12 Sep, 2013
1 commit
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Until now we can't offline memory blocks which contain hugepages because a
hugepage is considered as an unmovable page. But now with this patch
series, a hugepage has become movable, so by using hugepage migration we
can offline such memory blocks.What's different from other users of hugepage migration is that we need to
decompose all the hugepages inside the target memory block into free buddy
pages after hugepage migration, because otherwise free hugepages remaining
in the memory block intervene the memory offlining. For this reason we
introduce new functions dissolve_free_huge_page() and
dissolve_free_huge_pages().Other than that, what this patch does is straightforwardly to add hugepage
migration code, that is, adding hugepage code to the functions which scan
over pfn and collect hugepages to be migrated, and adding a hugepage
allocation function to alloc_migrate_target().As for larger hugepages (1GB for x86_64), it's not easy to do hotremove
over them because it's larger than memory block. So we now simply leave
it to fail as it is.[yongjun_wei@trendmicro.com.cn: remove duplicated include]
Signed-off-by: Naoya Horiguchi
Acked-by: Andi Kleen
Cc: Hillf Danton
Cc: Wanpeng Li
Cc: Mel Gorman
Cc: Hugh Dickins
Cc: KOSAKI Motohiro
Cc: Michal Hocko
Cc: Rik van Riel
Cc: "Aneesh Kumar K.V"
Signed-off-by: Wei Yongjun
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Aug, 2013
1 commit
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pageblock_nr_page should be pageblock_nr_pages, and fist is
a typo of first.Signed-off-by: Tang Chen
Signed-off-by: Jiri Kosina
05 Jan, 2013
1 commit
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Commit 702d1a6e0766 ("memory-hotplug: fix kswapd looping forever
problem") added an isolated pageblocks counter (nr_pageblock_isolate in
struct zone) and used it to adjust free pages counter in
zone_watermark_ok_safe() to prevent kswapd looping forever problem.Then later, commit 2139cbe627b8 ("cma: fix counting of isolated pages")
fixed accounting of isolated pages in global free pages counter. It
made the previous zone_watermark_ok_safe() fix unnecessary and
potentially harmful (cause now isolated pages may be accounted twice
making free pages counter incorrect).This patch removes the special isolated pageblocks counter altogether
which fixes zone_watermark_ok_safe() free pages check.Reported-by: Tomasz Stanislawski
Signed-off-by: Bartlomiej Zolnierkiewicz
Signed-off-by: Kyungmin Park
Cc: Minchan Kim
Cc: KOSAKI Motohiro
Cc: Aaditya Kumar
Cc: KAMEZAWA Hiroyuki
Cc: Mel Gorman
Cc: Michal Hocko
Cc: Marek Szyprowski
Cc: Michal Nazarewicz
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Dec, 2012
1 commit
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hwpoisoned may be set when we offline a page by the sysfs interface
/sys/devices/system/memory/soft_offline_page or
/sys/devices/system/memory/hard_offline_page. If we don't clear
this flag when onlining pages, this page can't be freed, and will
not in free list. So we can't offline these pages again. So we
should skip such page when offlining pages.Signed-off-by: Wen Congyang
Cc: David Rientjes
Cc: Jiang Liu
Cc: Len Brown
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Christoph Lameter
Cc: Minchan Kim
Cc: KOSAKI Motohiro
Cc: Yasuaki Ishimatsu
Cc: Andi Kleen
Cc: Mel Gorman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Oct, 2012
6 commits
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__alloc_contig_migrate_alloc() can be used by memory-hotplug so refactor
it out (move + rename as a common name) into page_isolation.c.[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Minchan Kim
Cc: Kamezawa Hiroyuki
Reviewed-by: Yasuaki Ishimatsu
Acked-by: Michal Nazarewicz
Cc: Marek Szyprowski
Cc: Wen Congyang
Acked-by: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If race between allocation and isolation in memory-hotplug offline
happens, some pages could be in MIGRATE_MOVABLE of free_list although the
pageblock's migratetype of the page is MIGRATE_ISOLATE.The race could be detected by get_freepage_migratetype in
__test_page_isolated_in_pageblock. If it is detected, now EBUSY gets
bubbled all the way up and the hotplug operations fails.But better idea is instead of returning and failing memory-hotremove, move
the free page to the correct list at the time it is detected. It could
enhance memory-hotremove operation success ratio although the race is
really rare.Suggested by Mel Gorman.
