14 Nov, 2014
11 commits
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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 0When we online memory on node2:
# cat /proc/zoneinfo
......
Node 2, zone Movable
......
spanned 8388608
present 16777216
managed 8388608Signed-off-by: Tang Chen
Reviewed-by: Yasuaki Ishimatsu
Cc: [3.16+]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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 kBThis 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 initializedSigned-off-by: Tang Chen
Signed-off-by: Yasuaki Ishimatsu
Cc: [3.16+]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: Vlastimil Babka
Cc: Gioh Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Reported-by: P. Christeas
Tested-by: P. Christeas
Link: http://marc.info/?l=linux-mm&m=141508604232522&w=2
Reported-by: Norbert Preining
Tested-by: Norbert Preining
Link: https://lkml.org/lkml/2014/11/4/904
Reported-by: Pavel Machek
Link: https://lkml.org/lkml/2014/11/7/164
Cc: Joonsoo Kim
Cc: David Rientjes
Cc: Mel Gorman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Cc: Laurent Pinchart
Cc: Peter Hurley
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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=0x0000000balloc_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
Reported-by: Markos Chandras
Tested-by: Markos Chandras
Acked-by: Christoph Lameter
Cc: Pekka Enberg
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: Vlastimil Babka
Cc: "Kirill A. Shutemov"
Cc: Mel Gorman
Cc: Johannes Weiner
Cc: Minchan Kim
Cc: Yasuaki Ishimatsu
Cc: Zhang Yanfei
Cc: Tang Chen
Cc: Naoya Horiguchi
Cc: Bartlomiej Zolnierkiewicz
Cc: Wen Congyang
Cc: Marek Szyprowski
Cc: Michal Nazarewicz
Cc: Laura Abbott
Cc: Heesub Shin
Cc: "Aneesh Kumar K.V"
Cc: Ritesh Harjani
Cc: Gioh Kim
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: Vlastimil Babka
Cc: "Kirill A. Shutemov"
Cc: Mel Gorman
Cc: Johannes Weiner
Cc: Minchan Kim
Cc: Yasuaki Ishimatsu
Cc: Zhang Yanfei
Cc: Tang Chen
Cc: Naoya Horiguchi
Cc: Bartlomiej Zolnierkiewicz
Cc: Wen Congyang
Cc: Marek Szyprowski
Cc: Michal Nazarewicz
Cc: Laura Abbott
Cc: Heesub Shin
Cc: "Aneesh Kumar K.V"
Cc: Ritesh Harjani
Cc: Gioh Kim
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: Minchan Kim
Acked-by: Michal Nazarewicz
Acked-by: Vlastimil Babka
Cc: "Kirill A. Shutemov"
Cc: Mel Gorman
Cc: Johannes Weiner
Cc: Yasuaki Ishimatsu
Cc: Zhang Yanfei
Cc: Tang Chen
Cc: Naoya Horiguchi
Cc: Bartlomiej Zolnierkiewicz
Cc: Wen Congyang
Cc: Marek Szyprowski
Cc: Laura Abbott
Cc: Heesub Shin
Cc: "Aneesh Kumar K.V"
Cc: Ritesh Harjani
Cc: Gioh Kim
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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 missedWith 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
migratetypeCPU1 CPU2
get migratetype => return MIGRATE_ISOLATE
call free_one_page() with MIGRATE_ISOLATEgrab the zone lock
unisolate pageblock
release the zone lockgrab the zone lock
call __free_one_page() with MIGRATE_ISOLATE
freepage go into isolate buddy list,
although pageblock is already unisolatedThis 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
Acked-by: Minchan Kim
Acked-by: Michal Nazarewicz
Acked-by: Vlastimil Babka
Cc: "Kirill A. Shutemov"
Cc: Mel Gorman
Cc: Johannes Weiner
Cc: Yasuaki Ishimatsu
Cc: Zhang Yanfei
Cc: Tang Chen
Cc: Naoya Horiguchi
Cc: Bartlomiej Zolnierkiewicz
Cc: Wen Congyang
Cc: Marek Szyprowski
Cc: Laura Abbott
Cc: Heesub Shin
Cc: "Aneesh Kumar K.V"
Cc: Ritesh Harjani
Cc: Gioh Kim
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Cc: Vlastimil Babka
Cc: Minchan Kim
Cc: Michal Nazarewicz
Cc: Naoya Horiguchi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Nov, 2014
1 commit
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Pull xfs fixes from Dave Chinner:
"This update fixes a warning in the new pagecache_isize_extended() and
updates some related comments, another fix for zero-range
misbehaviour, and an unforntuately large set of fixes for regressions
in the bulkstat code.The bulkstat fixes are large but necessary. I wouldn't normally push
such a rework for a -rcX update, but right now xfsdump can silently
create incomplete dumps on 3.17 and it's possible that even xfsrestore
won't notice that the dumps were incomplete. Hence we need to get
this update into 3.17-stable kernels ASAP.In more detail, the refactoring work I committed in 3.17 has exposed a
major hole in our QA coverage. With both xfsdump (the major user of
bulkstat) and xfsrestore silently ignoring missing files in the
