Hugh Dickins 30acbabae3 mm: kill validate_anon_vma to avoid mapcount BUG ...

validate_anon_vma gave a useful check on the integrity of the anon_vma list
when Andrea was developing obj rmap; but it was not enabled in SLES9
itself, nor in mainline, until Nick changed commented-out RMAP_DEBUG to
configurable CONFIG_DEBUG_VM in 2.6.17.  Now Petr Vandrovec reports that
its BUG_ON(mapcount > 100000) can easily crash a CONFIG_DEBUG_VM=y system.

That limit was just an arbitrary number to protect against an infinite
loop.  We could raise it to something enormous (depending on sizeof struct
vma and size of memory?); but I rather think validate_anon_vma has outlived
its usefulness, and is better just removed - which gives a magnificent
performance boost to anything like Petr's test program ;)

Of course, a very long anon_vma list is bad news for preemption latency,
and I believe there has been one recent report of such: let's not forget
that, but validate_anon_vma only makes it worse not better.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Petr Vandrovec <petr@vmware.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Cc: Andrea Arcangeli <andrea@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2007-06-28 11:34:53 -07:00

..

allocpercpu.c

[PATCH] Allow NULL pointers in percpu_free

2006-12-07 08:39:22 -08:00

backing-dev.c

[PATCH] nfs: fix congestion control

2007-03-16 19:25:05 -07:00

bootmem.c

[PATCH] remove EXPORT_UNUSED_SYMBOL'ed symbols

2006-12-07 08:39:44 -08:00

bounce.c

block: blk_max_pfn is somtimes wrong

2007-03-27 08:52:47 +02:00

fadvise.c

[PATCH] mm: change uses of f_{dentry,vfsmnt} to use f_path

2006-12-08 08:28:43 -08:00

filemap_xip.c

Detach sched.h from mm.h

2007-05-21 09:18:19 -07:00

filemap.c

Fix: find_or_create_page skips cpuset memory spreading.

2007-05-16 21:19:15 -07:00

filemap.h

Remove all inclusions of <linux/config.h>

2006-10-04 03:38:54 -04:00

fremap.c

[PATCH] mm: more rmap debugging

2006-12-22 08:55:49 -08:00

highmem.c

[PATCH] i386: PARAVIRT: add kmap_atomic_pte for mapping highpte pages

2007-05-02 19:27:15 +02:00

hugetlb.c

Rework ptep_set_access_flags and fix sun4c

2007-06-16 13:16:16 -07:00

internal.h

Make page->private usable in compound pages

2007-05-07 12:12:53 -07:00

Kconfig

sh64: generic quicklist support.

2007-05-14 09:55:35 +09:00

madvise.c

Detach sched.h from mm.h

2007-05-21 09:18:19 -07:00

Makefile

Quicklists for page table pages

2007-05-07 12:12:54 -07:00

memory_hotplug.c

memory hotplug: fix unnecessary calling of init_currenty_empty_zone()

2007-06-01 08:18:29 -07:00

memory.c

Rework ptep_set_access_flags and fix sun4c

2007-06-16 13:16:16 -07:00

mempolicy.c

[PATCH] Page migration: Fix vma flag checking

2007-03-05 07:57:51 -08:00

mempool.c

[PATCH] Numerous fixes to kernel-doc info in source files.

2007-02-11 10:51:32 -08:00

migrate.c

page migration: fix NR_FILE_PAGES accounting

2007-04-24 08:23:08 -07:00

mincore.c

[PATCH] mincore: vma crossing fix

2007-02-15 09:57:03 -08:00

mlock.c

Detach sched.h from mm.h

2007-05-21 09:18:19 -07:00

mmap.c

[PARISC] Handle wrapping in expand_upwards()

2007-06-21 17:46:20 -04:00

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

Detach sched.h from mm.h

2007-05-21 09:18:19 -07:00

nommu.c

move die notifier handling to common code

2007-05-08 11:15:04 -07:00

oom_kill.c

oom: fix constraint deadlock

2007-05-07 12:12:55 -07:00

page_alloc.c

mm: Fix memory/cpu hotplug section mismatch and oops.

2007-06-15 16:18:08 -07:00

page_io.c

[PATCH] swsusp: use block device offsets to identify swap locations

2006-12-07 08:39:27 -08:00

page-writeback.c

consolidate generic_writepages and mpage_writepages

2007-05-11 08:29:35 -07:00

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

quicklist.c

Quicklists for page table pages

2007-05-07 12:12:54 -07:00

readahead.c

readahead: code cleanup

2007-05-07 12:12:52 -07:00

rmap.c

mm: kill validate_anon_vma to avoid mapcount BUG

2007-06-28 11:34:53 -07:00

shmem_acl.c

[PATCH] Fix typos in mm/shmem_acl.c

2006-10-11 11:14:23 -07:00

shmem.c

mount -t tmpfs -o mpol=: check nodes online

2007-06-08 17:23:32 -07:00

slab.c

slab: fix alien cache handling

2007-06-08 17:23:32 -07:00

slob.c

Remove SLAB_CTOR_CONSTRUCTOR

2007-05-17 05:23:04 -07:00

slub.c

SLUB: fix behavior if the text output of list_locations overflows PAGE_SIZE

2007-06-24 08:59:11 -07:00

sparse.c

Move three functions that are only needed for CONFIG_MEMORY_HOTPLUG

2007-06-08 17:23:33 -07:00

swap_state.c

[PATCH] lockdep: locking init debugging improvement

2006-07-03 15:27:02 -07:00

swap.c

Add suspend-related notifications for CPU hotplug

2007-05-09 12:30:56 -07:00

swapfile.c

mm: make read_cache_page synchronous

2007-05-07 12:12:51 -07:00

thrash.c

Bug in mm/thrash.c function grab_swap_token()

2007-05-11 08:29:32 -07:00

tiny-shmem.c

[PATCH] mm/{,tiny-}shmem.c cleanups

2007-03-01 14:53:35 -08:00

truncate.c

fs: convert core functions to zero_user_page

2007-05-09 12:30:55 -07:00

util.c

[PATCH] slab: clean up leak tracking ifdefs a little bit

2006-10-04 07:55:13 -07:00

vmalloc.c

Make __vunmap static

2007-05-17 05:23:04 -07:00

vmscan.c

Add suspend-related notifications for CPU hotplug

2007-05-09 12:30:56 -07:00

vmstat.c

Detach sched.h from mm.h

2007-05-21 09:18:19 -07:00