Vladimir Davydov [Wed, 14 May 2014 00:01:49 +0000 (10:01 +1000)]
Documentation/memcg: warn about incomplete kmemcg state
Kmemcg is currently under development and lacks some important features.
In particular, it does not have support of kmem reclaim on memory pressure
inside cgroup, which practically makes it unusable in real life. Let's
warn about it in both Kconfig and Documentation to prevent complaints
arising.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Dave Hansen [Wed, 14 May 2014 00:01:49 +0000 (10:01 +1000)]
mm: debug: make bad_range() output more usable and readable
Nobody outputs memory addresses in decimal. PFNs are essentially
addresses, and they're gibberish in decimal. Output them in hex.
Also, add the nid and zone name to give a little more context to the
message.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Joonsoo Kim [Wed, 14 May 2014 00:01:49 +0000 (10:01 +1000)]
mm-compaction-cleanup-isolate_freepages-fix3
What I did here is taking end_pfn out of the loop and considering zone
boundary once. After then, we can just set previous pfn to end_pfn on
every iteration to move scanning window. With this change, we can remove
local variable, z_end_pfn.
Another things I did are removing max() operation and un-needed assignment
to isolate variable.
In addition, I change both the variable names, from pfn and end_pfn to
block_start_pfn and block_end_pfn, respectively. They represent their
meaning perfectly.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Cc: Dongjun Shin <d.j.shin@samsung.com> Cc: Sunghwan Yun <sunghwan.yun@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vlastimil Babka [Wed, 14 May 2014 00:01:48 +0000 (10:01 +1000)]
mm-compaction-cleanup-isolate_freepages-fix 2
Cleanup detection of compaction scanners crossing in isolate_freepages().
To make sure compact_finished() observes scanners crossing, we can just
set free_pfn to migrate_pfn instead of confusing max() construct.
Suggested-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dongjun Shin <d.j.shin@samsung.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Rik van Riel <riel@redhat.com> Cc: Sunghwan Yun <sunghwan.yun@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vlastimil Babka [Wed, 14 May 2014 00:01:48 +0000 (10:01 +1000)]
mm/compaction: cleanup isolate_freepages()
isolate_freepages() is currently somewhat hard to follow thanks to many
looks like it is related to the 'low_pfn' variable, but in fact it is not.
This patch renames the 'high_pfn' variable to a hopefully less confusing name,
and slightly changes its handling without a functional change. A comment made
obsolete by recent changes is also updated.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Cc: Dongjun Shin <d.j.shin@samsung.com> Cc: Sunghwan Yun <sunghwan.yun@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vlastimil Babka [Wed, 14 May 2014 00:01:47 +0000 (10:01 +1000)]
mm/page_alloc: prevent MIGRATE_RESERVE pages from being misplaced
For the MIGRATE_RESERVE pages, it is important they do not get misplaced
on free_list of other migratetype, otherwise the whole MIGRATE_RESERVE
pageblock might be changed to other migratetype in
try_to_steal_freepages().
Currently, it is however possible for this to happen when MIGRATE_RESERVE
page is allocated on pcplist through rmqueue_bulk() as a fallback for
other desired migratetype, and then later freed back through
free_pcppages_bulk() without being actually used. This happens because
free_pcppages_bulk() uses get_freepage_migratetype() to choose the
free_list, and rmqueue_bulk() calls set_freepage_migratetype() with the
*desired* migratetype and not the page's original MIGRATE_RESERVE
migratetype.
This patch fixes the problem by moving the call to
set_freepage_migratetype() from rmqueue_bulk() down to
__rmqueue_smallest() and __rmqueue_fallback() where the actual page's
migratetype (e.g. from which free_list the page is taken from) is used.
Note that this migratetype might be different from the pageblock's
migratetype due to freepage stealing decisions. This is OK, as page
stealing never uses MIGRATE_RESERVE as a fallback, and also takes care to
leave all MIGRATE_CMA pages on the correct freelist.
Therefore, as an additional benefit, the call to
get_pageblock_migratetype() from rmqueue_bulk() when CMA is enabled, can
be removed completely. This relies on the fact that MIGRATE_CMA
pageblocks are created only during system init, and the above. The
related is_migrate_isolate() check is also unnecessary, as memory
isolation has other ways to move pages between freelists, and drain pcp
lists containing pages that should be isolated. The buffered_rmqueue()
can also benefit from calling get_freepage_migratetype() instead of
get_pageblock_migratetype().
A separate patch will add VM_BUG_ON checks for the invariant that for
MIGRATE_RESERVE and MIGRATE_CMA pageblocks, freepage_migratetype must
equal to pageblock_migratetype so that these pages always go to the
correct free_list.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Yong-Taek Lee <ytk.lee@samsung.com> Reported-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Suggested-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Suggested-by: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan@kernel.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vladimir Davydov [Wed, 14 May 2014 00:01:47 +0000 (10:01 +1000)]
slab: get_online_mems for kmem_cache_{create,destroy,shrink}
When we create a sl[au]b cache, we allocate kmem_cache_node structures for
each online NUMA node. To handle nodes taken online/offline, we register
memory hotplug notifier and allocate/free kmem_cache_node corresponding to
the node that changes its state for each kmem cache.
To synchronize between the two paths we hold the slab_mutex during both
the cache creationg/destruction path and while tuning per-node parts of
kmem caches in memory hotplug handler, but that's not quite right, because
it does not guarantee that a newly created cache will have all
kmem_cache_nodes initialized in case it races with memory hotplug. For
instance, in case of slub:
CPU0 CPU1
---- ----
kmem_cache_create: online_pages:
__kmem_cache_create: slab_memory_callback:
slab_mem_going_online_callback:
lock slab_mutex
for each slab_caches list entry
allocate kmem_cache node
unlock slab_mutex
lock slab_mutex
init_kmem_cache_nodes:
for_each_node_state(node, N_NORMAL_MEMORY)
allocate kmem_cache node
add kmem_cache to slab_caches list
unlock slab_mutex
online_pages (continued):
node_states_set_node
As a result we'll get a kmem cache with not all kmem_cache_nodes
allocated.
To avoid issues like that we should hold get/put_online_mems() during the
whole kmem cache creation/destruction/shrink paths, just like we deal with
cpu hotplug. This patch does the trick.
Note, that after it's applied, there is no need in taking the slab_mutex
for kmem_cache_shrink any more, so it is removed from there.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vladimir Davydov [Wed, 14 May 2014 00:01:47 +0000 (10:01 +1000)]
mem-hotplug: implement get/put_online_mems
kmem_cache_{create,destroy,shrink} need to get a stable value of cpu/node
online mask, because they init/destroy/access per-cpu/node kmem_cache
parts, which can be allocated or destroyed on cpu/mem hotplug. To protect
against cpu hotplug, these functions use {get,put}_online_cpus. However,
they do nothing to synchronize with memory hotplug - taking the slab_mutex
does not eliminate the possibility of race as described in patch 2.
What we need there is something like get_online_cpus, but for memory. We
already have lock_memory_hotplug, which serves for the purpose, but it's a
bit of a hammer right now, because it's backed by a mutex. As a result,
it imposes some limitations to locking order, which are not desirable, and
can't be used just like get_online_cpus. That's why in patch 1 I
substitute it with get/put_online_mems, which work exactly like
get/put_online_cpus except they block not cpu, but memory hotplug.
[ v1 can be found at https://lkml.org/lkml/2014/4/6/68. I NAK'ed it by
myself, because it used an rw semaphore for get/put_online_mems, making
them dead lock prune. ]
This patch (of 2):
{un}lock_memory_hotplug, which is used to synchronize against memory
hotplug, is currently backed by a mutex, which makes it a bit of a hammer
- threads that only want to get a stable value of online nodes mask won't
be able to proceed concurrently. Also, it imposes some strong locking
ordering rules on it, which narrows down the set of its usage scenarios.
This patch introduces get/put_online_mems, which are the same as
get/put_online_cpus, but for memory hotplug, i.e. executing a code inside
a get/put_online_mems section will guarantee a stable value of online
nodes, present pages, etc.
lock_memory_hotplug()/unlock_memory_hotplug() are removed altogether.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mel Gorman [Wed, 14 May 2014 00:01:46 +0000 (10:01 +1000)]
mm: page_alloc: do not cache reclaim distances
pgdat->reclaim_nodes tracks if a remote node is allowed to be reclaimed by
zone_reclaim due to its distance. As it is expected that zone_reclaim_mode
will be rarely enabled it is unreasonable for all machines to take a penalty.
Fortunately, the zone_reclaim_mode() path is already slow and it is the path
that takes the hit.
Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mel Gorman [Wed, 14 May 2014 00:01:46 +0000 (10:01 +1000)]
mm: disable zone_reclaim_mode by default
When it was introduced, zone_reclaim_mode made sense as NUMA distances
punished and workloads were generally partitioned to fit into a NUMA node.
NUMA machines are now common but few of the workloads are NUMA-aware and
it's routine to see major performance degradation due to zone_reclaim_mode
being enabled but relatively few can identify the problem.
Those that require zone_reclaim_mode are likely to be able to detect when
it needs to be enabled and tune appropriately so lets have a sensible
default for the bulk of users.
This patch (of 2):
zone_reclaim_mode causes processes to prefer reclaiming memory from local
node instead of spilling over to other nodes. This made sense initially when
NUMA machines were almost exclusively HPC and the workload was partitioned
into nodes. The NUMA penalties were sufficiently high to justify reclaiming
the memory. On current machines and workloads it is often the case that
zone_reclaim_mode destroys performance but not all users know how to detect
this. Favour the common case and disable it by default. Users that are
sophisticated enough to know they need zone_reclaim_mode will detect it.
Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
WARNING: braces {} are not necessary for any arm of this statement
#282: FILE: mm/hugetlb.c:1650:
+ if (hstate_is_gigantic(h)) {
[...]
+ } else {
[...]
total: 0 errors, 1 warnings, 219 lines checked
./patches/hugetlb-add-support-for-gigantic-page-allocation-at-runtime.patch has style problems, please review.
If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.
Please run checkpatch prior to sending patches
Cc: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Luiz Capitulino [Wed, 14 May 2014 00:01:45 +0000 (10:01 +1000)]
hugetlb: add support for gigantic page allocation at runtime
HugeTLB is limited to allocating hugepages whose size are less than
MAX_ORDER order. This is so because HugeTLB allocates hugepages via the
buddy allocator. Gigantic pages (that is, pages whose size is greater
than MAX_ORDER order) have to be allocated at boottime.
However, boottime allocation has at least two serious problems. First, it
doesn't support NUMA and second, gigantic pages allocated at boottime
can't be freed.
This commit solves both issues by adding support for allocating gigantic
pages during runtime. It works just like regular sized hugepages, meaning
that the interface in sysfs is the same, it supports NUMA, and gigantic
pages can be freed.
For example, on x86_64 gigantic pages are 1GB big. To allocate two 1G
gigantic pages on node 1, one can do:
The one problem with gigantic page allocation at runtime is that it can't
be serviced by the buddy allocator. To overcome that problem, this commit
scans all zones from a node looking for a large enough contiguous region.
When one is found, it's allocated by using CMA, that is, we call
alloc_contig_range() to do the actual allocation. For example, on x86_64
we scan all zones looking for a 1GB contiguous region. When one is found,
it's allocated by alloc_contig_range().
One expected issue with that approach is that such gigantic contiguous
regions tend to vanish as runtime goes by. The best way to avoid this for
now is to make gigantic page allocations very early during system boot,
say from a init script. Other possible optimization include using
compaction, which is supported by CMA but is not explicitly used by this
commit.
It's also important to note the following:
1. Gigantic pages allocated at boottime by the hugepages= command-line
option can be freed at runtime just fine
2. This commit adds support for gigantic pages only to x86_64. The
reason is that I don't have access to nor experience with other archs.
