27 Jul, 2016
2 commits
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Randy reported below build error.
> In file included from ../include/linux/balloon_compaction.h:48:0,
> from ../mm/balloon_compaction.c:11:
> ../include/linux/compaction.h:237:51: warning: 'struct node' declared inside parameter list [enabled by default]
> static inline int compaction_register_node(struct node *node)
> ../include/linux/compaction.h:237:51: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default]
> ../include/linux/compaction.h:242:54: warning: 'struct node' declared inside parameter list [enabled by default]
> static inline void compaction_unregister_node(struct node *node)
>It was caused by non-lru page migration which needs compaction.h but
compaction.h doesn't include any header to be standalone.I think proper header for non-lru page migration is migrate.h rather
than compaction.h because migrate.h has already headers needed to work
non-lru page migration indirectly like isolate_mode_t, migrate_mode
MIGRATEPAGE_SUCCESS.[akpm@linux-foundation.org: revert mm-balloon-use-general-non-lru-movable-page-feature-fix.patch temp fix]
Link: http://lkml.kernel.org/r/20160610003304.GE29779@bbox
Signed-off-by: Minchan Kim
Reported-by: Randy Dunlap
Cc: Konstantin Khlebnikov
Cc: Vlastimil Babka
Cc: Gioh Kim
Cc: Rafael Aquini
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now, VM has a feature to migrate non-lru movable pages so balloon
doesn't need custom migration hooks in migrate.c and compaction.c.Instead, this patch implements the page->mapping->a_ops->
{isolate|migrate|putback} functions.With that, we could remove hooks for ballooning in general migration
functions and make balloon compaction simple.[akpm@linux-foundation.org: compaction.h requires that the includer first include node.h]
Link: http://lkml.kernel.org/r/1464736881-24886-4-git-send-email-minchan@kernel.org
Signed-off-by: Gioh Kim
Signed-off-by: Minchan Kim
Acked-by: Vlastimil Babka
Cc: Rafael Aquini
Cc: Konstantin Khlebnikov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Oct, 2014
3 commits
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Always mark pages with PageBalloon even if balloon compaction is disabled
and expose this mark in /proc/kpageflags as KPF_BALLOON.Also this patch adds three counters into /proc/vmstat: "balloon_inflate",
"balloon_deflate" and "balloon_migrate". They accumulate balloon
activity. Current size of balloon is (balloon_inflate - balloon_deflate)
pages.All generic balloon code now gathered under option CONFIG_MEMORY_BALLOON.
It should be selected by ballooning driver which wants use this feature.
Currently virtio-balloon is the only user.Signed-off-by: Konstantin Khlebnikov
Cc: Rafael Aquini
Cc: Andrey Ryabinin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now ballooned pages are detected using PageBalloon(). Fake mapping is no
longer required. This patch links ballooned pages to balloon device using
field page->private instead of page->mapping. Also this patch embeds
balloon_dev_info directly into struct virtio_balloon.Signed-off-by: Konstantin Khlebnikov
Cc: Rafael Aquini
Cc: Andrey Ryabinin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Sasha Levin reported KASAN splash inside isolate_migratepages_range().
Problem is in the function __is_movable_balloon_page() which tests
AS_BALLOON_MAP in page->mapping->flags. This function has no protection
against anonymous pages. As result it tried to check address space flags
inside struct anon_vma.Further investigation shows more problems in current implementation:
* Special branch in __unmap_and_move() never works:
balloon_page_movable() checks page flags and page_count. In
__unmap_and_move() page is locked, reference counter is elevated, thus
balloon_page_movable() always fails. As a result execution goes to the
normal migration path. virtballoon_migratepage() returns
MIGRATEPAGE_BALLOON_SUCCESS instead of MIGRATEPAGE_SUCCESS,
move_to_new_page() thinks this is an error code and assigns
newpage->mapping to NULL. Newly migrated page lose connectivity with
balloon an all ability for further migration.* lru_lock erroneously required in isolate_migratepages_range() for
isolation ballooned page. This function releases lru_lock periodically,
this makes migration mostly impossible for some pages.* balloon_page_dequeue have a tight race with balloon_page_isolate:
balloon_page_isolate could be executed in parallel with dequeue between
picking page from list and locking page_lock. Race is rare because they
use trylock_page() for locking.This patch fixes all of them.