[akpm@linux-foundation.org: small cleanup]
Signed-off-by: Minchan Kim
Cc: KAMEZAWA Hiroyuki
Reviewed-by: Yasuaki Ishimatsu
Acked-by: Mel Gorman
Cc: Xishi Qiu
Cc: Wen Congyang
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Like below, memory-hotplug makes race between page-isolation
and page-allocation so it can hit BUG_ON in __offline_isolated_pages.CPU A CPU B
start_isolate_page_range
set_migratetype_isolate
spin_lock_irqsave(zone->lock)free_hot_cold_page(Page A)
/* without zone->lock */
migratetype = get_pageblock_migratetype(Page A);
/*
* Page could be moved into MIGRATE_MOVABLE
* of per_cpu_pages
*/
list_add_tail(&page->lru, &pcp->lists[migratetype]);set_pageblock_isolate
move_freepages_block
drain_all_pages/* Page A could be in MIGRATE_MOVABLE of free_list. */
check_pages_isolated
__test_page_isolated_in_pageblock
/*
* We can't catch freed page which
* is free_list[MIGRATE_MOVABLE]
*/
if (PageBuddy(page A))
pfn += 1 << page_order(page A);/* So, Page A could be allocated */
__offline_isolated_pages
/*
* BUG_ON hit or offline page
* which is used by someone
*/
BUG_ON(!PageBuddy(page A));This patch checks page's migratetype in freelist in
__test_page_isolated_in_pageblock. So now
__test_page_isolated_in_pageblock can check the page caused by above race
and can fail of memory offlining.Signed-off-by: Minchan Kim
Acked-by: KAMEZAWA Hiroyuki
Reviewed-by: Yasuaki Ishimatsu
Acked-by: Mel Gorman
Cc: Xishi Qiu
Cc: Wen Congyang
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The page allocator uses set_page_private and page_private for handling
migratetype when it frees page. Let's replace them with [set|get]
_freepage_migratetype to make it more clear.Signed-off-by: Minchan Kim
Acked-by: KAMEZAWA Hiroyuki
Reviewed-by: Yasuaki Ishimatsu
Acked-by: Mel Gorman
Cc: Xishi Qiu
Cc: Wen Congyang
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add NR_FREE_CMA_PAGES counter to be later used for checking watermark in
__zone_watermark_ok(). For simplicity and to avoid #ifdef hell make this
counter always available (not only when CONFIG_CMA=y).[akpm@linux-foundation.org: use conventional migratetype naming]
Signed-off-by: Bartlomiej Zolnierkiewicz
Signed-off-by: Kyungmin Park
Cc: Marek Szyprowski
Cc: Michal Nazarewicz
Cc: Minchan Kim
Cc: Mel Gorman
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Isolated free pages shouldn't be accounted to NR_FREE_PAGES counter. Fix
it by properly decreasing/increasing NR_FREE_PAGES counter in
set_migratetype_isolate()/unset_migratetype_isolate() and removing counter
adjustment for isolated pages from free_one_page() and split_free_page().Signed-off-by: Bartlomiej Zolnierkiewicz
Signed-off-by: Kyungmin Park
Cc: Marek Szyprowski
Cc: Michal Nazarewicz
Cc: Minchan Kim
Cc: Mel Gorman
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Aug, 2012
2 commits
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When hotplug offlining happens on zone A, it starts to mark freed page as
MIGRATE_ISOLATE type in buddy for preventing further allocation.