The code is arch indepedent though, so it should be simple to add
support to different archs
3. I didn't add support for hugepage overcommit, that is allocating
a gigantic page on demand when
/proc/sys/vm/nr_overcommit_hugepages > 0. The reason is that I don't
think it's reasonable to do the hard and long work required for
allocating a gigantic page at fault time. But it should be simple
to add this if wanted
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Rik van Riel <riel@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Luiz Capitulino [Wed, 14 May 2014 00:01:45 +0000 (10:01 +1000)]
hugetlb: move helpers up in the file
Next commit will add new code which will want to call
for_each_node_mask_to_alloc() macro. Move it, its buddy
for_each_node_mask_to_free() and their dependencies up in the file so the
new code can use them. This is just code movement, no logic change.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Luiz Capitulino [Wed, 14 May 2014 00:01:44 +0000 (10:01 +1000)]
hugetlb: prep_compound_gigantic_page(): drop __init marker
The HugeTLB subsystem uses the buddy allocator to allocate hugepages
during runtime. This means that hugepages allocation during runtime is
limited to MAX_ORDER order. For archs supporting gigantic pages (that is,
page sizes greater than MAX_ORDER), this in turn means that those pages
can't be allocated at runtime.
HugeTLB supports gigantic page allocation during boottime, via the boot
allocator. To this end the kernel provides the command-line options
hugepagesz= and hugepages=, which can be used to instruct the kernel to
allocate N gigantic pages during boot.
For example, x86_64 supports 2M and 1G hugepages, but only 2M hugepages
can be allocated and freed at runtime. If one wants to allocate 1G
gigantic pages, this has to be done at boot via the hugepagesz= and
hugepages= command-line options.
Now, gigantic page allocation at boottime has two serious problems:
1. Boottime allocation is not NUMA aware. On a NUMA machine the kernel
evenly distributes boottime allocated hugepages among nodes.
For example, suppose you have a four-node NUMA machine and want
to allocate four 1G gigantic pages at boottime. The kernel will
allocate one gigantic page per node.
On the other hand, we do have users who want to be able to specify
which NUMA node gigantic pages should allocated from. So that they
can place virtual machines on a specific NUMA node.
2. Gigantic pages allocated at boottime can't be freed
At this point it's important to observe that regular hugepages allocated
at runtime don't have those problems. This is so because HugeTLB
interface for runtime allocation in sysfs supports NUMA and runtime
allocated pages can be freed just fine via the buddy allocator.
This series adds support for allocating gigantic pages at runtime. It
does so by allocating gigantic pages via CMA instead of the buddy
allocator. Releasing gigantic pages is also supported via CMA. As this
series builds on top of the existing HugeTLB interface, it makes gigantic
page allocation and releasing just like regular sized hugepages. This
also means that NUMA support just works.
For example, to allocate two 1G gigantic pages on node 1, one can do:
Vladimir Davydov [Wed, 14 May 2014 00:01:44 +0000 (10:01 +1000)]
slab: document kmalloc_order
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Li Zhong [Wed, 14 May 2014 00:01:43 +0000 (10:01 +1000)]
memory-hotplug: update documentation to hide information about SECTIONS and remove end_phys_index
Seems we all agree that information about SECTION, e.g. section size,
sections per memory block should be kept as kernel internals, and not
exposed to userspace.
This patch updates Documentation/memory-hotplug.txt to refer to memory
blocks instead of memory sections where appropriate and added a paragraph
to explain that memory blocks are made of memory sections. The
documentation update is mostly provided by Nathan.
Also, as end_phys_index in code is actually not the end section id, but
the end memory block id, which should always be the same as phys_index.
So it is removed here.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Dave Hansen [Wed, 14 May 2014 00:01:43 +0000 (10:01 +1000)]
mm: pass VM_BUG_ON() reason to dump_page()
I recently added a patch to let folks pass a "reason" string dump_page()
which gets dumped out along with the page's data. This essentially saves
the bug-reader a trip in to the source to figure out why we BUG_ON()'d.
The new VM_BUG_ON_PAGE() passes in NULL for "reason". It seems like we
might as well pass the BUG_ON() condition if we have it. This will bloat
kernels a bit with ~160 new strings, but this is all under a debugging
option anyway.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Johannes Weiner [Wed, 14 May 2014 00:01:43 +0000 (10:01 +1000)]
mm: memcontrol: remove hierarchy restrictions for swappiness and oom_control
Per-memcg swappiness and oom killing can currently not be tweaked on a
memcg that is part of a hierarchy, but not the root of that hierarchy.
Users have complained that they can't configure this when they turned on
hierarchy mode. In fact, with hierarchy mode becoming the default, this
restriction disables the tunables entirely.
But there is no good reason for this restriction. The settings for
swappiness and OOM killing are taken from whatever memcg whose limit
triggered reclaim and OOM invocation, regardless of its position in the
hierarchy tree.
Allow setting swappiness on any group. The knob on the root memcg already
reads the global VM swappiness, make it writable as well.
Allow disabling the OOM killer on any non-root memcg.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
printk is meant to be used with an associated log level. There are some
instances of printk scattered around the mm code where the log level is
missing. Add a log level and adhere to suggestions by
scripts/checkpatch.pl by moving to the pr_* macros.
Also add the typical pr_fmt definition so that print statements can be
easily traced back to the modules where they occur, correlated one with
another, etc. This will require the removal of some (now redundant)
prefixes on a few print statements.
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
thp: consolidate assert checks in __split_huge_page()
It doesn't make sense to have two assert checks for each invariant: one
for printing and one for BUG().
Let's trigger BUG() if we print error message.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Akinobu Mita [Wed, 14 May 2014 00:01:41 +0000 (10:01 +1000)]
arch/x86/kernel/pci-dma.c: fix dma_generic_alloc_coherent() when CONFIG_DMA_CMA is enabled
dma_generic_alloc_coherent() firstly attempts to allocate by
dma_alloc_from_contiguous() if CONFIG_DMA_CMA is enabled. But the memory
region allocated by it may not fit within the device's DMA mask. This
change makes it fall back to usual alloc_pages_node() allocation for such
cases.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Don Dutile <ddutile@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Akinobu Mita [Wed, 14 May 2014 00:01:41 +0000 (10:01 +1000)]
cma: add placement specifier for "cma=" kernel parameter
Currently, "cma=" kernel parameter is used to specify the size of CMA, but
we can't specify where it is located. We want to locate CMA below 4GB for
devices only supporting 32-bit addressing on 64-bit systems without iommu.
