Hugh Dickins bc56620b49 ksm: shrink 32-bit rmap_item back to 32 bytes ... Think of struct rmap_item as an extension of struct page (restricted to MADV_MERGEABLE areas): there may be a lot of them, we need to keep them small, especially on 32-bit architectures of limited lowmem. Siting "int nid" after "unsigned int checksum" works nicely on 64-bit, making no change to its 64-byte struct rmap_item; but bloats the 32-bit struct rmap_item from (nicely cache-aligned) 32 bytes to 36 bytes, which rounds up to 40 bytes once allocated from slab. We'd better avoid that. Hey, I only just remembered that the anon_vma pointer in struct rmap_item has no purpose until the rmap_item is hung from a stable tree node (which has its own nid field); and rmap_item's nid field no purpose than to say which tree root to tell rb_erase() when unlinking from an unstable tree. Double them up in a union. There's just one place where we set anon_vma early (when we already hold mmap_sem): now we must remove tree_rmap_item from its unstable tree there, before overwriting nid. No need to spatter BUG()s around: we'd be seeing oopses if this were wrong. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Petr Holasek <pholasek@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Izik Eidus <izik.eidus@ravellosystems.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2013-02-23 17:50:23 -08:00
..
backing-dev.c	bdi: allow block devices to say that they require stable page writes	2013-02-21 17:22:19 -08:00
balloon_compaction.c	mm: introduce a common interface for balloon pages mobility	2012-12-11 17:22:26 -08:00
bootmem.c	mm: Add alloc_bootmem_low_pages_nopanic()	2013-01-29 19:32:59 -08:00
bounce.c	block: optionally snapshot page contents to provide stable pages during write	2013-02-21 17:22:20 -08:00
cleancache.c	->encode_fh() API change	2012-05-29 23:28:33 -04:00
compaction.c	mm: add & use zone_end_pfn() and zone_spans_pfn()	2013-02-23 17:50:20 -08:00
debug-pagealloc.c	mm, x86: Remove debug_pagealloc_enabled	2011-12-06 09:24:07 +01:00
dmapool.c	dmapool: make DMAPOOL_DEBUG detect corruption of free marker	2012-12-11 17:22:24 -08:00
fadvise.c	mm/fadvise.c: drain all pagevecs if POSIX_FADV_DONTNEED fails to discard all pages	2013-02-23 17:50:23 -08:00
failslab.c	switch debugfs to umode_t	2012-01-03 22:54:56 -05:00
filemap_xip.c	mm: move all mmu notifier invocations to be done outside the PT lock	2012-10-09 16:22:58 +09:00
filemap.c	mm: only enforce stable page writes if the backing device requires it	2013-02-21 17:22:19 -08:00
fremap.c	mm: introduce VM_POPULATE flag to better deal with racy userspace programs	2013-02-23 17:50:11 -08:00
frontswap.c	frontswap: support exclusive gets if tmem backend is capable	2012-09-21 10:38:12 -04:00
highmem.c	Some nice cleanups, and even a patch my wife did as a "live" demo for	2012-12-20 08:37:05 -08:00
huge_memory.c	mm: use NUMA_NO_NODE	2013-02-23 17:50:21 -08:00
hugetlb_cgroup.c	mm/hugetlb: create hugetlb cgroup file in hugetlb_init	2012-12-18 15:02:15 -08:00
hugetlb.c	mm: use long type for page counts in mm_populate() and get_user_pages()	2013-02-23 17:50:22 -08:00
hwpoison-inject.c	memcg: rename config variables	2012-07-31 18:42:43 -07:00
init-mm.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
internal.h	mm: directly use __mlock_vma_pages_range() in find_extend_vma()	2013-02-23 17:50:11 -08:00
interval_tree.c	mm: add CONFIG_DEBUG_VM_RB build option	2012-10-09 16:22:42 +09:00
Kconfig	memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmap	2013-02-23 17:50:12 -08:00
Kconfig.debug	mm: more intensive memory corruption debugging	2012-01-10 16:30:42 -08:00
kmemcheck.c
kmemleak-test.c	kmemleak: remove memset by using kzalloc	2011-01-27 18:31:51 +00:00
kmemleak.c	mm: add & use zone_end_pfn() and zone_spans_pfn()	2013-02-23 17:50:20 -08:00
ksm.c	ksm: shrink 32-bit rmap_item back to 32 bytes	2013-02-23 17:50:23 -08:00
maccess.c	mm: Map most files to use export.h instead of module.h	2011-10-31 09:20:12 -04:00
madvise.c	mm: make madvise(MADV_WILLNEED) support swap file prefetch	2013-02-23 17:50:10 -08:00
Makefile	mm: introduce a common interface for balloon pages mobility	2012-12-11 17:22:26 -08:00
memblock.c	mm/memblock.c: use CONFIG_HAVE_MEMBLOCK_NODE_MAP to protect movablecore_map in memblock_overlaps_region().	2013-02-23 17:50:14 -08:00
memcontrol.c	memcg: stop warning on memcg_propagate_kmem	2013-02-23 17:50:22 -08:00
memory_hotplug.c	mm/memory_hotplug: use pgdat_end_pfn() instead of open coding the same.	2013-02-23 17:50:21 -08:00
memory-failure.c	HWPOISON: change order of error_states[]'s elements	2013-02-23 17:50:22 -08:00
memory.c	mm: accelerate mm_populate() treatment of THP pages	2013-02-23 17:50:23 -08:00
mempolicy.c	mm: use NUMA_NO_NODE	2013-02-23 17:50:21 -08:00
mempool.c	mempool: add @gfp_mask to mempool_create_node()	2012-06-25 11:53:47 +02:00
migrate.c	mm: remove offlining arg to migrate_pages	2013-02-23 17:50:19 -08:00
mincore.c	swap: make each swap partition have one address_space	2013-02-23 17:50:17 -08:00
mlock.c	mm: use long type for page counts in mm_populate() and get_user_pages()	2013-02-23 17:50:22 -08:00
mm_init.c	mm: init: report on last-nid information stored in page->flags	2013-02-23 17:50:18 -08:00
mmap.c	mm/rmap: rename anon_vma_unlock() => anon_vma_unlock_write()	2013-02-23 17:50:17 -08:00
mmu_context.c	mm, counters: remove task argument to sync_mm_rss() and __sync_task_rss_stat()	2012-03-21 17:54:59 -07:00
mmu_notifier.c	mm: export mmu notifier invalidates	2013-02-23 17:50:23 -08:00
mmzone.c	mm: rename page struct field helpers	2013-02-23 17:50:18 -08:00
mprotect.c	mm/mprotect.c: coding-style cleanups	2012-12-18 15:02:15 -08:00
mremap.c	mm/rmap: rename anon_vma_unlock() => anon_vma_unlock_write()	2013-02-23 17:50:17 -08:00
msync.c
nobootmem.c	mm: Add alloc_bootmem_low_pages_nopanic()	2013-01-29 19:32:59 -08:00
nommu.c	mm: accelerate mm_populate() treatment of THP pages	2013-02-23 17:50:23 -08:00
oom_kill.c	memcg, oom: provide more precise dump info while memcg oom happening	2013-02-23 17:50:08 -08:00
page_alloc.c	mm: accurately document nr_free_*_pages functions with code comments	2013-02-23 17:50:22 -08:00
page_cgroup.c	memcontrol: use N_MEMORY instead N_HIGH_MEMORY	2012-12-12 17:38:32 -08:00
page_io.c	mm: add support for direct_IO to highmem pages	2012-07-31 18:42:47 -07:00
page_isolation.c	mm: fix zone_watermark_ok_safe() accounting of isolated pages	2013-01-04 16:11:46 -08:00
page-writeback.c	page-writeback.c: subtract min_free_kbytes from dirtyable memory	2013-02-23 17:50:17 -08:00
pagewalk.c	thp: change split_huge_page_pmd() interface	2012-12-12 17:38:31 -08:00
percpu-km.c
percpu-vm.c	mm: fix kernel-doc warnings	2012-06-20 14:39:36 -07:00
percpu.c	mm, percpu: Make sure percpu_alloc early parameter has an argument	2012-12-02 06:23:04 -08:00
pgtable-generic.c	mm: Only flush the TLB when clearing an accessible pte	2012-12-11 14:28:34 +00:00
process_vm_access.c	aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()	2012-05-31 17:49:32 -07:00
quicklist.c	mm: delete various needless include <linux/module.h>	2011-10-31 09:20:11 -04:00
readahead.c	switch simple cases of fget_light to fdget	2012-09-26 22:20:08 -04:00
rmap.c	mm/rmap: rename anon_vma_unlock() => anon_vma_unlock_write()	2013-02-23 17:50:17 -08:00
shmem.c	tmpfs: fix mempolicy object leaks	2013-02-23 17:50:23 -08:00
slab_common.c	slab: propagate tunable values	2012-12-18 15:02:14 -08:00
slab.c	memcg: add comments clarifying aspects of cache attribute propagation	2012-12-18 15:02:15 -08:00
slab.h	slab: propagate tunable values	2012-12-18 15:02:14 -08:00
slob.c	mm: rename page struct field helpers	2013-02-23 17:50:18 -08:00
slub.c	mm: rename page struct field helpers	2013-02-23 17:50:18 -08:00
sparse-vmemmap.c	mm: delete various needless include <linux/module.h>	2011-10-31 09:20:11 -04:00
sparse.c	memory-failure: use num_poisoned_pages instead of mce_bad_pages	2013-02-23 17:50:15 -08:00
swap_state.c	swap: add per-partition lock for swapfile	2013-02-23 17:50:17 -08:00
swap.c	swap: make each swap partition have one address_space	2013-02-23 17:50:17 -08:00
swapfile.c	swap: add per-partition lock for swapfile	2013-02-23 17:50:17 -08:00
truncate.c	mm: drop vmtruncate	2012-12-20 18:46:29 -05:00
util.c	swap: make each swap partition have one address_space	2013-02-23 17:50:17 -08:00
vmalloc.c	mm: use NUMA_NO_NODE	2013-02-23 17:50:21 -08:00
vmscan.c	vmscan: change type of vm_total_pages to unsigned long	2013-02-23 17:50:22 -08:00
vmstat.c	mm: add & use zone_end_pfn() and zone_spans_pfn()	2013-02-23 17:50:20 -08:00