(MIGRATE_ISOLATE is very irony type because it's apparently on buddy but
we can't allocate them).When the memory shortage happens during hotplug offlining, current task
starts to reclaim, then wake up kswapd. Kswapd checks watermark, then go
sleep because current zone_watermark_ok_safe doesn't consider
MIGRATE_ISOLATE freed page count. Current task continue to reclaim in
direct reclaim path without kswapd's helping. The problem is that
zone->all_unreclaimable is set by only kswapd so that current task would
be looping forever like below.__alloc_pages_slowpath
restart:
wake_all_kswapd
rebalance:
__alloc_pages_direct_reclaim
do_try_to_free_pages
if global_reclaim && !all_unreclaimable
return 1; /* It means we did did_some_progress */
skip __alloc_pages_may_oom
should_alloc_retry
goto rebalance;If we apply KOSAKI's patch[1] which doesn't depends on kswapd about
setting zone->all_unreclaimable, we can solve this problem by killing some
task in direct reclaim path. But it doesn't wake up kswapd, still. It
could be a problem still if other subsystem needs GFP_ATOMIC request. So
kswapd should consider MIGRATE_ISOLATE when it calculate free pages BEFORE
going sleep.This patch counts the number of MIGRATE_ISOLATE page block and
zone_watermark_ok_safe will consider it if the system has such blocks
(fortunately, it's very rare so no problem in POV overhead and kswapd is
never hotpath).Copy/modify from Mel's quote
"
Ideal solution would be "allocating" the pageblock.
It would keep the free space accounting as it is but historically,
memory hotplug didn't allocate pages because it would be difficult to
detect if a pageblock was isolated or if part of some balloon.
Allocating just full pageblocks would work around this, However,
it would play very badly with CMA.
"[1] http://lkml.org/lkml/2012/6/14/74
[akpm@linux-foundation.org: simplify nr_zone_isolate_freepages(), rework zone_watermark_ok_safe() comment, simplify set_pageblock_isolate() and restore_pageblock_isolate()]
[akpm@linux-foundation.org: fix CONFIG_MEMORY_ISOLATION=n build]
Signed-off-by: Minchan Kim
Suggested-by: KOSAKI Motohiro
Tested-by: Aaditya Kumar
Cc: KAMEZAWA Hiroyuki
Cc: Mel Gorman
Cc: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
mm/page_alloc.c has some memory isolation functions but they are used only
when we enable CONFIG_{CMA|MEMORY_HOTPLUG|MEMORY_FAILURE}. So let's make
it configurable by new CONFIG_MEMORY_ISOLATION so that it can reduce
binary size and we can check it simple by CONFIG_MEMORY_ISOLATION, not if
defined CONFIG_{CMA|MEMORY_HOTPLUG|MEMORY_FAILURE}.Signed-off-by: Minchan Kim
Cc: Andi Kleen
Cc: Marek Szyprowski
Acked-by: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Cc: Mel Gorman
Cc: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 May, 2012
1 commit
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This commit changes various functions that change pages and
pageblocks migrate type between MIGRATE_ISOLATE and
MIGRATE_MOVABLE in such a way as to allow to work with
MIGRATE_CMA migrate type.Signed-off-by: Michal Nazarewicz
Signed-off-by: Marek Szyprowski
Reviewed-by: KAMEZAWA Hiroyuki
Tested-by: Rob Clark
Tested-by: Ohad Ben-Cohen
Tested-by: Benjamin Gaignard
Tested-by: Robert Nelson
Tested-by: Barry Song
27 Oct, 2010
1 commit
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__test_page_isolated_in_pageblock() returns 1 if all pages in the range
are isolated, so fix the comment. Variable `pfn' will be initialised in
the following loop so remove it.Signed-off-by: Bob Liu
Acked-by: KAMEZAWA Hiroyuki
Cc: Wu Fengguang
Cc: KOSAKI Motohiro
Cc: Mel Gorman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Nov, 2008
1 commit
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My last bugfix here (adding zone->lock) introduced a new problem: Using
page_zone(pfn_to_page(pfn)) to get the zone after the for() loop is wrong.