Instead of fake mapping with special flag this patch uses special state of
page->_mapcount: PAGE_BALLOON_MAPCOUNT_VALUE = -256. Buddy allocator uses
PAGE_BUDDY_MAPCOUNT_VALUE = -128 for similar purpose. Storing mark
directly in struct page makes everything safer and easier.PagePrivate is used to mark pages present in page list (i.e. not
isolated, like PageLRU for normal pages). It replaces special rules for
reference counter and makes balloon migration similar to migration of
normal pages. This flag is protected by page_lock together with link to
the balloon device.Signed-off-by: Konstantin Khlebnikov
Reported-by: Sasha Levin
Link: http://lkml.kernel.org/p/53E6CEAA.9020105@oracle.com
Cc: Rafael Aquini
Cc: Andrey Ryabinin
Cc: [3.8+]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Oct, 2013
1 commit
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Isolated balloon pages can wrongly end up in LRU lists when
migrate_pages() finishes its round without draining all the isolated
page list.The same issue can happen when reclaim_clean_pages_from_list() tries to
reclaim pages from an isolated page list, before migration, in the CMA
path. Such balloon page leak opens a race window against LRU lists
shrinkers that leads us to the following kernel panic:BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
IP: [] shrink_page_list+0x24e/0x897
PGD 3cda2067 PUD 3d713067 PMD 0
Oops: 0000 [#1] SMP
CPU: 0 PID: 340 Comm: kswapd0 Not tainted 3.12.0-rc1-22626-g4367597 #87
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
RIP: shrink_page_list+0x24e/0x897
RSP: 0000:ffff88003da499b8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff88003e82bd60 RCX: 00000000000657d5
RDX: 0000000000000000 RSI: 000000000000031f RDI: ffff88003e82bd40
RBP: ffff88003da49ab0 R08: 0000000000000001 R09: 0000000081121a45
R10: ffffffff81121a45 R11: ffff88003c4a9a28 R12: ffff88003e82bd40
R13: ffff88003da0e800 R14: 0000000000000001 R15: ffff88003da49d58
FS: 0000000000000000(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000067d9000 CR3: 000000003ace5000 CR4: 00000000000407b0
Call Trace:
shrink_inactive_list+0x240/0x3de
shrink_lruvec+0x3e0/0x566
__shrink_zone+0x94/0x178
shrink_zone+0x3a/0x82
balance_pgdat+0x32a/0x4c2
kswapd+0x2f0/0x372
kthread+0xa2/0xaa
ret_from_fork+0x7c/0xb0
Code: 80 7d 8f 01 48 83 95 68 ff ff ff 00 4c 89 e7 e8 5a 7b 00 00 48 85 c0 49 89 c5 75 08 80 7d 8f 00 74 3e eb 31 48 8b 80 18 01 00 00 8b 74 0d 48 8b 78 30 be 02 00 00 00 ff d2 eb
RIP [] shrink_page_list+0x24e/0x897
RSP
CR2: 0000000000000028
---[ end trace 703d2451af6ffbfd ]---
Kernel panic - not syncing: Fatal exceptionThis patch fixes the issue, by assuring the proper tests are made at
putback_movable_pages() & reclaim_clean_pages_from_list() to avoid
isolated balloon pages being wrongly reinserted in LRU lists.[akpm@linux-foundation.org: clarify awkward comment text]
Signed-off-by: Rafael Aquini
Reported-by: Luiz Capitulino
Tested-by: Luiz Capitulino
Cc: Mel Gorman
Cc: Rik van Riel
Cc: Hugh Dickins
Cc: Johannes Weiner
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Dec, 2012
1 commit
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Memory fragmentation introduced by ballooning might reduce significantly
the number of 2MB contiguous memory blocks that can be used within a guest,
thus imposing performance penalties associated with the reduced number of
transparent huge pages that could be used by the guest workload.This patch introduces a common interface to help a balloon driver on
making its page set movable to compaction, and thus allowing the system
to better leverage the compation efforts on memory defragmentation.[akpm@linux-foundation.org: use PAGE_FLAGS_CHECK_AT_PREP, s/__balloon_page_flags/page_flags_cleared/, small cleanups]
[rientjes@google.com: allow balloon compaction for any system with memory compaction enabled, which is the defconfig]
Signed-off-by: Rafael Aquini
Acked-by: Mel Gorman
Cc: Rusty Russell
Cc: "Michael S. Tsirkin"
Cc: Rik van Riel
Cc: Andi Kleen
Cc: Konrad Rzeszutek Wilk
Cc: Minchan Kim
Signed-off-by: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds