KAMEZAWA Hiroyuki dc386d4d1e memory unplug: migration by kernel ... In usual, migrate_pages(page,,) is called with holding mm->sem by system call. (mm here is a mm_struct which maps the migration target page.) This semaphore helps avoiding some race conditions. But, if we want to migrate a page by some kernel codes, we have to avoid some races. This patch adds check code for following race condition. 1. A page which page->mapping==NULL can be target of migration. Then, we have to check page->mapping before calling try_to_unmap(). 2. anon_vma can be freed while page is unmapped, but page->mapping remains as it was. We drop page->mapcount to be 0. Then we cannot trust page->mapping. So, use rcu_read_lock() to prevent anon_vma pointed by page->mapping from being freed during migration. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2007-07-26 11:35:17 -07:00
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allocpercpu.c
backing-dev.c
bootmem.c
bounce.c
fadvise.c
filemap_xip.c
filemap.c
filemap.h
fremap.c
highmem.c
hugetlb.c
internal.h
Kconfig
madvise.c
Makefile
memory_hotplug.c
memory.c
mempolicy.c
mempool.c
migrate.c	memory unplug: migration by kernel	2007-07-26 11:35:17 -07:00
mincore.c
mlock.c
mmap.c
mmzone.c
mprotect.c
mremap.c
msync.c
nommu.c
oom_kill.c
page_alloc.c
page_io.c
page-writeback.c
pdflush.c
prio_tree.c
quicklist.c
readahead.c
rmap.c
shmem_acl.c
shmem.c
slab.c
slob.c
slub.c
sparse.c
swap_state.c
swap.c
swapfile.c
thrash.c
tiny-shmem.c
truncate.c
util.c
vmalloc.c
vmscan.c
vmstat.c