pfn will then be >= end_pfn, which may be in a different zone or not
present at all. This may lead to an addressing exception in page_zone()
or spin_lock_irqsave().Now I use __first_valid_page() again after the loop to find a valid page
for page_zone().Signed-off-by: Gerald Schaefer
Acked-by: Nathan Fontenot
Reviewed-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Oct, 2008
1 commit
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__test_page_isolated_in_pageblock() in mm/page_isolation.c has a comment
saying that the caller must hold zone->lock. But the only caller of that
function, test_pages_isolated(), does not hold zone->lock and the lock is
also not acquired anywhere before. This patch adds the missing zone->lock
to test_pages_isolated().We reproducibly run into BUG_ON(!PageBuddy(page)) in __offline_isolated_pages()
during memory hotplug stress test, see trace below. This patch fixes that
problem, it would be good if we could have it in 2.6.27.kernel BUG at /home/autobuild/BUILD/linux-2.6.26-20080909/mm/page_alloc.c:4561!
illegal operation: 0001 [#1] PREEMPT SMP
Modules linked in: dm_multipath sunrpc bonding qeth_l3 dm_mod qeth ccwgroup vmur
CPU: 1 Not tainted 2.6.26-29.x.20080909-s390default #1
Process memory_loop_all (pid: 10025, task: 2f444028, ksp: 2b10dd28)
Krnl PSW : 040c0000 801727ea (__offline_isolated_pages+0x18e/0x1c4)
R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:0 CC:0 PM:0
Krnl GPRS: 00000000 7e27fc00 00000000 7e27fc00
00000000 00000400 00014000 7e27fc01
00606f00 7e27fc00 00013fe0 2b10dd28
00000005 80172662 801727b2 2b10dd28
Krnl Code: 801727de: 5810900c l %r1,12(%r9)
801727e2: a7f4ffb3 brc 15,80172748
801727e6: a7f40001 brc 15,801727e8
>801727ea: a7f4ffbc brc 15,80172762
801727ee: a7f40001 brc 15,801727f0
801727f2: a7f4ffaf brc 15,80172750
801727f6: 0707 bcr 0,%r7
801727f8: 0017 unknown
Call Trace:
([] __offline_isolated_pages+0x116/0x1c4)
[] offline_isolated_pages_cb+0x22/0x34
[] walk_memory_resource+0xcc/0x11c
[] offline_pages+0x36a/0x498
[] remove_memory+0x36/0x44
[] memory_block_change_state+0x112/0x150
[] store_mem_state+0x90/0xe4
[] sysdev_store+0x34/0x40
[] sysfs_write_file+0xd0/0x178
[] vfs_write+0x74/0x118
[] sys_write+0x46/0x7c
[] sysc_do_restart+0x12/0x16
[] 0x77f3e8caSigned-off-by: Gerald Schaefer
Acked-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Sep, 2008
1 commit
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Signed-off-by: David Woodhouse
15 Nov, 2007
1 commit
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We should unset migrate type "ISOLATE" when we successfully removed memory.
But current code has BUG and cannot works well.This patch also includes bugfix? to change get_pageblock_flags to
get_pageblock_migratetype().Thanks to Badari Pulavarty for finding this.
Signed-off-by: KAMEZAWA Hiroyuki
Acked-by: Badari Pulavarty
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Oct, 2007
1 commit
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Implement generic chunk-of-pages isolation method by using page grouping ops.
This patch add MIGRATE_ISOLATE to MIGRATE_TYPES. By this
- MIGRATE_TYPES increases.
- bitmap for migratetype is enlarged.pages of MIGRATE_ISOLATE migratetype will not be allocated even if it is free.
By this, you can isolated *freed* pages from users. How-to-free pages is not
a purpose of this patch. You may use reclaim and migrate codes to free pages.If start_isolate_page_range(start,end) is called,
- migratetype of the range turns to be MIGRATE_ISOLATE if
its type is MIGRATE_MOVABLE. (*) this check can be updated if other
memory reclaiming works make progress.
- MIGRATE_ISOLATE is not on migratetype fallback list.
- All free pages and will-be-freed pages are isolated.
To check all pages in the range are isolated or not, use test_pages_isolated(),
To cancel isolation, use undo_isolate_page_range().Changes V6 -> V7
- removed unnecessary #ifdefThere are HOLES_IN_ZONE handling codes...I'm glad if we can remove them..
Signed-off-by: Yasunori Goto
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds