrash.c:global_faults static 2006-12-07 08:39:22 -08:00
tiny-shmem.c [PATCH] struct path: convert mm 2006-12-08 08:28:47 -08:00
truncate.c [PATCH] MM: Remove [PATCH] invalidate_inode_pages2_range() debug 2007-01-26 13:51:00 -08:00
util.c [PATCH] slab: clean up leak tracking ifdefs a little bit 2006-10-04 07:55:13 -07:00
vmalloc.c [PATCH] Fix strange size check in __get_vm_area_node() 2006-11-16 11:43:38 -08:00
vmscan.c [PATCH] Use ZVC for inactive and active counts 2007-02-11 10:51:17 -08:00
vmstat.c [PATCH] optional ZONE_DMA: optional ZONE_DMA in the VM 2007-02-11 10:51:18 -08:00