This enables to specify the placement of CMA by extending "cma=" kernel
parameter.
Examples:
1. locate 64MB CMA below 4GB by "cma=64M@0-4G"
2. locate 64MB CMA exact at 512MB by "cma=64M@512M"
Note that the DMA contiguous memory allocator on x86 assumes that
page_address() works for the pages to allocate. So this change requires
to limit end address of contiguous memory area upto max_pfn_mapped to
prevent from locating it on highmem area by the argument of
dma_contiguous_reserve().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Don Dutile <ddutile@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Akinobu Mita [Wed, 14 May 2014 00:01:40 +0000 (10:01 +1000)]
memblock: introduce memblock_alloc_range()
This introduces memblock_alloc_range() which allocates memblock from the
specified range of physical address. I would like to use this function to
specify the location of CMA.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Don Dutile <ddutile@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Akinobu Mita [Wed, 14 May 2014 00:01:40 +0000 (10:01 +1000)]
intel-iommu: add missing include of dma-contiguous.h
This patch fixes build error on ia64, that is introduced by the patch
intel-iommu-integrate-dma-cma.patch in -mm tree, and this change should
be folded into it.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Akinobu Mita [Wed, 14 May 2014 00:01:40 +0000 (10:01 +1000)]
intel-iommu: integrate DMA CMA
This adds support for the DMA Contiguous Memory Allocator for intel-iommu.
This change enables dma_alloc_coherent() to allocate big contiguous
memory.
It is achieved in the same way as nommu_dma_ops currently does, i.e.
trying to allocate memory by dma_alloc_from_contiguous() and alloc_pages()
is used as a fallback.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Don Dutile <ddutile@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Akinobu Mita [Wed, 14 May 2014 00:01:40 +0000 (10:01 +1000)]
x86: enable DMA CMA with swiotlb
The DMA Contiguous Memory Allocator support on x86 is disabled when
swiotlb config option is enabled. So DMA CMA is always disabled on x86_64
because swiotlb is always enabled. This attempts to support for DMA CMA
with enabling swiotlb config option.
The contiguous memory allocator on x86 is integrated in the function
dma_generic_alloc_coherent() which is .alloc callback in nommu_dma_ops for
dma_alloc_coherent().
x86_swiotlb_alloc_coherent() which is .alloc callback in swiotlb_dma_ops
tries to allocate with dma_generic_alloc_coherent() firstly and then
swiotlb_alloc_coherent() is called as a fallback.
The main part of supporting DMA CMA with swiotlb is that changing
x86_swiotlb_free_coherent() which is .free callback in swiotlb_dma_ops for
dma_free_coherent() so that it can distinguish memory allocated by
dma_generic_alloc_coherent() from one allocated by
swiotlb_alloc_coherent() and release it with dma_generic_free_coherent()
which can handle contiguous memory. This change requires making
is_swiotlb_buffer() global function.
This also needs to change .free callback in the dma_map_ops for amd_gart
and sta2x11, because these dma_ops are also using
dma_generic_alloc_coherent().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Don Dutile <ddutile@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Akinobu Mita [Wed, 14 May 2014 00:01:39 +0000 (10:01 +1000)]
arch/x86/kernel/pci-dma.c: avoid duplicated memset in dma_generic_alloc_coherent()
Fix a duplicated memset that was introduced by the patch
x86-make-dma_alloc_coherent-return-zeroed-memory-if-cma-is-enabled.patch
in -mm tree, and this change should be folded into it.
If dma_generic_alloc_coherent() is called with __GFP_ZERO, it does a
duplicated memset to the memory area allocated by alloc_pages_node() with
__GFP_ZERO. This change fixes that inefficiency by clearing __GFP_ZERO
bit in gfp flages before calling alloc_pages_node(). Note that
dma_generic_alloc_coherent() always returns zeroed memory.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Don Dutile <ddutile@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Akinobu Mita [Wed, 14 May 2014 00:01:39 +0000 (10:01 +1000)]
x86: make dma_alloc_coherent() return zeroed memory if CMA is enabled
This patchset enhances the DMA Contiguous Memory Allocator on x86.
Currently the DMA CMA is only supported with pci-nommu dma_map_ops and
furthermore it can't be enabled on x86_64. But I would like to allocate
big contiguous memory with dma_alloc_coherent() and tell it to the device
that requires it, regardless of which dma mapping implementation is
actually used in the system.
So this makes it work with swiotlb and intel-iommu dma_map_ops, too. And
this also extends "cma=" kernel parameter to specify placement constraint
by the physical address range of memory allocations. For example, CMA
allocates memory below 4GB by "cma=64M@0-4G", it is required for the
devices only supporting 32-bit addressing on 64-bit systems without iommu.
This patch (of 5):
Calling dma_alloc_coherent() with __GFP_ZERO must return zeroed memory.
But when the contiguous memory allocator (CMA) is enabled on x86 and the
memory region is allocated by dma_alloc_from_contiguous(), it doesn't
return zeroed memory. Because dma_generic_alloc_coherent() forgot to fill
the memory region with zero if it was allocated by
dma_alloc_from_contiguous()
Most implementations of dma_alloc_coherent() return zeroed memory
regardless of whether __GFP_ZERO is specified. So this fixes it by
unconditionally zeroing the allocated memory region.
Alternatively, we could fix dma_alloc_from_contiguous() to return zeroed
out memory and remove memset() from all caller of it. But we can't simply
remove the memset on arm because __dma_clear_buffer() is used there for
ensuring cache flushing and it is used in many places. Of course we can
do redundant memset in dma_alloc_from_contiguous(), but I think this patch
is less impact for fixing this problem.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Don Dutile <ddutile@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
For single threaded workloads, we can avoid flushing and iterating through
the entire list of tasks, making the whole function a lot faster,
requiring only a single atomic read for the mm_users.
Suleiman Souhlal [Wed, 14 May 2014 00:01:38 +0000 (10:01 +1000)]
mm: only force scan in reclaim when none of the LRUs are big enough.