dump/restore process, incomplete dumps were going unnoticed if they
were being triggered. Many of the dump/restore filesets were so small
that they didn't evenhave a chance of triggering the loop iteration
bugs we introduced in 3.17, so we didn't exercise the code
sufficiently, either.We have already taken steps to improve QA coverage in xfstests to
avoid this happening again, and I've done a lot of manual verification
of dump/restore on very large data sets (tens of millions of inodes)
of the past week to verify this patch set results in bulkstat behaving
the same way as it does on 3.16.Unfortunately, the fixes are not exactly simple - in tracking down the
problem historic API warts were discovered (e.g xfsdump has been
working around a 20 year old bug in the bulkstat API for the past 10
years) and so that complicated the process of diagnosing and fixing
the problems. i.e. we had to fix bugs in the code as well as
discover and re-introduce the userspace visible API bugs that we
unwittingly "fixed" in 3.17 that xfsdump relied on to work correctly.Summary:
- incorrect warnings about i_mutex locking in pagecache_isize_extended()
and updates comments to match expected locking
- another zero-range bug fix for stray file size updates
- a bunch of fixes for regression in the bulkstat code introduced in
3.17"* tag 'xfs-for-linus-3.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
xfs: track bulkstat progress by agino
xfs: bulkstat error handling is broken
xfs: bulkstat main loop logic is a mess
xfs: bulkstat chunk-formatter has issues
xfs: bulkstat chunk formatting cursor is broken
xfs: bulkstat btree walk doesn't terminate
mm: Fix comment before truncate_setsize()
xfs: rework zero range to prevent invalid i_size updates
mm: Remove false WARN_ON from pagecache_isize_extended()
xfs: Check error during inode btree iteration in xfs_bulkstat()
xfs: bulkstat doesn't release AGI buffer on error
07 Nov, 2014
1 commit
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XFS doesn't always hold i_mutex when calling truncate_setsize() and it
uses a different lock to serialize truncates and writes. So fix the
comment before truncate_setsize().Reported-by: Jan Beulich
Signed-off-by: Jan Kara
Signed-off-by: Dave Chinner
04 Nov, 2014
1 commit
-
Pull CMA and DMA-mapping fixes from Marek Szyprowski:
"This contains important fixes for recently introduced highmem support
for default contiguous memory region used for dma-mapping subsystem"* 'fixes-for-v3.18' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
mm, cma: make parameters order consistent in func declaration and definition
mm: cma: Use %pa to print physical addresses
mm: cma: Ensure that reservations never cross the low/high mem boundary
mm: cma: Always consider a 0 base address reservation as dynamic
mm: cma: Don't crash on allocation if CMA area can't be activated
30 Oct, 2014
11 commits
-
The WARN_ON checking whether i_mutex is held in
pagecache_isize_extended() was wrong because some filesystems (e.g.
XFS) use different locks for serialization of truncates / writes. So
just remove the check.Signed-off-by: Jan Kara
Reviewed-by: Dave Chinner
Signed-off-by: Dave Chinner -
If CONFIG_BALLOON_COMPACTION=n balloon_page_insert() does not link pages
with balloon and doesn't set PagePrivate flag, as a result
balloon_page_dequeue() cannot get any pages because it thinks that all
of them are isolated. Without balloon compaction nobody can isolate
ballooned pages. It's safe to remove this check.Fixes: d6d86c0a7f8d ("mm/balloon_compaction: redesign ballooned pages management").
Signed-off-by: Konstantin Khlebnikov
Reported-by: Matt Mullins
Cc: [3.17]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The SLUB cache merges caches with the same size and alignment and there
was long standing bug with this behavior:- create the cache named "foo"
- create the cache named "bar" (which is merged with "foo")
- delete the cache named "foo" (but it stays allocated because "bar"
uses it)
- create the cache named "foo" again - it fails because the name "foo"
is already usedThat bug was fixed in commit 694617474e33 ("slab_common: fix the check
for duplicate slab names") by not warning on duplicate cache names when
the SLUB subsystem is used.Recently, cache merging was implemented the with SLAB subsystem too, in
12220dea07f1 ("mm/slab: support slab merge")). Therefore we need stop
checking for duplicate names even for the SLAB subsystem.This patch fixes the bug by removing the check.
Signed-off-by: Mikulas Patocka
Acked-by: Christoph Lameter
Cc: Pekka Enberg
Cc: David Rientjes
Cc: Joonsoo Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
page_remove_rmap() has too many branches on PageAnon() and is hard to
follow. Move the file part into a separate function.Signed-off-by: Johannes Weiner
Reviewed-by: Michal Hocko
Cc: Vladimir Davydov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Commit 0a31bc97c80c ("mm: memcontrol: rewrite uncharge API") changed
page migration to uncharge the old page right away. The page is locked,
unmapped, truncated, and off the LRU, but it could race with writeback
ending, which then doesn't unaccount the page properly:test_clear_page_writeback() migration
wait_on_page_writeback()
TestClearPageWriteback()
mem_cgroup_migrate()
clear PCG_USED
mem_cgroup_update_page_stat()
if (PageCgroupUsed(pc))
decrease memcg pages under writebackrelease pc->mem_cgroup->move_lock
The per-page statistics interface is heavily optimized to avoid a
function call and a lookup_page_cgroup() in the file unmap fast path,
which means it doesn't verify whether a page is still charged before
clearing PageWriteback() and it has to do it in the stat update later.Rework it so that it looks up the page's memcg once at the beginning of
the transaction and then uses it throughout. The charge will be
verified before clearing PageWriteback() and migration can't uncharge
the page as long as that is still set. The RCU lock will protect the
memcg past uncharge.As far as losing the optimization goes, the following test results are
from a microbenchmark that maps, faults, and unmaps a 4GB sparse file
three times in a nested fashion, so that there are two negative passes
that don't account but still go through the new transaction overhead.
There is no actual difference:old: 33.195102545 seconds time elapsed ( +- 0.01% )
new: 33.199231369 seconds time elapsed ( +- 0.03% )The time spent in page_remove_rmap()'s callees still adds up to the
same, but the time spent in the function itself seems reduced:# Children Self Command Shared Object Symbol
old: 0.12% 0.11% filemapstress [kernel.kallsyms] [k] page_remove_rmap
new: 0.12% 0.08% filemapstress [kernel.kallsyms] [k] page_remove_rmapSigned-off-by: Johannes Weiner
Acked-by: Michal Hocko
Cc: Vladimir Davydov
Cc: [3.17.x]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
A follow-up patch would have changed the call signature. To save the
trouble, just fold it instead.Signed-off-by: Johannes Weiner
Acked-by: Michal Hocko
Cc: Vladimir Davydov
Cc: [3.17.x]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When hot adding the same memory after hot removal, the following
messages are shown:WARNING: CPU: 20 PID: 6 at mm/page_alloc.c:4968 free_area_init_node+0x3fe/0x426()
...
Call Trace:
dump_stack+0x46/0x58
warn_slowpath_common+0x81/0xa0
warn_slowpath_null+0x1a/0x20
free_area_init_node+0x3fe/0x426
hotadd_new_pgdat+0x90/0x110
add_memory+0xd4/0x200
acpi_memory_device_add+0x1aa/0x289
acpi_bus_attach+0xfd/0x204
acpi_bus_attach+0x178/0x204
acpi_bus_scan+0x6a/0x90
acpi_device_hotplug+0xe8/0x418
acpi_hotplug_work_fn+0x1f/0x2b
process_one_work+0x14e/0x3f0
worker_thread+0x11b/0x510
kthread+0xe1/0x100
ret_from_fork+0x7c/0xb0The detaled explanation is as follows:
When hot removing memory, pgdat is set to 0 in try_offline_node(). But
if the pgdat is allocated by bootmem allocator, the clearing step is
skipped.And when hot adding the same memory, the uninitialized pgdat is reused.
But free_area_init_node() checks wether pgdat is set to zero. As a
result, free_area_init_node() hits WARN_ON().This patch clears pgdat which is allocated by bootmem allocator in
try_offline_node().Signed-off-by: Yasuaki Ishimatsu
Cc: Zhang Zhen
Cc: Wang Nan
Cc: Tang Chen
Reviewed-by: Toshi Kani
Cc: Dave Hansen
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If an anonymous mapping is not allowed to fault thp memory and then
madvise(MADV_HUGEPAGE) is used after fault, khugepaged will never
collapse this memory into thp memory.This occurs because the madvise(2) handler for thp, hugepage_madvise(),
clears VM_NOHUGEPAGE on the stack and it isn't stored in vma->vm_flags
until the final action of madvise_behavior(). This causes the
khugepaged_enter_vma_merge() to be a no-op in hugepage_madvise() when
the vma had previously had VM_NOHUGEPAGE set.Fix this by passing the correct vma flags to the khugepaged mm slot
handler. There's no chance khugepaged can run on this vma until after
madvise_behavior() returns since we hold mm->mmap_sem.It would be possible to clear VM_NOHUGEPAGE directly from vma->vm_flags
in hugepage_advise(), but I didn't want to introduce special case
behavior into madvise_behavior(). I think it's best to just let it
always set vma->vm_flags itself.Signed-off-by: David Rientjes
Reported-by: Suleiman Souhlal
Cc: "Kirill A. Shutemov"
Cc: Andrea Arcangeli
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Compound page should be freed by put_page() or free_pages() with correct
order. Not doing so will cause tail pages leaked.The compound order can be obtained by compound_order() or use
HPAGE_PMD_ORDER in our case. Some people would argue the latter is
faster but I prefer the former which is more general.This bug was observed not just on our servers (the worst case we saw is
11G leaked on a 48G machine) but also on our workstations running Ubuntu
based distro.$ cat /proc/vmstat | grep thp_zero_page_alloc
thp_zero_page_alloc 55
thp_zero_page_alloc_failed 0This means there is (thp_zero_page_alloc - 1) * (2M - 4K) memory leaked.
Fixes: 97ae17497e99 ("thp: implement refcounting for huge zero page")
Signed-off-by: Yu Zhao
Acked-by: Kirill A. Shutemov
Cc: Andrea Arcangeli
Cc: Mel Gorman
Cc: David Rientjes
Cc: Bob Liu
Cc: [3.8+]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Commit edc2ca612496 ("mm, compaction: move pageblock checks up from
isolate_migratepages_range()") commonizes isolate_migratepages variants
and make them use isolate_migratepages_block().isolate_migratepages_block() could stop the execution when enough pages
are isolated, but, there is no code in isolate_migratepages_range() to
handle this case. In the result, even if isolate_migratepages_block()
returns prematurely without checking all pages in the range,isolate_migratepages_block() is called repeately on the following
pageblock and some pages in the previous range are skipped to check.
Then, CMA is failed frequently due to this fact.To fix this problem, this patch let isolate_migratepages_range() know
the situation that enough pages are isolated and stop the isolation in
that case.Note that isolate_migratepages() has no such problem, because, it always
stops the isolation after just one call of isolate_migratepages_block().Signed-off-by: Joonsoo Kim
Acked-by: Vlastimil Babka
Cc: David Rientjes
Cc: Minchan Kim
Cc: Michal Nazarewicz
Cc: Naoya Horiguchi
Cc: Christoph Lameter
Cc: Rik van Riel
Cc: Mel Gorman
Cc: Zhang Yanfei
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Commit ff7ee93f4715 ("cgroup/kmemleak: Annotate alloc_page() for cgroup
allocations") introduces kmemleak_alloc() for alloc_page_cgroup(), but
corresponding kmemleak_free() is missing, which makes kmemleak be
wrongly disabled after memory offlining. Log is pasted at the end of
this commit message.This patch add kmemleak_free() into free_page_cgroup(). During page
offlining, this patch removes corresponding entries in kmemleak rbtree.
After that, the freed memory can be allocated again by other subsystems
without killing kmemleak.bash # for x in 1 2 3 4; do echo offline > /sys/devices/system/memory/memory$x/state ; sleep 1; done ; dmesg | grep leak
Offlined Pages 32768
kmemleak: Cannot insert 0xffff880016969000 into the object search tree (overlaps existing)
CPU: 0 PID: 412 Comm: sleep Not tainted 3.17.0-rc5+ #86
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Call Trace:
dump_stack+0x46/0x58
create_object+0x266/0x2c0
kmemleak_alloc+0x26/0x50
kmem_cache_alloc+0xd3/0x160
__sigqueue_alloc+0x49/0xd0
__send_signal+0xcb/0x410
send_signal+0x45/0x90
__group_send_sig_info+0x13/0x20
do_notify_parent+0x1bb/0x260
do_exit+0x767/0xa40
do_group_exit+0x44/0xa0
SyS_exit_group+0x17/0x20
system_call_fastpath+0x16/0x1bkmemleak: Kernel memory leak detector disabled
kmemleak: Object 0xffff880016900000 (size 524288):
kmemleak: comm "swapper/0", pid 0, jiffies 4294667296
kmemleak: min_count = 0
kmemleak: count = 0
kmemleak: flags = 0x1
kmemleak: checksum = 0
kmemleak: backtrace:
log_early+0x63/0x77
kmemleak_alloc+0x4b/0x50
init_section_page_cgroup+0x7f/0xf5
page_cgroup_init+0xc5/0xd0
start_kernel+0x333/0x408
x86_64_start_reservations+0x2a/0x2c
x86_64_start_kernel+0xf5/0xfcFixes: ff7ee93f4715 (cgroup/kmemleak: Annotate alloc_page() for cgroup allocations)
Signed-off-by: Wang Nan
Acked-by: Johannes Weiner
Acked-by: Michal Hocko
Cc: Steven Rostedt
Cc: [3.2+]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Oct, 2014
1 commit
-
When unmapping a range of pages in zap_pte_range, the page being
unmapped is added to an mmu_gather_batch structure for asynchronous
freeing. If we run out of space in the batch structure before the range
has been completely unmapped, then we break out of the loop, force a
TLB flush and free the pages that we have batched so far. If there are
further pages to unmap, then we resume the loop where we left off.Unfortunately, we forget to update addr when we break out of the loop,
which causes us to truncate the range being invalidated as the end
address is exclusive. When we re-enter the loop at the same address, the
page has already been freed and the pte_present test will fail, meaning
that we do not reconsider the address for invalidation.This patch fixes the problem by incrementing addr by the PAGE_SIZE
before breaking out of the loop on batch failure.Signed-off-by: Will Deacon
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds
27 Oct, 2014
5 commits
-
Casting physical addresses to unsigned long and using %lu truncates the
values on systems where physical addresses are larger than 32 bits. Use
%pa and get rid of the cast instead.Signed-off-by: Laurent Pinchart
Acked-by: Michal Nazarewicz
Acked-by: Geert Uytterhoeven
Signed-off-by: Marek Szyprowski -
Commit 95b0e655f914 ("ARM: mm: don't limit default CMA region only to
low memory") extended CMA memory reservation to allow usage of high
memory. It relied on commit f7426b983a6a ("mm: cma: adjust address limit
to avoid hitting low/high memory boundary") to ensure that the reserved
block never crossed the low/high memory boundary. While the
implementation correctly lowered the limit, it failed to consider the
case where the base..limit range crossed the low/high memory boundary
with enough space on each side to reserve the requested size on either
low or high memory.Rework the base and limit adjustment to fix the problem. The function
now starts by rejecting the reservation altogether for fixed
reservations that cross the boundary, tries to reserve from high memory
first and then falls back to low memory.Signed-off-by: Laurent Pinchart
Signed-off-by: Marek Szyprowski -
The fixed parameter to cma_declare_contiguous() tells the function
whether the given base address must be honoured or should be considered
as a hint only. The API considers a zero base address as meaning any
base address, which must never be considered as a fixed value.Part of the implementation correctly checks both fixed and base != 0,
but two locations check the fixed value only. Set fixed to false when
base is 0 to fix that and simplify the code.Signed-off-by: Laurent Pinchart
Acked-by: Michal Nazarewicz
Signed-off-by: Marek Szyprowski -
If activation of the CMA area fails its mutex won't be initialized,
leading to an oops at allocation time when trying to lock the mutex. Fix
this by setting the cma area count field to 0 when activation fails,
leading to allocation returning NULL immediately.Cc: # v3.17
Signed-off-by: Laurent Pinchart
Acked-by: Michal Nazarewicz
Signed-off-by: Marek Szyprowski -
Pull vfs updates from Al Viro:
"overlayfs merge + leak fix for d_splice_alias() failure exits"* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
overlayfs: embed middle into overlay_readdir_data
overlayfs: embed root into overlay_readdir_data
overlayfs: make ovl_cache_entry->name an array instead of pointer
overlayfs: don't hold ->i_mutex over opening the real directory
fix inode leaks on d_splice_alias() failure exits
fs: limit filesystem stacking depth
overlay: overlay filesystem documentation
overlayfs: implement show_options
overlayfs: add statfs support
overlay filesystem
shmem: support RENAME_WHITEOUT
ext4: support RENAME_WHITEOUT
vfs: add RENAME_WHITEOUT
vfs: add whiteout support
vfs: export check_sticky()
vfs: introduce clone_private_mount()
vfs: export __inode_permission() to modules
vfs: export do_splice_direct() to modules
vfs: add i_op->dentry_open()
25 Oct, 2014
1 commit
-
Pull ACPI and power management updates from Rafael Wysocki:
"This is material that didn't make it to my 3.18-rc1 pull request for
various reasons, mostly related to timing and travel (LinuxCon EU /
LPC) plus a couple of fixes for recent bugs.The only really new thing here is the PM QoS class for memory
bandwidth, but it is simple enough and users of it will be added in
the next cycle. One major change in behavior is that platform devices
enumerated by ACPI will use 32-bit DMA mask by default. Also included
is an ACPICA update to a new upstream release, but that's mostly
cleanups, changes in tools and similar. The rest is fixes and
cleanups mostly.Specifics:
- Fix for a recent PCI power management change that overlooked the
fact that some IRQ chips might not be able to configure PCIe PME
for system wakeup from Lucas Stach.- Fix for a bug introduced in 3.17 where acpi_device_wakeup() is
called with a wrong ordering of arguments from Zhang Rui.- A bunch of intel_pstate driver fixes (all -stable candidates) from
Dirk Brandewie, Gabriele Mazzotta and Pali Rohár.- Fixes for a rather long-standing problem with the OOM killer and
the freezer that frozen processes killed by the OOM do not actually
release any memory until they are thawed, so OOM-killing them is
rather pointless, with a couple of cleanups on top (Michal Hocko,
Cong Wang, Rafael J Wysocki).- ACPICA update to upstream release 20140926, inlcuding mostly
cleanups reducing differences between the upstream ACPICA and the
kernel code, tools changes (acpidump, acpiexec) and support for the
_DDN object (Bob Moore, Lv Zheng).- New PM QoS class for memory bandwidth from Tomeu Vizoso.
- Default 32-bit DMA mask for platform devices enumerated by ACPI
(this change is mostly needed for some drivers development in
progress targeted at 3.19) from Heikki Krogerus.- ACPI EC driver cleanups, mostly related to debugging, from Lv
Zheng.- cpufreq-dt driver updates from Thomas Petazzoni.
- powernv cpuidle driver update from Preeti U Murthy"
* tag 'pm+acpi-3.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (34 commits)
intel_pstate: Correct BYT VID values.
intel_pstate: Fix BYT frequency reporting
intel_pstate: Don't lose sysfs settings during cpu offline
cpufreq: intel_pstate: Reflect current no_turbo state correctly
cpufreq: expose scaling_cur_freq sysfs file for set_policy() drivers
cpufreq: intel_pstate: Fix setting max_perf_pct in performance policy
PCI / PM: handle failure to enable wakeup on PCIe PME
ACPI: invoke acpi_device_wakeup() with correct parameters
PM / freezer: Clean up code after recent fixes
PM: convert do_each_thread to for_each_process_thread
OOM, PM: OOM killed task shouldn't escape PM suspend
freezer: remove obsolete comments in __thaw_task()
freezer: Do not freeze tasks killed by OOM killer
ACPI / platform: provide default DMA mask
cpuidle: powernv: Populate cpuidle state details by querying the device-tree
cpufreq: cpufreq-dt: adjust message related to regulators
cpufreq: cpufreq-dt: extend with platform_data
cpufreq: allow driver-specific data
ACPI / EC: Cleanup coding style.
ACPI / EC: Refine event/query debugging messages.
...
24 Oct, 2014
1 commit
-
Allocate a dentry, initialize it with a whiteout and hash it in the place
of the old dentry. Later the old dentry will be moved away and the
whiteout will remain.i_mutex protects agains concurrent readdir.
Signed-off-by: Miklos Szeredi
Cc: Hugh Dickins
22 Oct, 2014
1 commit
-
PM freezer relies on having all tasks frozen by the time devices are
getting frozen so that no task will touch them while they are getting
frozen. But OOM killer is allowed to kill an already frozen task in
order to handle OOM situtation. In order to protect from late wake ups
OOM killer is disabled after all tasks are frozen. This, however, still
keeps a window open when a killed task didn't manage to die by the time
freeze_processes finishes.Reduce the race window by checking all tasks after OOM killer has been
disabled. This is still not race free completely unfortunately because
oom_killer_disable cannot stop an already ongoing OOM killer so a task
might still wake up from the fridge and get killed without
freeze_processes noticing. Full synchronization of OOM and freezer is,
however, too heavy weight for this highly unlikely case.Introduce and check oom_kills counter which gets incremented early when
the allocator enters __alloc_pages_may_oom path and only check all the
tasks if the counter changes during the freezing attempt. The counter
is updated so early to reduce the race window since allocator checked
oom_killer_disabled which is set by PM-freezing code. A false positive
will push the PM-freezer into a slow path but that is not a big deal.Changes since v1
- push the re-check loop out of freeze_processes into
check_frozen_processes and invert the condition to make the code more
readable as per RafaelFixes: f660daac474c6f (oom: thaw threads if oom killed thread is frozen before deferring)
Cc: 3.2+ # 3.2+
Signed-off-by: Michal Hocko
Signed-off-by: Rafael J. Wysocki
21 Oct, 2014
1 commit
-
Pull ext4 updates from Ted Ts'o:
"A large number of cleanups and bug fixes, with some (minor) journal
optimizations"[ This got sent to me before -rc1, but was stuck in my spam folder. - Linus ]
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (67 commits)
ext4: check s_chksum_driver when looking for bg csum presence
ext4: move error report out of atomic context in ext4_init_block_bitmap()
ext4: Replace open coded mdata csum feature to helper function
ext4: delete useless comments about ext4_move_extents
ext4: fix reservation overflow in ext4_da_write_begin
ext4: add ext4_iget_normal() which is to be used for dir tree lookups
ext4: don't orphan or truncate the boot loader inode
ext4: grab missed write_count for EXT4_IOC_SWAP_BOOT
ext4: optimize block allocation on grow indepth
ext4: get rid of code duplication
ext4: fix over-defensive complaint after journal abort
ext4: fix return value of ext4_do_update_inode
ext4: fix mmap data corruption when blocksize < pagesize
vfs: fix data corruption when blocksize < pagesize for mmaped data
ext4: fold ext4_nojournal_sops into ext4_sops
ext4: support freezing ext2 (nojournal) file systems
ext4: fold ext4_sync_fs_nojournal() into ext4_sync_fs()
ext4: don't check quota format when there are no quota files
jbd2: simplify calling convention around __jbd2_journal_clean_checkpoint_list
jbd2: avoid pointless scanning of checkpoint lists
...
19 Oct, 2014
1 commit
-
Pull core block layer changes from Jens Axboe:
"This is the core block IO pull request for 3.18. Apart from the new
and improved flush machinery for blk-mq, this is all mostly bug fixes
and cleanups.- blk-mq timeout updates and fixes from Christoph.
- Removal of REQ_END, also from Christoph. We pass it through the
->queue_rq() hook for blk-mq instead, freeing up one of the request
bits. The space was overly tight on 32-bit, so Martin also killed
REQ_KERNEL since it's no longer used.- blk integrity updates and fixes from Martin and Gu Zheng.
- Update to the flush machinery for blk-mq from Ming Lei. Now we
have a per hardware context flush request, which both cleans up the
code should scale better for flush intensive workloads on blk-mq.- Improve the error printing, from Rob Elliott.
- Backing device improvements and cleanups from Tejun.
- Fixup of a misplaced rq_complete() tracepoint from Hannes.
- Make blk_get_request() return error pointers, fixing up issues
where we NULL deref when a device goes bad or missing. From Joe
Lawrence.- Prep work for drastically reducing the memory consumption of dm
devices from Junichi Nomura. This allows creating clone bio sets
without preallocating a lot of memory.- Fix a blk-mq hang on certain combinations of queue depths and
hardware queues from me.- Limit memory consumption for blk-mq devices for crash dump
scenarios and drivers that use crazy high depths (certain SCSI
shared tag setups). We now just use a single queue and limited
depth for that"* 'for-3.18/core' of git://git.kernel.dk/linux-block: (58 commits)
block: Remove REQ_KERNEL
blk-mq: allocate cpumask on the home node
bio-integrity: remove the needless fail handle of bip_slab creating
block: include func name in __get_request prints
block: make blk_update_request print prefix match ratelimited prefix
blk-merge: don't compute bi_phys_segments from bi_vcnt for cloned bio
block: fix alignment_offset math that assumes io_min is a power-of-2
blk-mq: Make bt_clear_tag() easier to read
blk-mq: fix potential hang if rolling wakeup depth is too high
block: add bioset_create_nobvec()
block: use bio_clone_fast() in blk_rq_prep_clone()
block: misplaced rq_complete tracepoint
sd: Honor block layer integrity handling flags
block: Replace strnicmp with strncasecmp
block: Add T10 Protection Information functions
block: Don't merge requests if integrity flags differ
block: Integrity checksum flag
block: Relocate bio integrity flags
block: Add a disk flag to block integrity profile
block: Add prefix to block integrity profile flags
...
14 Oct, 2014
4 commits
-
Merge second patch-bomb from Andrew Morton:
- a few hotfixes
- drivers/dma updates
- MAINTAINERS updates
- Quite a lot of lib/ updates
- checkpatch updates
- binfmt updates
- autofs4
- drivers/rtc/
- various small tweaks to less used filesystems
- ipc/ updates
- kernel/watchdog.c changes* emailed patches from Andrew Morton : (135 commits)
mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared
kernel/param: consolidate __{start,stop}___param[] in
ia64: remove duplicate declarations of __per_cpu_start[] and __per_cpu_end[]
frv: remove unused declarations of __start___ex_table and __stop___ex_table
kvm: ensure hard lockup detection is disabled by default
kernel/watchdog.c: control hard lockup detection default
staging: rtl8192u: use %*pEn to escape buffer
staging: rtl8192e: use %*pEn to escape buffer
staging: wlan-ng: use %*pEhp to print SN
lib80211: remove unused print_ssid()
wireless: hostap: proc: print properly escaped SSID
wireless: ipw2x00: print SSID via %*pE
wireless: libertas: print esaped string via %*pE
lib/vsprintf: add %*pE[achnops] format specifier
lib / string_helpers: introduce string_escape_mem()
lib / string_helpers: refactoring the test suite
lib / string_helpers: move documentation to c-file
include/linux: remove strict_strto* definitions
arch/x86/mm/numa.c: fix boot failure when all nodes are hotpluggable
fs: check bh blocknr earlier when searching lru
... -
Pull x86 mm updates from Ingo Molnar:
"This tree includes the following changes:- fix memory hotplug
- fix hibernation bootup memory layout assumptions
- fix hyperv numa guest kernel messages
- remove dead code
- update documentation"* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Update memory map description to list hypervisor-reserved area
x86/mm, hibernate: Do not assume the first e820 area to be RAM
x86/mm/numa: Drop dead code and rename setup_node_data() to setup_alloc_data()
x86/mm/hotplug: Modify PGD entry when removing memory
x86/mm/hotplug: Pass sync_global_pgds() a correct argument in remove_pagetable()
x86: Remove set_pmd_pfn -
For VMAs that don't want write notifications, PTEs created for read faults
have their write bit set. If the read fault happens after VM_SOFTDIRTY is
cleared, then the PTE's softdirty bit will remain clear after subsequent
writes.Here's a simple code snippet to demonstrate the bug:
char* m = mmap(NULL, getpagesize(), PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_SHARED, -1, 0);
system("echo 4 > /proc/$PPID/clear_refs"); /* clear VM_SOFTDIRTY */
assert(*m == '\0'); /* new PTE allows write access */
assert(!soft_dirty(x));
*m = 'x'; /* should dirty the page */
assert(soft_dirty(x)); /* fails */With this patch, write notifications are enabled when VM_SOFTDIRTY is
cleared. Furthermore, to avoid unnecessary faults, write notifications
are disabled when VM_SOFTDIRTY is set.As a side effect of enabling and disabling write notifications with
care, this patch fixes a bug in mprotect where vm_page_prot bits set by
drivers were zapped on mprotect. An analogous bug was fixed in mmap by
commit c9d0bf241451 ("mm: uncached vma support with writenotify").Signed-off-by: Peter Feiner
Reported-by: Peter Feiner
Suggested-by: Kirill A. Shutemov
Cc: Cyrill Gorcunov
Cc: Pavel Emelyanov
Cc: Jamie Liu
Cc: Hugh Dickins
Cc: Naoya Horiguchi
Cc: Bjorn Helgaas
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a function to create CMA region from previously reserved memory and
add support for handling 'shared-dma-pool' reserved-memory device tree
nodes.Based on previous code provided by Josh Cartwright
Signed-off-by: Marek Szyprowski
Cc: Arnd Bergmann
Cc: Michal Nazarewicz
Cc: Grant Likely
Cc: Laura Abbott
Cc: Josh Cartwright
Cc: Joonsoo Kim
Cc: Kyungmin Park
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
