From c406515239376fc93a30d5d03192182160cbd3fb Mon Sep 17 00:00:00 2001
From: Weijie Yang <weijie.yang@samsung.com>
Date: Thu, 13 Nov 2014 15:19:05 -0800
Subject: [PATCH 01/15] zram: avoid kunmap_atomic() of a NULL pointer
zram could kunmap_atomic() a NULL pointer in a rare situation: a zram
page becomes a full-zeroed page after a partial write io. The current
code doesn't handle this case and performs kunmap_atomic() on a NULL
pointer, which panics the kernel.
This patch fixes this issue.
Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Weijie Yang <weijie.yang.kh@gmail.com>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
drivers/block/zram/zram_drv.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 2ad0b5bce44b..3920ee45aa59 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -560,7 +560,8 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
}
if (page_zero_filled(uncmem)) {
- kunmap_atomic(user_mem);
+ if (user_mem)
+ kunmap_atomic(user_mem);
/* Free memory associated with this sector now. */
bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value);
zram_free_page(zram, index);
From 58420016303769f74c58248a59ca0f435041b352 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 13 Nov 2014 15:19:07 -0800
Subject: [PATCH 02/15] mm/compaction: skip the range until proper target
pageblock is met
Commit 7d49d8868336 ("mm, compaction: reduce zone checking frequency in
the migration scanner") has a side-effect that changes the iteration
range calculation. Before the change, block_end_pfn is calculated using
start_pfn, but now it blindly adds pageblock_nr_pages to the previous
value.
This causes the problem that isolation_start_pfn is larger than
block_end_pfn when we isolate the page with more than pageblock order.
In this case, isolation would fail due to an invalid range parameter.
To prevent this, this patch implements skipping the range until a proper
target pageblock is met. Without this patch, CMA with more than
pageblock order always fails but with this patch it will succeed.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/compaction.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/mm/compaction.c b/mm/compaction.c
index ec74cf0123ef..4f0151cfd238 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -479,6 +479,16 @@ isolate_freepages_range(struct compact_control *cc,
block_end_pfn = min(block_end_pfn, end_pfn);
+ /*
+ * pfn could pass the block_end_pfn if isolated freepage
+ * is more than pageblock order. In this case, we adjust
+ * scanning range to right one.
+ */
+ if (pfn >= block_end_pfn) {
+ block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages);
+ block_end_pfn = min(block_end_pfn, end_pfn);
+ }
+
if (!pageblock_pfn_to_page(pfn, block_end_pfn, cc->zone))
break;
From ad53f92eb416d81e469fa8ea57153e59455e7175 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 13 Nov 2014 15:19:11 -0800
Subject: [PATCH 03/15] mm/page_alloc: fix incorrect isolation behavior by
rechecking migratetype
Before describing bugs itself, I first explain definition of freepage.
1. pages on buddy list are counted as freepage.
2. pages on isolate migratetype buddy list are *not* counted as freepage.
3. pages on cma buddy list are counted as CMA freepage, too.
Now, I describe problems and related patch.
Patch 1: There is race conditions on getting pageblock migratetype that
it results in misplacement of freepages on buddy list, incorrect
freepage count and un-availability of freepage.
Patch 2: Freepages on pcp list could have stale cached information to
determine migratetype of buddy list to go. This causes misplacement of
freepages on buddy list and incorrect freepage count.
Patch 4: Merging between freepages on different migratetype of
pageblocks will cause freepages accouting problem. This patch fixes it.
Without patchset [3], above problem doesn't happens on my CMA allocation
test, because CMA reserved pages aren't used at all. So there is no
chance for above race.
With patchset [3], I did simple CMA allocation test and get below
result:
- Virtual machine, 4 cpus, 1024 MB memory, 256 MB CMA reservation
- run kernel build (make -j16) on background
- 30 times CMA allocation(8MB * 30 = 240MB) attempts in 5 sec interval
- Result: more than 5000 freepage count are missed
With patchset [3] and this patchset, I found that no freepage count are
missed so that I conclude that problems are solved.
On my simple memory offlining test, these problems also occur on that
environment, too.
This patch (of 4):
There are two paths to reach core free function of buddy allocator,
__free_one_page(), one is free_one_page()->__free_one_page() and the
other is free_hot_cold_page()->free_pcppages_bulk()->__free_one_page().
Each paths has race condition causing serious problems. At first, this
patch is focused on first type of freepath. And then, following patch
will solve the problem in second type of freepath.
In the first type of freepath, we got migratetype of freeing page
without holding the zone lock, so it could be racy. There are two cases
of this race.
1. pages are added to isolate buddy list after restoring orignal
migratetype
CPU1 CPU2
get migratetype => return MIGRATE_ISOLATE
call free_one_page() with MIGRATE_ISOLATE
grab the zone lock
unisolate pageblock
release the zone lock
grab the zone lock
call __free_one_page() with MIGRATE_ISOLATE
freepage go into isolate buddy list,
although pageblock is already unisolated
This may cause two problems. One is that we can't use this page anymore
until next isolation attempt of this pageblock, because freepage is on
isolate buddy list. The other is that freepage accouting could be wrong
due to merging between different buddy list. Freepages on isolate buddy
list aren't counted as freepage, but ones on normal buddy list are
counted as freepage. If merge happens, buddy freepage on normal buddy
list is inevitably moved to isolate buddy list without any consideration
of freepage accouting so it could be incorrect.
2. pages are added to normal buddy list while pageblock is isolated.
It is similar with above case.
This also may cause two problems. One is that we can't keep these
freepages from being allocated. Although this pageblock is isolated,
freepage would be added to normal buddy list so that it could be
allocated without any restriction. And the other problem is same as
case 1, that it, incorrect freepage accouting.
This race condition would be prevented by checking migratetype again
with holding the zone lock. Because it is somewhat heavy operation and
it isn't needed in common case, we want to avoid rechecking as much as
possible. So this patch introduce new variable, nr_isolate_pageblock in
struct zone to check if there is isolated pageblock. With this, we can
avoid to re-check migratetype in common case and do it only if there is
isolated pageblock or migratetype is MIGRATE_ISOLATE. This solve above
mentioned problems.
Changes from v3:
Add one more check in free_one_page() that checks whether migratetype is
MIGRATE_ISOLATE or not. Without this, abovementioned case 1 could happens.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Heesub Shin <heesub.shin@samsung.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Ritesh Harjani <ritesh.list@gmail.com>
Cc: Gioh Kim <gioh.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/mmzone.h | 9 +++++++++
include/linux/page-isolation.h | 8 ++++++++
mm/page_alloc.c | 11 +++++++++--
mm/page_isolation.c | 2 ++
4 files changed, 28 insertions(+), 2 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 48bf12ef6620..ffe66e381c04 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -431,6 +431,15 @@ struct zone {
*/
int nr_migrate_reserve_block;
+#ifdef CONFIG_MEMORY_ISOLATION
+ /*
+ * Number of isolated pageblock. It is used to solve incorrect
+ * freepage counting problem due to racy retrieving migratetype
+ * of pageblock. Protected by zone->lock.
+ */
+ unsigned long nr_isolate_pageblock;
+#endif
+
#ifdef CONFIG_MEMORY_HOTPLUG
/* see spanned/present_pages for more description */
seqlock_t span_seqlock;
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
index 3fff8e774067..2dc1e1697b45 100644
--- a/include/linux/page-isolation.h
+++ b/include/linux/page-isolation.h
@@ -2,6 +2,10 @@
#define __LINUX_PAGEISOLATION_H
#ifdef CONFIG_MEMORY_ISOLATION
+static inline bool has_isolate_pageblock(struct zone *zone)
+{
+ return zone->nr_isolate_pageblock;
+}
static inline bool is_migrate_isolate_page(struct page *page)
{
return get_pageblock_migratetype(page) == MIGRATE_ISOLATE;
@@ -11,6 +15,10 @@ static inline bool is_migrate_isolate(int migratetype)
return migratetype == MIGRATE_ISOLATE;
}
#else
+static inline bool has_isolate_pageblock(struct zone *zone)
+{
+ return false;
+}
static inline bool is_migrate_isolate_page(struct page *page)
{
return false;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9cd36b822444..df1da25b309b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -739,9 +739,16 @@ static void free_one_page(struct zone *zone,
if (nr_scanned)
__mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
+ if (unlikely(has_isolate_pageblock(zone) ||
+ is_migrate_isolate(migratetype))) {
+ migratetype = get_pfnblock_migratetype(page, pfn);
+ if (is_migrate_isolate(migratetype))
+ goto skip_counting;
+ }
+ __mod_zone_freepage_state(zone, 1 << order, migratetype);
+
+skip_counting:
__free_one_page(page, pfn, zone, order, migratetype);
- if (unlikely(!is_migrate_isolate(migratetype)))
- __mod_zone_freepage_state(zone, 1 << order, migratetype);
spin_unlock(&zone->lock);
}
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index d1473b2e9481..1fa4a4d72ecc 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -60,6 +60,7 @@ out:
int migratetype = get_pageblock_migratetype(page);
set_pageblock_migratetype(page, MIGRATE_ISOLATE);
+ zone->nr_isolate_pageblock++;
nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE);
__mod_zone_freepage_state(zone, -nr_pages, migratetype);
@@ -83,6 +84,7 @@ void unset_migratetype_isolate(struct page *page, unsigned migratetype)
nr_pages = move_freepages_block(zone, page, migratetype);
__mod_zone_freepage_state(zone, nr_pages, migratetype);
set_pageblock_migratetype(page, migratetype);
+ zone->nr_isolate_pageblock--;
out:
spin_unlock_irqrestore(&zone->lock, flags);
}
From 51bb1a4093cc68bc16b282548d9cee6104be0ef1 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 13 Nov 2014 15:19:14 -0800
Subject: [PATCH 04/15] mm/page_alloc: add freepage on isolate pageblock to
correct buddy list
In free_pcppages_bulk(), we use cached migratetype of freepage to
determine type of buddy list where freepage will be added. This
information is stored when freepage is added to pcp list, so if
isolation of pageblock of this freepage begins after storing, this
cached information could be stale. In other words, it has original
migratetype rather than MIGRATE_ISOLATE.
There are two problems caused by this stale information.
One is that we can't keep these freepages from being allocated.
Although this pageblock is isolated, freepage will be added to normal
buddy list so that it could be allocated without any restriction. And
the other problem is incorrect freepage accounting. Freepages on
isolate pageblock should not be counted for number of freepage.
Following is the code snippet in free_pcppages_bulk().
/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
__free_one_page(page, page_to_pfn(page), zone, 0, mt);
trace_mm_page_pcpu_drain(page, 0, mt);
if (likely(!is_migrate_isolate_page(page))) {
__mod_zone_page_state(zone, NR_FREE_PAGES, 1);
if (is_migrate_cma(mt))
__mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
}
As you can see above snippet, current code already handle second
problem, incorrect freepage accounting, by re-fetching pageblock
migratetype through is_migrate_isolate_page(page).
But, because this re-fetched information isn't used for
__free_one_page(), first problem would not be solved. This patch try to
solve this situation to re-fetch pageblock migratetype before
__free_one_page() and to use it for __free_one_page().
In addition to move up position of this re-fetch, this patch use
optimization technique, re-fetching migratetype only if there is isolate
pageblock. Pageblock isolation is rare event, so we can avoid
re-fetching in common case with this optimization.
This patch also correct migratetype of the tracepoint output.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Heesub Shin <heesub.shin@samsung.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Ritesh Harjani <ritesh.list@gmail.com>
Cc: Gioh Kim <gioh.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/page_alloc.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index df1da25b309b..58923bea0d8b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -715,14 +715,17 @@ static void free_pcppages_bulk(struct zone *zone, int count,
/* must delete as __free_one_page list manipulates */
list_del(&page->lru);
mt = get_freepage_migratetype(page);
+ if (unlikely(has_isolate_pageblock(zone))) {
+ mt = get_pageblock_migratetype(page);
+ if (is_migrate_isolate(mt))
+ goto skip_counting;
+ }
+ __mod_zone_freepage_state(zone, 1, mt);
+
+skip_counting:
/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
__free_one_page(page, page_to_pfn(page), zone, 0, mt);
trace_mm_page_pcpu_drain(page, 0, mt);
- if (likely(!is_migrate_isolate_page(page))) {
- __mod_zone_page_state(zone, NR_FREE_PAGES, 1);
- if (is_migrate_cma(mt))
- __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
- }
} while (--to_free && --batch_free && !list_empty(list));
}
spin_unlock(&zone->lock);
From 8f82b55dd558a74fc33d69a1f2c2605d0cd2c908 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 13 Nov 2014 15:19:18 -0800
Subject: [PATCH 05/15] mm/page_alloc: move freepage counting logic to
__free_one_page()
All the caller of __free_one_page() has similar freepage counting logic,
so we can move it to __free_one_page(). This reduce line of code and
help future maintenance.
This is also preparation step for "mm/page_alloc: restrict max order of
merging on isolated pageblock" which fix the freepage counting problem
on freepage with more than pageblock order.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Heesub Shin <heesub.shin@samsung.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Ritesh Harjani <ritesh.list@gmail.com>
Cc: Gioh Kim <gioh.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/page_alloc.c | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 58923bea0d8b..9f689f16b5aa 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -577,6 +577,8 @@ static inline void __free_one_page(struct page *page,
return;
VM_BUG_ON(migratetype == -1);
+ if (!is_migrate_isolate(migratetype))
+ __mod_zone_freepage_state(zone, 1 << order, migratetype);
page_idx = pfn & ((1 << MAX_ORDER) - 1);
@@ -715,14 +717,9 @@ static void free_pcppages_bulk(struct zone *zone, int count,
/* must delete as __free_one_page list manipulates */
list_del(&page->lru);
mt = get_freepage_migratetype(page);
- if (unlikely(has_isolate_pageblock(zone))) {
+ if (unlikely(has_isolate_pageblock(zone)))
mt = get_pageblock_migratetype(page);
- if (is_migrate_isolate(mt))
- goto skip_counting;
- }
- __mod_zone_freepage_state(zone, 1, mt);
-skip_counting:
/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
__free_one_page(page, page_to_pfn(page), zone, 0, mt);
trace_mm_page_pcpu_drain(page, 0, mt);
@@ -745,12 +742,7 @@ static void free_one_page(struct zone *zone,
if (unlikely(has_isolate_pageblock(zone) ||
is_migrate_isolate(migratetype))) {
migratetype = get_pfnblock_migratetype(page, pfn);
- if (is_migrate_isolate(migratetype))
- goto skip_counting;
}
- __mod_zone_freepage_state(zone, 1 << order, migratetype);
-
-skip_counting:
__free_one_page(page, pfn, zone, order, migratetype);
spin_unlock(&zone->lock);
}
From 3c605096d3158216ba9326a16266f6ba128c2c8d Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 13 Nov 2014 15:19:21 -0800
Subject: [PATCH 06/15] mm/page_alloc: restrict max order of merging on
isolated pageblock
Current pageblock isolation logic could isolate each pageblock
individually. This causes freepage accounting problem if freepage with
pageblock order on isolate pageblock is merged with other freepage on
normal pageblock. We can prevent merging by restricting max order of
merging to pageblock order if freepage is on isolate pageblock.
A side-effect of this change is that there could be non-merged buddy
freepage even if finishing pageblock isolation, because undoing
pageblock isolation is just to move freepage from isolate buddy list to
normal buddy list rather than to consider merging. So, the patch also
makes undoing pageblock isolation consider freepage merge. When
un-isolation, freepage with more than pageblock order and it's buddy are
checked. If they are on normal pageblock, instead of just moving, we
isolate the freepage and free it in order to get merged.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Heesub Shin <heesub.shin@samsung.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Ritesh Harjani <ritesh.list@gmail.com>
Cc: Gioh Kim <gioh.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/internal.h | 25 +++++++++++++++++++++++++
mm/page_alloc.c | 41 ++++++++++++++---------------------------
mm/page_isolation.c | 41 +++++++++++++++++++++++++++++++++++++++--
3 files changed, 78 insertions(+), 29 deletions(-)
diff --git a/mm/internal.h b/mm/internal.h
index 829304090b90..a4f90ba7068e 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -108,6 +108,31 @@ extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
/*
* in mm/page_alloc.c
*/
+
+/*
+ * Locate the struct page for both the matching buddy in our
+ * pair (buddy1) and the combined O(n+1) page they form (page).
+ *
+ * 1) Any buddy B1 will have an order O twin B2 which satisfies
+ * the following equation:
+ * B2 = B1 ^ (1 << O)
+ * For example, if the starting buddy (buddy2) is #8 its order
+ * 1 buddy is #10:
+ * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
+ *
+ * 2) Any buddy B will have an order O+1 parent P which
+ * satisfies the following equation:
+ * P = B & ~(1 << O)
+ *
+ * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
+ */
+static inline unsigned long
+__find_buddy_index(unsigned long page_idx, unsigned int order)
+{
+ return page_idx ^ (1 << order);
+}
+
+extern int __isolate_free_page(struct page *page, unsigned int order);
extern void __free_pages_bootmem(struct page *page, unsigned int order);
extern void prep_compound_page(struct page *page, unsigned long order);
#ifdef CONFIG_MEMORY_FAILURE
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9f689f16b5aa..fd11b913779e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -466,29 +466,6 @@ static inline void rmv_page_order(struct page *page)
set_page_private(page, 0);
}
-/*
- * Locate the struct page for both the matching buddy in our
- * pair (buddy1) and the combined O(n+1) page they form (page).
- *
- * 1) Any buddy B1 will have an order O twin B2 which satisfies
- * the following equation:
- * B2 = B1 ^ (1 << O)
- * For example, if the starting buddy (buddy2) is #8 its order
- * 1 buddy is #10:
- * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
- *
- * 2) Any buddy B will have an order O+1 parent P which
- * satisfies the following equation:
- * P = B & ~(1 << O)
- *
- * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
- */
-static inline unsigned long
-__find_buddy_index(unsigned long page_idx, unsigned int order)
-{
- return page_idx ^ (1 << order);
-}
-
/*
* This function checks whether a page is free && is the buddy
* we can do coalesce a page and its buddy if
@@ -569,6 +546,7 @@ static inline void __free_one_page(struct page *page,
unsigned long combined_idx;
unsigned long uninitialized_var(buddy_idx);
struct page *buddy;
+ int max_order = MAX_ORDER;
VM_BUG_ON(!zone_is_initialized(zone));
@@ -577,15 +555,24 @@ static inline void __free_one_page(struct page *page,
return;
VM_BUG_ON(migratetype == -1);
- if (!is_migrate_isolate(migratetype))
+ if (is_migrate_isolate(migratetype)) {
+ /*
+ * We restrict max order of merging to prevent merge
+ * between freepages on isolate pageblock and normal
+ * pageblock. Without this, pageblock isolation
+ * could cause incorrect freepage accounting.
+ */
+ max_order = min(MAX_ORDER, pageblock_order + 1);
+ } else {
__mod_zone_freepage_state(zone, 1 << order, migratetype);
+ }
- page_idx = pfn & ((1 << MAX_ORDER) - 1);
+ page_idx = pfn & ((1 << max_order) - 1);
VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page);
VM_BUG_ON_PAGE(bad_range(zone, page), page);
- while (order < MAX_ORDER-1) {
+ while (order < max_order - 1) {
buddy_idx = __find_buddy_index(page_idx, order);
buddy = page + (buddy_idx - page_idx);
if (!page_is_buddy(page, buddy, order))
@@ -1486,7 +1473,7 @@ void split_page(struct page *page, unsigned int order)
}
EXPORT_SYMBOL_GPL(split_page);
-static int __isolate_free_page(struct page *page, unsigned int order)
+int __isolate_free_page(struct page *page, unsigned int order)
{
unsigned long watermark;
struct zone *zone;
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 1fa4a4d72ecc..c8778f7e208e 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -76,17 +76,54 @@ void unset_migratetype_isolate(struct page *page, unsigned migratetype)
{
struct zone *zone;
unsigned long flags, nr_pages;
+ struct page *isolated_page = NULL;
+ unsigned int order;
+ unsigned long page_idx, buddy_idx;
+ struct page *buddy;
zone = page_zone(page);
spin_lock_irqsave(&zone->lock, flags);
if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
goto out;
- nr_pages = move_freepages_block(zone, page, migratetype);
- __mod_zone_freepage_state(zone, nr_pages, migratetype);
+
+ /*
+ * Because freepage with more than pageblock_order on isolated
+ * pageblock is restricted to merge due to freepage counting problem,
+ * it is possible that there is free buddy page.
+ * move_freepages_block() doesn't care of merge so we need other
+ * approach in order to merge them. Isolation and free will make
+ * these pages to be merged.
+ */
+ if (PageBuddy(page)) {
+ order = page_order(page);
+ if (order >= pageblock_order) {
+ page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
+ buddy_idx = __find_buddy_index(page_idx, order);
+ buddy = page + (buddy_idx - page_idx);
+
+ if (!is_migrate_isolate_page(buddy)) {
+ __isolate_free_page(page, order);
+ set_page_refcounted(page);
+ isolated_page = page;
+ }
+ }
+ }
+
+ /*
+ * If we isolate freepage with more than pageblock_order, there
+ * should be no freepage in the range, so we could avoid costly
+ * pageblock scanning for freepage moving.
+ */
+ if (!isolated_page) {
+ nr_pages = move_freepages_block(zone, page, migratetype);
+ __mod_zone_freepage_state(zone, nr_pages, migratetype);
+ }
set_pageblock_migratetype(page, migratetype);
zone->nr_isolate_pageblock--;
out:
spin_unlock_irqrestore(&zone->lock, flags);
+ if (isolated_page)
+ __free_pages(isolated_page, order);
}
static inline struct page *
From 95069ac8da4975120ba76e968fc72948582c3509 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 13 Nov 2014 15:19:25 -0800
Subject: [PATCH 07/15] mm/slab: fix unalignment problem on Malta with EVA due
to slab merge
Unlike SLUB, sometimes, object isn't started at the beginning of the
slab in SLAB. This causes the unalignment problem after slab merging is
supported by commit 12220dea07f1 ("mm/slab: support slab merge").
Following is the report from Markos that fail to boot on Malta with EVA.
Calibrating delay loop... 19.86 BogoMIPS (lpj=99328)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 4096 (order: 0, 16384 bytes)
Mountpoint-cache hash table entries: 4096 (order: 0, 16384 bytes)
Kernel bug detected[#1]:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.17.0-05639-g12220dea07f1 #1631
task: 1f04f5d8 ti: 1f050000 task.ti: 1f050000
epc : 80141190 alloc_unbound_pwq+0x234/0x304
Not tainted
ra : 80141184 alloc_unbound_pwq+0x228/0x304
Process swapper/0 (pid: 1, threadinfo=1f050000, task=1f04f5d8, tls=00000000)
Call Trace:
alloc_unbound_pwq+0x234/0x304
apply_workqueue_attrs+0x11c/0x294
__alloc_workqueue_key+0x23c/0x470
init_workqueues+0x320/0x400
do_one_initcall+0xe8/0x23c
kernel_init_freeable+0x9c/0x224
kernel_init+0x10/0x100
ret_from_kernel_thread+0x14/0x1c
[ end trace cb88537fdc8fa200 ]
Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
alloc_unbound_pwq() allocates slab object from pool_workqueue. This
kmem_cache requires 256 bytes alignment, but, current merging code
doesn't honor that, and merge it with kmalloc-256. kmalloc-256 requires
only cacheline size alignment so that above failure occurs. However, in
x86, kmalloc-256 is luckily aligned in 256 bytes, so the problem didn't
happen on it.
To fix this problem, this patch introduces alignment mismatch check in
find_mergeable(). This will fix the problem.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reported-by: Markos Chandras <Markos.Chandras@imgtec.com>
Tested-by: Markos Chandras <Markos.Chandras@imgtec.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/slab_common.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 406944207b61..dcdab81bd240 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -259,6 +259,10 @@ struct kmem_cache *find_mergeable(size_t size, size_t align,
if (s->size - size >= sizeof(void *))
continue;
+ if (IS_ENABLED(CONFIG_SLAB) && align &&
+ (align > s->align || s->align % align))
+ continue;
+
return s;
}
return NULL;
From dae803e165a11bc88ca8dbc07a11077caf97bbcb Mon Sep 17 00:00:00 2001
From: Michal Nazarewicz <mina86@mina86.com>
Date: Thu, 13 Nov 2014 15:19:27 -0800
Subject: [PATCH 08/15] mm: alloc_contig_range: demote pages busy message from
warn to info
Having test_pages_isolated failure message as a warning confuses users
into thinking that it is more serious than it really is. In reality, if
called via CMA, allocation will be retried so a single
test_pages_isolated failure does not prevent allocation from succeeding.
Demote the warning message to an info message and reformat it such that
the text "failed" does not appear and instead a less worrying "PFNS
busy" is used.
This message is trivially reproducible on a 10GB x86 machine on 3.16.y
kernels configured with CONFIG_DMA_CMA.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/page_alloc.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index fd11b913779e..181dc593962b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6397,13 +6397,12 @@ int alloc_contig_range(unsigned long start, unsigned long end,
/* Make sure the range is really isolated. */
if (test_pages_isolated(outer_start, end, false)) {
- pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
- outer_start, end);
+ pr_info("%s: [%lx, %lx) PFNs busy\n",
+ __func__, outer_start, end);
ret = -EBUSY;
goto done;
}
-
/* Grab isolated pages from freelists. */
outer_end = isolate_freepages_range(&cc, outer_start, end);
if (!outer_end) {
From 1d5bfe1ffb5b9014ea80bcd8a40ae43a3e213120 Mon Sep 17 00:00:00 2001
From: Vlastimil Babka <vbabka@suse.cz>
Date: Thu, 13 Nov 2014 15:19:30 -0800
Subject: [PATCH 09/15] mm, compaction: prevent infinite loop in compact_zone
Several people have reported occasionally seeing processes stuck in
compact_zone(), even triggering soft lockups, in 3.18-rc2+.
Testing a revert of commit e14c720efdd7 ("mm, compaction: remember
position within pageblock in free pages scanner") fixed the issue,
although the stuck processes do not appear to involve the free scanner.
Finally, by code inspection, the bug was found in isolate_migratepages()
which uses a slightly different condition to detect if the migration and
free scanners have met, than compact_finished(). That has not been a
problem until commit e14c720efdd7 allowed the free scanner position
between individual invocations to be in the middle of a pageblock.
In a relatively rare case, the migration scanner position can end up at
the beginning of a pageblock, with the free scanner position in the
middle of the same pageblock. If it's the migration scanner's turn,
isolate_migratepages() exits immediately (without updating the
position), while compact_finished() decides to continue compaction,
resulting in a potentially infinite loop. The system can recover only
if another process creates enough high-order pages to make the watermark
checks in compact_finished() pass.
This patch fixes the immediate problem by bumping the migration
scanner's position to meet the free scanner in isolate_migratepages(),
when both are within the same pageblock. This causes compact_finished()
to terminate properly. A more robust check in compact_finished() is
planned as a cleanup for better future maintainability.
Fixes: e14c720efdd73 ("mm, compaction: remember position within pageblock in free pages scanner)
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: P. Christeas <xrg@linux.gr>
Tested-by: P. Christeas <xrg@linux.gr>
Link: http://marc.info/?l=linux-mm&m=141508604232522&w=2
Reported-by: Norbert Preining <preining@logic.at>
Tested-by: Norbert Preining <preining@logic.at>
Link: https://lkml.org/lkml/2014/11/4/904
Reported-by: Pavel Machek <pavel@ucw.cz>
Link: https://lkml.org/lkml/2014/11/7/164
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/compaction.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/mm/compaction.c b/mm/compaction.c
index 4f0151cfd238..f9792ba3537c 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1039,8 +1039,12 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
}
acct_isolated(zone, cc);
- /* Record where migration scanner will be restarted */
- cc->migrate_pfn = low_pfn;
+ /*
+ * Record where migration scanner will be restarted. If we end up in
+ * the same pageblock as the free scanner, make the scanners fully
+ * meet so that compact_finished() terminates compaction.
+ */
+ cc->migrate_pfn = (end_pfn <= cc->free_pfn) ? low_pfn : cc->free_pfn;
return cc->nr_migratepages ? ISOLATE_SUCCESS : ISOLATE_NONE;
}
From 8edc6e1688fc8f02c8c1f53a2ec4928cb1055f4d Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Thu, 13 Nov 2014 15:19:33 -0800
Subject: [PATCH 10/15] fanotify: fix notification of groups with inode & mount
marks
fsnotify() needs to merge inode and mount marks lists when notifying
groups about events so that ignore masks from inode marks are reflected
in mount mark notifications and groups are notified in proper order
(according to priorities).
Currently the sorting of the lists done by fsnotify_add_inode_mark() /
fsnotify_add_vfsmount_mark() and fsnotify() differed which resulted
ignore masks not being used in some cases.
Fix the problem by always using the same comparison function when
sorting / merging the mark lists.
Thanks to Heinrich Schuchardt for improvements of my patch.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=87721
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/notify/fsnotify.c | 36 +++++++++++++++++++++---------------
fs/notify/fsnotify.h | 4 ++++
fs/notify/inode_mark.c | 8 +++-----
fs/notify/mark.c | 36 ++++++++++++++++++++++++++++++++++++
fs/notify/vfsmount_mark.c | 8 +++-----
5 files changed, 67 insertions(+), 25 deletions(-)
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 9d3e9c50066a..89326acd4561 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -229,8 +229,16 @@ int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
&fsnotify_mark_srcu);
}
+ /*
+ * We need to merge inode & vfsmount mark lists so that inode mark
+ * ignore masks are properly reflected for mount mark notifications.
+ * That's why this traversal is so complicated...
+ */
while (inode_node || vfsmount_node) {
- inode_group = vfsmount_group = NULL;
+ inode_group = NULL;
+ inode_mark = NULL;
+ vfsmount_group = NULL;
+ vfsmount_mark = NULL;
if (inode_node) {
inode_mark = hlist_entry(srcu_dereference(inode_node, &fsnotify_mark_srcu),
@@ -244,21 +252,19 @@ int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
vfsmount_group = vfsmount_mark->group;
}
- if (inode_group > vfsmount_group) {
- /* handle inode */
- ret = send_to_group(to_tell, inode_mark, NULL, mask,
- data, data_is, cookie, file_name);
- /* we didn't use the vfsmount_mark */
- vfsmount_group = NULL;
- } else if (vfsmount_group > inode_group) {
- ret = send_to_group(to_tell, NULL, vfsmount_mark, mask,
- data, data_is, cookie, file_name);
- inode_group = NULL;
- } else {
- ret = send_to_group(to_tell, inode_mark, vfsmount_mark,
- mask, data, data_is, cookie,
- file_name);
+ if (inode_group && vfsmount_group) {
+ int cmp = fsnotify_compare_groups(inode_group,
+ vfsmount_group);
+ if (cmp > 0) {
+ inode_group = NULL;
+ inode_mark = NULL;
+ } else if (cmp < 0) {
+ vfsmount_group = NULL;
+ vfsmount_mark = NULL;
+ }
}
+ ret = send_to_group(to_tell, inode_mark, vfsmount_mark, mask,
+ data, data_is, cookie, file_name);
if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
goto out;
diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h
index 9c0898c4cfe1..3b68b0ae0a97 100644
--- a/fs/notify/fsnotify.h
+++ b/fs/notify/fsnotify.h
@@ -12,6 +12,10 @@ extern void fsnotify_flush_notify(struct fsnotify_group *group);
/* protects reads of inode and vfsmount marks list */
extern struct srcu_struct fsnotify_mark_srcu;
+/* compare two groups for sorting of marks lists */
+extern int fsnotify_compare_groups(struct fsnotify_group *a,
+ struct fsnotify_group *b);
+
extern void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *fsn_mark,
__u32 mask);
/* add a mark to an inode */
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index e8497144b323..dfbf5447eea4 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -194,6 +194,7 @@ int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
{
struct fsnotify_mark *lmark, *last = NULL;
int ret = 0;
+ int cmp;
mark->flags |= FSNOTIFY_MARK_FLAG_INODE;
@@ -219,11 +220,8 @@ int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
goto out;
}
- if (mark->group->priority < lmark->group->priority)
- continue;
-
- if ((mark->group->priority == lmark->group->priority) &&
- (mark->group < lmark->group))
+ cmp = fsnotify_compare_groups(lmark->group, mark->group);
+ if (cmp < 0)
continue;
hlist_add_before_rcu(&mark->i.i_list, &lmark->i.i_list);
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index d90deaa08e78..34c38fabf514 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -209,6 +209,42 @@ void fsnotify_set_mark_ignored_mask_locked(struct fsnotify_mark *mark, __u32 mas
mark->ignored_mask = mask;
}
+/*
+ * Sorting function for lists of fsnotify marks.
+ *
+ * Fanotify supports different notification classes (reflected as priority of
+ * notification group). Events shall be passed to notification groups in
+ * decreasing priority order. To achieve this marks in notification lists for
+ * inodes and vfsmounts are sorted so that priorities of corresponding groups
+ * are descending.
+ *
+ * Furthermore correct handling of the ignore mask requires processing inode
+ * and vfsmount marks of each group together. Using the group address as
+ * further sort criterion provides a unique sorting order and thus we can
+ * merge inode and vfsmount lists of marks in linear time and find groups
+ * present in both lists.
+ *
+ * A return value of 1 signifies that b has priority over a.
+ * A return value of 0 signifies that the two marks have to be handled together.
+ * A return value of -1 signifies that a has priority over b.
+ */
+int fsnotify_compare_groups(struct fsnotify_group *a, struct fsnotify_group *b)
+{
+ if (a == b)
+ return 0;
+ if (!a)
+ return 1;
+ if (!b)
+ return -1;
+ if (a->priority < b->priority)
+ return 1;
+ if (a->priority > b->priority)
+ return -1;
+ if (a < b)
+ return 1;
+ return -1;
+}
+
/*
* Attach an initialized mark to a given group and fs object.
* These marks may be used for the fsnotify backend to determine which
diff --git a/fs/notify/vfsmount_mark.c b/fs/notify/vfsmount_mark.c
index ac851e8376b1..faefa72a11eb 100644
--- a/fs/notify/vfsmount_mark.c
+++ b/fs/notify/vfsmount_mark.c
@@ -153,6 +153,7 @@ int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
struct mount *m = real_mount(mnt);
struct fsnotify_mark *lmark, *last = NULL;
int ret = 0;
+ int cmp;
mark->flags |= FSNOTIFY_MARK_FLAG_VFSMOUNT;
@@ -178,11 +179,8 @@ int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
goto out;
}
- if (mark->group->priority < lmark->group->priority)
- continue;
-
- if ((mark->group->priority == lmark->group->priority) &&
- (mark->group < lmark->group))
+ cmp = fsnotify_compare_groups(lmark->group, mark->group);
+ if (cmp < 0)
continue;
hlist_add_before_rcu(&mark->m.m_list, &lmark->m.m_list);
From 57cbc87e03c2f473d8f0579186c078ee06f48f2c Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 13 Nov 2014 15:19:36 -0800
Subject: [PATCH 11/15] mm/debug-pagealloc: correct freepage accounting and
order resetting
One thing I did in this patch is fixing freepage accounting. If we
clear guard page and link it onto isolate buddy list, we should not
increase freepage count. This patch adds conditional branch to skip
counting in this case. Without this patch, this overcounting happens
frequently if guard order is set and CMA is used.
Another thing fixed in this patch is the target to reset order. In
__free_one_page(), we check the buddy page whether it is a guard page or
not. And, if so, we should clear guard attribute on the buddy page and
reset order of it to 0. But, current code resets original page's order
rather than buddy one's. Maybe, this doesn't have any problem, because
whole merged page's order will be re-assigned soon. But, it is better
to correct code.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Gioh Kim <gioh.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/page_alloc.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 181dc593962b..616a2c956b4b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -583,9 +583,11 @@ static inline void __free_one_page(struct page *page,
*/
if (page_is_guard(buddy)) {
clear_page_guard_flag(buddy);
- set_page_private(page, 0);
- __mod_zone_freepage_state(zone, 1 << order,
- migratetype);
+ set_page_private(buddy, 0);
+ if (!is_migrate_isolate(migratetype)) {
+ __mod_zone_freepage_state(zone, 1 << order,
+ migratetype);
+ }
} else {
list_del(&buddy->lru);
zone->free_area[order].nr_free--;
From f784a3f19613901ca4539a5b0eed3bdc700e6ee7 Mon Sep 17 00:00:00 2001
From: Tang Chen <tangchen@cn.fujitsu.com>
Date: Thu, 13 Nov 2014 15:19:39 -0800
Subject: [PATCH 12/15] mem-hotplug: reset node managed pages when hot-adding a
new pgdat
In free_area_init_core(), zone->managed_pages is set to an approximate
value for lowmem, and will be adjusted when the bootmem allocator frees
pages into the buddy system.
But free_area_init_core() is also called by hotadd_new_pgdat() when
hot-adding memory. As a result, zone->managed_pages of the newly added
node's pgdat is set to an approximate value in the very beginning.
Even if the memory on that node has node been onlined,
/sys/device/system/node/nodeXXX/meminfo has wrong value:
hot-add node2 (memory not onlined)
cat /sys/device/system/node/node2/meminfo
Node 2 MemTotal: 33554432 kB
Node 2 MemFree: 0 kB
Node 2 MemUsed: 33554432 kB
Node 2 Active: 0 kB
This patch fixes this problem by reset node managed pages to 0 after
hot-adding a new node.
1. Move reset_managed_pages_done from reset_node_managed_pages() to
reset_all_zones_managed_pages()
2. Make reset_node_managed_pages() non-static
3. Call reset_node_managed_pages() in hotadd_new_pgdat() after pgdat
is initialized
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: <stable@vger.kernel.org> [3.16+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/bootmem.h | 1 +
mm/bootmem.c | 9 +++++----
mm/memory_hotplug.c | 9 +++++++++
mm/nobootmem.c | 8 +++++---
4 files changed, 20 insertions(+), 7 deletions(-)
diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
index 4e2bd4c95b66..0995c2de8162 100644
--- a/include/linux/bootmem.h
+++ b/include/linux/bootmem.h
@@ -46,6 +46,7 @@ extern unsigned long init_bootmem_node(pg_data_t *pgdat,
extern unsigned long init_bootmem(unsigned long addr, unsigned long memend);
extern unsigned long free_all_bootmem(void);
+extern void reset_node_managed_pages(pg_data_t *pgdat);
extern void reset_all_zones_managed_pages(void);
extern void free_bootmem_node(pg_data_t *pgdat,
diff --git a/mm/bootmem.c b/mm/bootmem.c
index 8a000cebb0d7..477be696511d 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -243,13 +243,10 @@ static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
static int reset_managed_pages_done __initdata;
-static inline void __init reset_node_managed_pages(pg_data_t *pgdat)
+void reset_node_managed_pages(pg_data_t *pgdat)
{
struct zone *z;
- if (reset_managed_pages_done)
- return;
-
for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
z->managed_pages = 0;
}
@@ -258,8 +255,12 @@ void __init reset_all_zones_managed_pages(void)
{
struct pglist_data *pgdat;
+ if (reset_managed_pages_done)
+ return;
+
for_each_online_pgdat(pgdat)
reset_node_managed_pages(pgdat);
+
reset_managed_pages_done = 1;
}
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 252e1dbbed86..c5f7fe199a60 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -31,6 +31,7 @@
#include <linux/stop_machine.h>
#include <linux/hugetlb.h>
#include <linux/memblock.h>
+#include <linux/bootmem.h>
#include <asm/tlbflush.h>
@@ -1096,6 +1097,14 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
build_all_zonelists(pgdat, NULL);
mutex_unlock(&zonelists_mutex);
+ /*
+ * zone->managed_pages is set to an approximate value in
+ * free_area_init_core(), which will cause
+ * /sys/device/system/node/nodeX/meminfo has wrong data.
+ * So reset it to 0 before any memory is onlined.
+ */
+ reset_node_managed_pages(pgdat);
+
return pgdat;
}
diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index 7c7ab32ee503..90b50468333e 100644
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -145,12 +145,10 @@ static unsigned long __init free_low_memory_core_early(void)
static int reset_managed_pages_done __initdata;
-static inline void __init reset_node_managed_pages(pg_data_t *pgdat)
+void reset_node_managed_pages(pg_data_t *pgdat)
{
struct zone *z;
- if (reset_managed_pages_done)
- return;
for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
z->managed_pages = 0;
}
@@ -159,8 +157,12 @@ void __init reset_all_zones_managed_pages(void)
{
struct pglist_data *pgdat;
+ if (reset_managed_pages_done)
+ return;
+
for_each_online_pgdat(pgdat)
reset_node_managed_pages(pgdat);
+
reset_managed_pages_done = 1;
}
From 0bd854200873894a76f32603ff2c4c988ad6b5b5 Mon Sep 17 00:00:00 2001
From: Tang Chen <tangchen@cn.fujitsu.com>
Date: Thu, 13 Nov 2014 15:19:41 -0800
Subject: [PATCH 13/15] mem-hotplug: reset node present pages when hot-adding a
new pgdat
When memory is hot-added, all the memory is in offline state. So clear
all zones' present_pages because they will be updated in online_pages()
and offline_pages(). Otherwise, /proc/zoneinfo will corrupt:
When the memory of node2 is offline:
# cat /proc/zoneinfo
......
Node 2, zone Movable
......
spanned 8388608
present 8388608
managed 0
When we online memory on node2:
# cat /proc/zoneinfo
......
Node 2, zone Movable
......
spanned 8388608
present 16777216
managed 8388608
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: <stable@vger.kernel.org> [3.16+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/memory_hotplug.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index c5f7fe199a60..1bf4807cb21e 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1067,6 +1067,16 @@ out:
}
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
+static void reset_node_present_pages(pg_data_t *pgdat)
+{
+ struct zone *z;
+
+ for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
+ z->present_pages = 0;
+
+ pgdat->node_present_pages = 0;
+}
+
/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
{
@@ -1105,6 +1115,13 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
*/
reset_node_managed_pages(pgdat);
+ /*
+ * When memory is hot-added, all the memory is in offline state. So
+ * clear all zones' present_pages because they will be updated in
+ * online_pages() and offline_pages().
+ */
+ reset_node_present_pages(pgdat);
+
return pgdat;
}
From bc53a3f46de8f3b2e28d46106216f3a759be8705 Mon Sep 17 00:00:00 2001
From: Xie XiuQi <xiexiuqi@huawei.com>
Date: Thu, 13 Nov 2014 15:19:44 -0800
Subject: [PATCH 14/15] kernel/panic.c: update comments for print_tainted
Commit 69361eef9056 ("panic: add TAINT_SOFTLOCKUP") added the 'L' flag,
but failed to update the comments for print_tainted(). So, update the
comments.
Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
kernel/panic.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/panic.c b/kernel/panic.c
index d09dc5c32c67..cf80672b7924 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -244,6 +244,7 @@ static const struct tnt tnts[] = {
* 'I' - Working around severe firmware bug.
* 'O' - Out-of-tree module has been loaded.
* 'E' - Unsigned module has been loaded.
+ * 'L' - A soft lockup has previously occurred.
*
* The string is overwritten by the next call to print_tainted().
*/
From 8fe671fc0b9f5a0d013153a9ddbd979d6eff0547 Mon Sep 17 00:00:00 2001
From: Daniel Baluta <daniel.baluta@intel.com>
Date: Thu, 13 Nov 2014 15:19:47 -0800
Subject: [PATCH 15/15] MAINTAINERS: add IIO include files
Files under include/linux/iio were not reported as part of the IIO
subsystem.
Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Reported-by: Cristina Ciocan <cristina.ciocan@intel.com>
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
MAINTAINERS | 1 +
1 file changed, 1 insertion(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index ea4d0058fd1b..60b1163dba28 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4716,6 +4716,7 @@ L: linux-iio@vger.kernel.org
S: Maintained
F: drivers/iio/
F: drivers/staging/iio/
+F: include/linux/iio/
IKANOS/ADI EAGLE ADSL USB DRIVER
M: Matthieu Castet <castet.matthieu@free.fr>