Prior to this change, we would decide whether to force scan a LRU during
reclaim if that LRU itself was too small for the current priority.
However, this can lead to the file LRU getting force scanned even if there
are a lot of anonymous pages we can reclaim, leading to hot file pages
getting needlessly reclaimed.
To address this, we instead only force scan when none of the reclaimable
LRUs are big enough.
Gives huge improvements with zswap. For example, when doing -j20 kernel
build in a 500MB container with zswap enabled, runtime (in seconds) is
greatly reduced:
x without this change
+ with this change
N Min Max Median Avg Stddev
x 5 700.997 790.076 763.928 754.05 39.59493
+ 5 141.634 197.899 155.706 161.9 21.270224
Difference at 95.0% confidence
-592.15 +/- 46.3521
-78.5293% +/- 6.14709%
(Student's t, pooled s = 31.7819)
Should also give some improvements in regular (non-zswap) swap cases.
Yes, hughd found significant speedup using regular swap, with several
memcgs under pressure; and it should also be effective in the non-memcg
case, whenever one or another zone LRU is forced too small.
Signed-off-by: Suleiman Souhlal <suleiman@google.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Rafael Aquini <aquini@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Bob Liu <bob.liu@oracle.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Luigi Semenzato <semenzato@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Roman Pen [Wed, 14 May 2014 00:01:38 +0000 (10:01 +1000)]
fs/mpage.c: forgotten WRITE_SYNC in case of data integrity write
In case of wbc->sync_mode == WB_SYNC_ALL we need to do data integrity
write, thus mark request as WRITE_SYNC.
akpm: afaict this change will cause the data integrity write bios to be
placed onto the second queue in cfq_io_cq.cfqq[], which presumably results
in special treatment. The documentation for REQ_SYNC is horrid.
Signed-off-by: Roman Pen <r.peniaev@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cyrill Gorcunov [Wed, 14 May 2014 00:01:37 +0000 (10:01 +1000)]
mm: softdirty: clear VM_SOFTDIRTY flag inside clear_refs_write() instead of clear_soft_dirty()
clear_refs_write() is called earlier than clear_soft_dirty() and it is
more natural to clear VM_SOFTDIRTY (which belongs to VMA entry but not
PTEs) that early instead of clearing it a way deeper inside call chain.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cyrill Gorcunov [Wed, 14 May 2014 00:01:37 +0000 (10:01 +1000)]
mm: softdirty: don't forget to save file map softdiry bit on unmap
pte_file_mksoft_dirty operates with argument passed by a value and returns
modified result thus we need to assign @ptfile here, otherwise itis a no-op
which may lead to loss of the softdirty bit.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cyrill Gorcunov [Wed, 14 May 2014 00:01:37 +0000 (10:01 +1000)]
mm: softdirty: make freshly remapped file pages being softdirty unconditionally
Hugh reported:
| I noticed your soft_dirty work in install_file_pte(): which looked
| good at first, until I realized that it's propagating the soft_dirty
| of a pte it's about to zap completely, to the unrelated entry it's
| about to insert in its place. Which seems very odd to me.
Indeed this code ends up being nop in result -- pte_file_mksoft_dirty()
operates with pte_t argument and returns new pte_t which were never used
after. After looking more I think what we need is to soft-dirtify all
newely remapped file pages because it should look like a new mapping for
memory tracker.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Reported-by: Hugh Dickins <hughd@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Naoya Horiguchi [Wed, 14 May 2014 00:01:36 +0000 (10:01 +1000)]
mm: add !pte_present() check on existing hugetlb_entry callbacks
Page table walker doesn't check non-present hugetlb entry in common path,
so hugetlb_entry() callbacks must check it. The reason for this behavior
is that some callers want to handle it in its own way.
However, some callers don't check it now, which causes unpredictable
result, for example when we have a race between migrating hugepage and
reading /proc/pid/numa_maps. This patch fixes it by adding !pte_present
checks on buggy callbacks.
This bug exists for years and got visible by introducing hugepage migration.
ChangeLog v2:
- fix if condition (check !pte_present() instead of pte_present())
Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Rik van Riel <riel@redhat.com> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Naoya Horiguchi [Wed, 14 May 2014 00:01:36 +0000 (10:01 +1000)]
mempolicy: apply page table walker on queue_pages_range()
queue_pages_range() does page table walking in its own way now, so this
patch rewrites it with walk_page_range(). One difficulty was that
queue_pages_range() needed to check vmas to determine whether we queue
pages from a given vma or skip it. Now we have test_walk() callback in
mm_walk for that purpose, so we can do the replacement cleanly.
queue_pages_test_walk() depends on not only the current vma but also the
previous one, so we use queue_pages->prev to keep it.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Cliff Wickman <cpw@sgi.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Rik van Riel <riel@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Naoya Horiguchi [Wed, 14 May 2014 00:01:36 +0000 (10:01 +1000)]
fs/proc/task_mmu.c: assume non-NULL vma in pagemap_hugetlb()
Fengguang reported smatch error about potential NULL pointer access.
In updated page table walker, we never run ->hugetlb_entry() callback
on the address without vma. This is because __walk_page_range() checks
it in advance. So we can assume non-NULL vma in pagemap_hugetlb().
Naoya Horiguchi [Wed, 14 May 2014 00:01:34 +0000 (10:01 +1000)]
pagemap: redefine callback functions for page table walker
pagemap_pte_range() connected to pmd_entry() does both of pmd loop and pte
loop. So this patch moves pte part into pagemap_pte() on pte_entry().
We remove VM_SOFTDIRTY check in pagemap_pte_range(), because in the new
page table walker we call __walk_page_range() for each vma separately, so
we never experience multiple vmas in single pgd/pud/pmd/pte loop.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Cliff Wickman <cpw@sgi.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Rik van Riel <riel@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Naoya Horiguchi [Wed, 14 May 2014 00:01:34 +0000 (10:01 +1000)]
clear_refs: redefine callback functions for page table walker
Currently clear_refs_pte_range() is connected to pmd_entry() to split thps
if found. But now this work can be done in core page table walker code.
So we have no reason to keep this callback on pmd_entry(). This patch
moves pte handling code on pte_entry() callback.
clear_refs_write() has some prechecks about if we really walk over a given
vma. It's fine to let them done by test_walk() callback, so let's define
it.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Cliff Wickman <cpw@sgi.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Rik van Riel <riel@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Naoya Horiguchi [Wed, 14 May 2014 00:01:34 +0000 (10:01 +1000)]
smaps: redefine callback functions for page table walker
smaps_pte_range() connected to pmd_entry() does both of pmd loop and pte
loop. So this patch moves pte part into smaps_pte() on pte_entry() as
expected by the name.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Cliff Wickman <cpw@sgi.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Rik van Riel <riel@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Naoya Horiguchi [Wed, 14 May 2014 00:01:33 +0000 (10:01 +1000)]
mm/pagewalk.c: fix end address calculation in walk_page_range()
When we try to walk over inside a vma, walk_page_range() tries to walk
until vma->vm_end even if a given end is before that point.
So this patch takes the smaller one as an end address.
Naoya Horiguchi [Wed, 14 May 2014 00:01:33 +0000 (10:01 +1000)]
pagewalk: update page table walker core
This patch updates mm/pagewalk.c to make code less complex and more
maintainable. The basic idea is unchanged and there's no userspace visible
effect.
Most of existing callback functions need access to vma to handle each
entry. So we had better add a new member vma in struct mm_walk instead of
using mm_walk->private, which makes code simpler.
One problem in current page table walker is that we check vma in pgd loop.
Historically this was introduced to support hugetlbfs in the strange
manner. It's better and cleaner to do the vma check outside pgd loop.
Another problem is that many users of page table walker now use only
pmd_entry(), although it does both pmd-walk and pte-walk. This makes code
duplication and fluctuation among callers, which worsens the
maintenability.
One difficulty of code sharing is that the callers want to determine
whether they try to walk over a specific vma or not in their own way. To
solve this, this patch introduces test_walk() callback.
When we try to use multiple callbacks in different levels, skip control is
also important. For example we have thp enabled in normal configuration,
and we are interested in doing some work for a thp. But sometimes we want
to split it and handle as normal pages, and in another time user would
handle both at pmd level and pte level. What we need is that when we've
done pmd_entry() we want to decide whether to go down to pte level
handling based on the pmd_entry()'s result. So this patch introduces a
skip control flag in mm_walk. We can't use the returned value for this
purpose, because we already defined the meaning of whole range of returned
values (>0 is to terminate page table walk in caller's specific manner, =0
is to continue to walk, and <0 is to abort the walk in the general
manner.)
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Cliff Wickman <cpw@sgi.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Rik van Riel <riel@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- add comment on page_size_order()
- use compound_order(compound_head(page)) instead of huge_page_size_order()
- use page_pgoff() in rmap_walk_file() too
- use page_size_order() in kill_proc()
- fix space indent
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- fix wrong shift direction
- introduce page_size_order() and huge_page_size_order()
- move the declaration of PageHuge() to include/linux/hugetlb_inline.h
to avoid macro definition.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Naoya Horiguchi [Wed, 14 May 2014 00:01:32 +0000 (10:01 +1000)]
mm, hugetlbfs: fix rmapping for anonymous hugepages with page_pgoff()
page->index stores pagecache index when the page is mapped into file
mapping region, and the index is in pagecache size unit, so it depends on
the page size. Some of users of reverse mapping obviously assumes that
page->index is in PAGE_CACHE_SHIFT unit, so they don't work for anonymous
hugepage.
For example, consider that we have 3-hugepage vma and try to mbind the 2nd
hugepage to migrate to another node. Then the vma is split and
migrate_page() is called for the 2nd hugepage (belonging to the middle
vma.) In migrate operation, rmap_walk_anon() tries to find the relevant
vma to which the target hugepage belongs, but here we miscalculate pgoff.
So anon_vma_interval_tree_foreach() grabs invalid vma, which fires
VM_BUG_ON.
This patch introduces a new API that is usable both for normal page and
hugepage to get PAGE_SIZE offset from page->index. Users should clearly
distinguish page_index for pagecache index and page_pgoff for page offset.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stephen Rothwell [Wed, 14 May 2014 00:01:32 +0000 (10:01 +1000)]
mm: get rid of __GFP_KMEMCG fix
export kmalloc_order() to modules
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vladimir Davydov [Wed, 14 May 2014 00:01:31 +0000 (10:01 +1000)]
mm: get rid of __GFP_KMEMCG
Currently to allocate a page that should be charged to kmemcg (e.g.
threadinfo), we pass __GFP_KMEMCG flag to the page allocator. The page
allocated is then to be freed by free_memcg_kmem_pages. Apart from
looking asymmetrical, this also requires intrusion to the general
allocation path. So let's introduce separate functions that will
alloc/free pages charged to kmemcg.
The new functions are called alloc_kmem_pages and free_kmem_pages. They
should be used when the caller actually would like to use kmalloc, but has
to fall back to the page allocator for the allocation is large. They only
differ from alloc_pages and free_pages in that besides allocating or
freeing pages they also charge them to the kmem resource counter of the
current memory cgroup.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vladimir Davydov [Wed, 14 May 2014 00:01:31 +0000 (10:01 +1000)]
sl[au]b: charge slabs to kmemcg explicitly
We have only a few places where we actually want to charge kmem so instead
of intruding into the general page allocation path with __GFP_KMEMCG it's
better to explictly charge kmem there. All kmem charges will be easier to
follow that way.
This is a step towards removing __GFP_KMEMCG. It removes __GFP_KMEMCG
from memcg caches' allocflags. Instead it makes slab allocation path call
memcg_charge_kmem directly getting memcg to charge from the cache's memcg
params.
This also eliminates any possibility of misaccounting an allocation going
from one memcg's cache to another memcg, because now we always charge
slabs against the memcg the cache belongs to. That's why this patch
removes the big comment to memcg_kmem_get_cache.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Dave Hansen [Wed, 14 May 2014 00:01:31 +0000 (10:01 +1000)]
mm: slub: fix ALLOC_SLOWPATH stat
There used to be only one path out of __slab_alloc(), and ALLOC_SLOWPATH
got bumped in that exit path. Now there are two, and a bunch of gotos.
ALLOC_SLOWPATH can now get set more than once during a single call to
__slab_alloc() which is pretty bogus. Here's the sequence:
1. Enter __slab_alloc(), fall through all the way to the
stat(s, ALLOC_SLOWPATH);
2. hit 'if (!freelist)', and bump DEACTIVATE_BYPASS, jump to
new_slab (goto #1)
3. Hit 'if (c->partial)', bump CPU_PARTIAL_ALLOC, goto redo
(goto #2)
4. Fall through in the same path we did before all the way to
stat(s, ALLOC_SLOWPATH)
5. bump ALLOC_REFILL stat, then return
Doing this is obviously bogus. It keeps us from being able to accurately
compare ALLOC_SLOWPATH vs. ALLOC_FASTPATH. It also means that the total
number of allocs always exceeds the total number of frees.
This patch moves stat(s, ALLOC_SLOWPATH) to be called from the same place
that __slab_alloc() is. This makes it much less likely that
ALLOC_SLOWPATH will get botched again in the spaghetti-code inside
__slab_alloc().
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Only define count_free() when CONFIG_SLUB_DEBUG since that's the only
context in which it is referenced. Only define count_partial() when
CONFIG_SLUB_DEBUG or CONFIG_SYSFS since the sysfs interface still uses it
for partial slab counts.
Also only define node_nr_objs() when CONFIG_SLUB_DEBUG since that's the
only context in which it is referenced.
Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Wed, 14 May 2014 00:01:30 +0000 (10:01 +1000)]
mm, slab: suppress out of memory warning unless debug is enabled
When the slab or slub allocators cannot allocate additional slab pages,
they emit diagnostic information to the kernel log such as current number
of slabs, number of objects, active objects, etc. This is always coupled
with a page allocation failure warning since it is controlled by
!__GFP_NOWARN.
Suppress this out of memory warning if the allocator is configured without
debug supported. The page allocation failure warning will indicate it is
a failed slab allocation, the order, and the gfp mask, so this is only
useful to diagnose allocator issues.
Since CONFIG_SLUB_DEBUG is already enabled by default for the slub
allocator, there is no functional change with this patch. If debug is
disabled, however, the warnings are now suppressed.
Signed-off-by: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fabian Frederick [Wed, 14 May 2014 00:01:30 +0000 (10:01 +1000)]
mm/slub.c: convert vnsprintf-static to va_format
Inspired by Joe Perches suggestion in ntfs logging clean-up.
Signed-off-by: Fabian Frederick <fabf@skynet.be> Acked-by: Christoph Lameter <cl@linux.com> Cc: Joe Perches <joe@perches.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fabian Frederick [Wed, 14 May 2014 00:01:30 +0000 (10:01 +1000)]
mm/slub.c: convert printk to pr_foo()
-All printk(KERN_foo converted to pr_foo()
-Default printk converted to pr_warn()
-Coalesce format fragments
Signed-off-by: Fabian Frederick <fabf@skynet.be> Acked-by: Christoph Lameter <cl@linux.com> Cc: Joe Perches <joe@perches.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Don Zickus <dzickus@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Aaron Tomlin [Wed, 14 May 2014 00:01:29 +0000 (10:01 +1000)]
nmi: provide the option to issue an NMI back trace to every cpu but current
Sometimes it is preferred not to use the trigger_all_cpu_backtrace()
routine when one wants to avoid capturing a back trace for current. For
instance if one was previously captured recently.
This patch provides a new routine namely
trigger_allbutself_cpu_backtrace() which offers the flexibility to issue
an NMI to every cpu but current and capture a back trace accordingly.
Patch x86 and sparc to support new routine.
[dzickus@redhat.com: add stub in #else clause]
[dzickus@redhat.com: don't print message in single processor case, wrap with get/put_cpu based on Oleg's suggestion] Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fabian Frederick [Wed, 14 May 2014 00:01:29 +0000 (10:01 +1000)]
fs/9p: kerneldoc fixes
Function parameters comment fixing.
Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fabian Frederick [Wed, 14 May 2014 00:01:29 +0000 (10:01 +1000)]
fs/9p/v9fs.c: add __init to v9fs_sysfs_init
v9fs_sysfs_init is only called by __init init_v9fs
Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Josh Hunt [Wed, 14 May 2014 00:01:29 +0000 (10:01 +1000)]
block: restore /proc/partitions to not display non-partitionable removable devices
We found with newer kernels we started seeing the cdrom device showing
up in /proc/partitions, but it was not there before.
Looking into this I found that commit d27769ec ("block: add
GENHD_FL_NO_PART_SCAN") introduces this change in behavior. It's not
clear to me from the commit's changelog if this change was intentional or
not. This comment still remains: /* Don't show non-partitionable
removeable devices or empty devices */ so I've decided to send a patch to
restore the behavior of not printing unpartitionable removable devices.
Signed-off-by: Josh Hunt <johunt@akamai.com> Cc: Tejun Heo <tj@kernel.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In case of error, V2 restored the previous number of segments but left
the BIO_SEG_FLAG set.
To avoid problems, after the page is removed from the bio vec,
V3 performs a recount of the segments in the error code path.
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
bio: modify __bio_add_page() to accept pages that don't start a new segment
The original behaviour is to refuse to add a new page if the maximum
number of segments has been reached, regardless of the fact the page we
are going to add can be merged into the last segment or not.
Unfortunately, when the system runs under heavy memory fragmentation
conditions, a driver may try to add multiple pages to the last segment.
The original code won't accept them and EBUSY will be reported to
userspace.
This patch modifies the function so it refuses to add a page only in case
the latter starts a new segment and the maximum number of segments has
already been reached.
The bug can be easily reproduced with the st driver:
1) set CONFIG_SCSI_MPT2SAS_MAX_SGE or CONFIG_SCSI_MPT3SAS_MAX_SGE to 16
2) modprobe st buffer_kbs=1024
3) #dd if=/dev/zero of=/dev/st0 bs=1M count=10
dd: error writing `/dev/st0': Device or resource busy
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- Invalid maintainer e-mail address:
Mail server reply:
Recipient address rejected: User unknown in virtual alias table
- Remove no longer working webpage URL
- Remove obsolete "Person" field
- Move status to "Orphan"
- Add Dave Jeffery and Jack Hammer to the CREDITS file
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Cc: David Jeffery <dhjeffery@gmail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Paul Bolle <pebolle@tiscali.nl> Reviewed-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
jiangyiwen [Wed, 14 May 2014 00:01:27 +0000 (10:01 +1000)]
ocfs2: manually do the iput once ocfs2_add_entry failed in ocfs2_symlink and ocfs2_mknod
When the call to ocfs2_add_entry() failed in ocfs2_symlink() and
ocfs2_mknod(), iput() will not be called during dput(dentry) because no
d_instantiate(), and this will lead to umount hung.
Signed-off-by: jiangyiwen <jiangyiwen@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
jiangyiwen [Wed, 14 May 2014 00:01:27 +0000 (10:01 +1000)]
ocfs2: do not return DLM_MIGRATE_RESPONSE_MASTERY_REF to avoid endless,loop during umount
The following case may lead to endless loop during umount.
node A node B node C node D
umount volume,
migrate lockres1
to B
want to lock lockres1,
send
MASTER_REQUEST_MSG
to C
init block mle
send
MIGRATE_REQUEST_MSG
to C
find a block
mle, and then
return
DLM_MIGRATE_RESPONSE_MASTERY_REF
to B
set C in refmap
umount successfully
try to umount, endless
loop occurs when migrate
lockres1 since C is in
refmap
So we can fix this endless loop case by only returning
DLM_MIGRATE_RESPONSE_MASTERY_REF if it has a mastery mle when receiving
MIGRATE_REQUEST_MSG.
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: jiangyiwen <jiangyiwen@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Xue jiufei <xuejiufei@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Yiwen Jiang [Wed, 14 May 2014 00:01:27 +0000 (10:01 +1000)]
ocfs2: fix a tiny race when running dirop_fileop_racer
When running dirop_fileop_racer we found a dead lock case.
2 nodes, say Node A and Node B, mount the same ocfs2 volume. Create
/race/16/1 in the filesystem, and let the inode number of dir 16 is less
than the inode number of dir race.
Node A Node B
mv /race/16/1 /race/
right after Node A has got the
EX mode of /race/16/, and tries to
get EX mode of /race
ls /race/16/
In this case, Node A has got the EX mode of /race/16/, and wants to get EX
mode of /race/. Node B has got the PR mode of /race/, and wants to get
the PR mode of /race/16/. Since EX and PR are mutually exclusive, dead
lock happens.
This patch fixes this case by locking in ancestor order before trying
inode number order.
Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com> Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When o2net-accept-one() rejects an illegal connection, it terminates the
loop picking up the remaining queued connections. This fix will continue
accepting connections till the queue is emtpy.
Signed-off-by: Tariq Saseed <tariq.x.saeed@oracle.com> Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tariq Saeed [Wed, 14 May 2014 00:01:26 +0000 (10:01 +1000)]
ocfs2/o2net: incorrect to terminate accepting connections loop upon rejecting an invalid one
When o2net-accept-one() rejects an illegal connection, it terminates the
loop picking up the remaining queued connections. This fix will continue
accepting connections till the queue is emtpy.
alex chen [Wed, 14 May 2014 00:01:26 +0000 (10:01 +1000)]
ocfs2: should add inode into orphan dir after updating entry in ocfs2_rename()
There are two files a and b in dir /mnt/ocfs2.
node A node B
mv a b
In ocfs2_rename(), after calling
ocfs2_orphan_add(), the inode of
file b will be added into orphan
dir.
If ocfs2_update_entry() fails,
ocfs2_rename return error and mv
operation fails. But file b still
exists in the parent dir.
ocfs2_queue_orphan_scan
-> ocfs2_queue_recovery_completion
-> ocfs2_complete_recovery
-> ocfs2_recover_orphans
The inode of the file b will be
put with iput().
ocfs2_evict_inode
-> ocfs2_delete_inode
-> ocfs2_wipe_inode
-> ocfs2_remove_inode
OCFS2_VALID_FL in the inode
i_flags will be cleared.
The file b still can be accessed
on node B.
ls /mnt/ocfs2
When first read the file b with
ocfs2_read_inode_block(). It will
validate the inode using
ocfs2_validate_inode_block().
Because OCFS2_VALID_FL not set in
the inode i_flags, so the file
system will be readonly.
So we should add inode into orphan dir after updating entry in
ocfs2_rename().
Signed-off-by: alex.chen <alex.chen@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Andrew Morton [Wed, 14 May 2014 00:01:26 +0000 (10:01 +1000)]
ocfs2-limit-printk-when-journal-is-aborted-fix
document the msleep
Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Joseph Qi [Wed, 14 May 2014 00:01:26 +0000 (10:01 +1000)]
ocfs2: limit printk when journal is aborted
Once JBD2_ABORT is set, ocfs2_commit_cache will fail in
ocfs2_commit_thread. Then it will get into a loop with mass logs. This
will meaninglessly consume a larger number of resource and may lead to the
system hanging. So limit printk in this case.
Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
George Spelvin [Wed, 14 May 2014 00:01:25 +0000 (10:01 +1000)]
ocfs2: remove some redundant casting
There are two standard techniques for dereferencing structures pointed
to by void *: cast to the right type each time they're used, or assign
to local variables of the right type.
But there's no need to do *both*.
Signed-off-by: George Spelvin <linux@horizon.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fabian Frederick [Wed, 14 May 2014 00:01:25 +0000 (10:01 +1000)]
fs/ocfs2/super.c: use OCFS2_MAX_VOL_LABEL_LEN and strlcpy
Replace strncpy(size 63) by defined value.
Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fabian Frederick [Wed, 14 May 2014 00:01:25 +0000 (10:01 +1000)]
ocfs2: remove NULL assignments on static
Static values are automatically initialized to NULL.
Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
projects / karo-tx-linux.git / log