Commit Graph

8123 Commits

Author SHA1 Message Date
Luiz Capitulino
2906dd5283 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:

 # echo 2 > \
   /sys/devices/system/node/node1/hugepages/hugepages-1048576kB/nr_hugepages

And, to release all gigantic pages on the same node:

 # echo 0 > \
   /sys/devices/system/node/node1/hugepages/hugepages-1048576kB/nr_hugepages

Please, refer to patch 5/5 for full technical details.

Finally, please note that this series is a follow up for a previous series
that tried to extend the command-line options set to be NUMA aware:

 http://marc.info/?l=linux-mm&m=139593335312191&w=2

During the discussion of that series it was agreed that having runtime
allocation support for gigantic pages was a better solution.

This patch (of 5):

This function is going to be used by non-init code in a future
commit.

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>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:58 -07:00
Duan Jiong
14bd5b458b mm/mmap.c: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
Fix a coccinelle error regarding usage of IS_ERR and PTR_ERR instead of
PTR_ERR_OR_ZERO.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:58 -07:00
Vladimir Davydov
cea371f4f3 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:58 -07:00
Johannes Weiner
3dae7fec5e 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:58 -07:00
Sebastian Ott
8bf8fcb076 mm/mempool: warn about __GFP_ZERO usage
Memory obtained via mempool_alloc is not always zeroed even when
called with __GFP_ZERO. Add a note and VM_BUG_ON statement to make
that clear.

[akpm@linux-foundation.org: use VM_WARN_ON_ONCE]
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:58 -07:00
Andrew Morton
ae3a8c1c23 mm/huge_memory.c: complete conversion to pr_foo()
It was using a mix of pr_foo() and printk(KERN_ERR ...).

Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:58 -07:00
Kirill A. Shutemov
ff9e43eb4f 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:57 -07:00
Akinobu Mita
2bfc2862c4 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:57 -07:00
Davidlohr Bueso
6b4ebc3a90 mm,vmacache: optimize overflow system-wide flushing
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.

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:57 -07:00
Davidlohr Bueso
4f115147ff mm,vmacache: add debug data
Introduce a CONFIG_DEBUG_VM_VMACACHE option to enable counting the cache
hit rate -- exported in /proc/vmstat.

Any updates to the caching scheme needs this kind of data, thus it can
save some work re-implementing the counting all the time.

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:57 -07:00
Suleiman Souhlal
6f04f48dc9 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:56 -07:00
Cyrill Gorcunov
b43790eedd 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:56 -07:00
Cyrill Gorcunov
0bf073315c 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:56 -07:00
Vladimir Davydov
52383431b3 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.

[sfr@canb.auug.org.au: export kmalloc_order() to modules]
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: 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: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:56 -07:00
Vladimir Davydov
5dfb417509 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>
Acked-by: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:56 -07:00
Dave Hansen
8eae149267 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:56 -07:00
David Rientjes
9a02d69993 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:56 -07:00
Fabian Frederick
ecc42fbe95 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:55 -07:00
Fabian Frederick
f9f5828594 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: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:55 -07:00
Mel Gorman
c46a7c817e x86: define _PAGE_NUMA by reusing software bits on the PMD and PTE levels
_PAGE_NUMA is currently an alias of _PROT_PROTNONE to trap NUMA hinting
faults on x86.  Care is taken such that _PAGE_NUMA is used only in
situations where the VMA flags distinguish between NUMA hinting faults
and prot_none faults.  This decision was x86-specific and conceptually
it is difficult requiring special casing to distinguish between PROTNONE
and NUMA ptes based on context.

Fundamentally, we only need the _PAGE_NUMA bit to tell the difference
between an entry that is really unmapped and a page that is protected
for NUMA hinting faults as if the PTE is not present then a fault will
be trapped.

Swap PTEs on x86-64 use the bits after _PAGE_GLOBAL for the offset.
This patch shrinks the maximum possible swap size and uses the bit to
uniquely distinguish between NUMA hinting ptes and swap ptes.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Noonan <steven@uplinklabs.net>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:55 -07:00
Naoya Horiguchi
c177c81e09 hugetlb: restrict hugepage_migration_support() to x86_64
Currently hugepage migration is available for all archs which support
pmd-level hugepage, but testing is done only for x86_64 and there're
bugs for other archs.  So to avoid breaking such archs, this patch
limits the availability strictly to x86_64 until developers of other
archs get interested in enabling this feature.

Simply disabling hugepage migration on non-x86_64 archs is not enough to
fix the reported problem where sys_move_pages() hits the BUG_ON() in
follow_page(FOLL_GET), so let's fix this by checking if hugepage
migration is supported in vma_migratable().

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: <stable@vger.kernel.org>	[3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:51 -07:00
Hugh Dickins
7f39dda9d8 mm: fix sleeping function warning from __put_anon_vma
Trinity reports BUG:

  sleeping function called from invalid context at kernel/locking/rwsem.c:47
  in_atomic(): 0, irqs_disabled(): 0, pid: 5787, name: trinity-c27

__might_sleep < down_write < __put_anon_vma < page_get_anon_vma <
migrate_pages < compact_zone < compact_zone_order < try_to_compact_pages ..

Right, since conversion to mutex then rwsem, we should not put_anon_vma()
from inside an rcu_read_lock()ed section: fix the two places that did so.
And add might_sleep() to anon_vma_free(), as suggested by Peter Zijlstra.

Fixes: 88c22088bf ("mm: optimize page_lock_anon_vma() fast-path")
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:51 -07:00
Linus Torvalds
1aacb90eaa Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next
Pull trivial tree changes from Jiri Kosina:
 "Usual pile of patches from trivial tree that make the world go round"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (23 commits)
  staging: go7007: remove reference to CONFIG_KMOD
  aic7xxx: Remove obsolete preprocessor define
  of: dma: doc fixes
  doc: fix incorrect formula to calculate CommitLimit value
  doc: Note need of bc in the kernel build from 3.10 onwards
  mm: Fix printk typo in dmapool.c
  modpost: Fix comment typo "Modules.symvers"
  Kconfig.debug: Grammar s/addition/additional/
  wimax: Spelling s/than/that/, wording s/destinatary/recipient/
  aic7xxx: Spelling s/termnation/termination/
  arm64: mm: Remove superfluous "the" in comment
  of: Spelling s/anonymouns/anonymous/
  dma: imx-sdma: Spelling s/determnine/determine/
  ath10k: Improve grammar in comments
  ath6kl: Spelling s/determnine/determine/
  of: Improve grammar for of_alias_get_id() documentation
  drm/exynos: Spelling s/contro/control/
  radio-bcm2048.c: fix wrong overflow check
  doc: printk-formats: do not mention casts for u64/s64
  doc: spelling error changes
  ...
2014-06-04 08:50:34 -07:00
Linus Torvalds
c84a1e32ee Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull scheduler updates from Ingo Molnar:
 "The main scheduling related changes in this cycle were:

   - various sched/numa updates, for better performance

   - tree wide cleanup of open coded nice levels

   - nohz fix related to rq->nr_running use

   - cpuidle changes and continued consolidation to improve the
     kernel/sched/idle.c high level idle scheduling logic.  As part of
     this effort I pulled cpuidle driver changes from Rafael as well.

   - standardized idle polling amongst architectures

   - continued work on preparing better power/energy aware scheduling

   - sched/rt updates

   - misc fixlets and cleanups"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits)
  sched/numa: Decay ->wakee_flips instead of zeroing
  sched/numa: Update migrate_improves/degrades_locality()
  sched/numa: Allow task switch if load imbalance improves
  sched/rt: Fix 'struct sched_dl_entity' and dl_task_time() comments, to match the current upstream code
  sched: Consolidate open coded implementations of nice level frobbing into nice_to_rlimit() and rlimit_to_nice()
  sched: Initialize rq->age_stamp on processor start
  sched, nohz: Change rq->nr_running to always use wrappers
  sched: Fix the rq->next_balance logic in rebalance_domains() and idle_balance()
  sched: Use clamp() and clamp_val() to make sys_nice() more readable
  sched: Do not zero sg->cpumask and sg->sgp->power in build_sched_groups()
  sched/numa: Fix initialization of sched_domain_topology for NUMA
  sched: Call select_idle_sibling() when not affine_sd
  sched: Simplify return logic in sched_read_attr()
  sched: Simplify return logic in sched_copy_attr()
  sched: Fix exec_start/task_hot on migrated tasks
  arm64: Remove TIF_POLLING_NRFLAG
  metag: Remove TIF_POLLING_NRFLAG
  sched/idle: Make cpuidle_idle_call() void
  sched/idle: Reflow cpuidle_idle_call()
  sched/idle: Delay clearing the polling bit
  ...
2014-06-03 14:00:15 -07:00
Linus Torvalds
776edb5931 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull core locking updates from Ingo Molnar:
 "The main changes in this cycle were:

   - reduced/streamlined smp_mb__*() interface that allows more usecases
     and makes the existing ones less buggy, especially in rarer
     architectures

   - add rwsem implementation comments

   - bump up lockdep limits"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  rwsem: Add comments to explain the meaning of the rwsem's count field
  lockdep: Increase static allocations
  arch: Mass conversion of smp_mb__*()
  arch,doc: Convert smp_mb__*()
  arch,xtensa: Convert smp_mb__*()
  arch,x86: Convert smp_mb__*()
  arch,tile: Convert smp_mb__*()
  arch,sparc: Convert smp_mb__*()
  arch,sh: Convert smp_mb__*()
  arch,score: Convert smp_mb__*()
  arch,s390: Convert smp_mb__*()
  arch,powerpc: Convert smp_mb__*()
  arch,parisc: Convert smp_mb__*()
  arch,openrisc: Convert smp_mb__*()
  arch,mn10300: Convert smp_mb__*()
  arch,mips: Convert smp_mb__*()
  arch,metag: Convert smp_mb__*()
  arch,m68k: Convert smp_mb__*()
  arch,m32r: Convert smp_mb__*()
  arch,ia64: Convert smp_mb__*()
  ...
2014-06-03 12:57:53 -07:00
Linus Torvalds
8f5759aeb8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux into next
Pull first set of s390 updates from Martin Schwidefsky:
 "The biggest change in this patchset is conversion from the bootmem
  bitmaps to the memblock code.  This conversion requires two common
  code patches to introduce the 'physmem' memblock list.

  We experimented with ticket spinlocks but in the end decided against
  them as they perform poorly on virtualized systems.  But the spinlock
  cleanup and some small improvements are included.

  The uaccess code got another optimization, the get_user/put_user calls
  are now inline again for kernel compiles targeted at z10 or newer
  machines.  This makes the text segment shorter and the code gets a
  little bit faster.

  And as always some bug fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (31 commits)
  s390/lowcore: replace lowcore irb array with a per-cpu variable
  s390/lowcore: reserve 96 bytes for IRB in lowcore
  s390/facilities: remove extract-cpu-time facility check
  s390: require mvcos facility for z10 and newer machines
  s390/boot: fix boot of compressed kernel built with gcc 4.9
  s390/cio: remove weird assignment during argument evaluation
  s390/time: cast tv_nsec to u64 prior to shift in update_vsyscall
  s390/oprofile: make return of 0 explicit
  s390/spinlock: refactor arch_spin_lock_wait[_flags]
  s390/rwlock: add missing local_irq_restore calls
  s390/spinlock,rwlock: always to a load-and-test first
  s390/cio: fix multiple structure definitions
  s390/spinlock: fix system hang with spin_retry <= 0
  s390/appldata: add slab.h for kzalloc/kfree
  s390/uaccess: provide inline variants of get_user/put_user
  s390/pci: add some new arch specific pci attributes
  s390/pci: use pdev->dev.groups for attribute creation
  s390/pci: use macro for attribute creation
  s390/pci: improve state check when processing hotplug events
  s390: split TIF bits into CIF, PIF and TIF bits
  ...
2014-06-03 10:26:41 -07:00
Linus Torvalds
681a289548 Merge branch 'for-3.16/core' of git://git.kernel.dk/linux-block into next
Pull block core updates from Jens Axboe:
 "It's a big(ish) round this time, lots of development effort has gone
  into blk-mq in the last 3 months.  Generally we're heading to where
  3.16 will be a feature complete and performant blk-mq.  scsi-mq is
  progressing nicely and will hopefully be in 3.17.  A nvme port is in
  progress, and the Micron pci-e flash driver, mtip32xx, is converted
  and will be sent in with the driver pull request for 3.16.

  This pull request contains:

   - Lots of prep and support patches for scsi-mq have been integrated.
     All from Christoph.

   - API and code cleanups for blk-mq from Christoph.

   - Lots of good corner case and error handling cleanup fixes for
     blk-mq from Ming Lei.

   - A flew of blk-mq updates from me:

     * Provide strict mappings so that the driver can rely on the CPU
       to queue mapping.  This enables optimizations in the driver.

     * Provided a bitmap tagging instead of percpu_ida, which never
       really worked well for blk-mq.  percpu_ida relies on the fact
       that we have a lot more tags available than we really need, it
       fails miserably for cases where we exhaust (or are close to
       exhausting) the tag space.

     * Provide sane support for shared tag maps, as utilized by scsi-mq

     * Various fixes for IO timeouts.

     * API cleanups, and lots of perf tweaks and optimizations.

   - Remove 'buffer' from struct request.  This is ancient code, from
     when requests were always virtually mapped.  Kill it, to reclaim
     some space in struct request.  From me.

   - Remove 'magic' from blk_plug.  Since we store these on the stack
     and since we've never caught any actual bugs with this, lets just
     get rid of it.  From me.

   - Only call part_in_flight() once for IO completion, as includes two
     atomic reads.  Hopefully we'll get a better implementation soon, as
     the part IO stats are now one of the more expensive parts of doing
     IO on blk-mq.  From me.

   - File migration of block code from {mm,fs}/ to block/.  This
     includes bio.c, bio-integrity.c, bounce.c, and ioprio.c.  From me,
     from a discussion on lkml.

  That should describe the meat of the pull request.  Also has various
  little fixes and cleanups from Dave Jones, Shaohua Li, Duan Jiong,
  Fengguang Wu, Fabian Frederick, Randy Dunlap, Robert Elliott, and Sam
  Bradshaw"

* 'for-3.16/core' of git://git.kernel.dk/linux-block: (100 commits)
  blk-mq: push IPI or local end_io decision to __blk_mq_complete_request()
  blk-mq: remember to start timeout handler for direct queue
  block: ensure that the timer is always added
  blk-mq: blk_mq_unregister_hctx() can be static
  blk-mq: make the sysfs mq/ layout reflect current mappings
  blk-mq: blk_mq_tag_to_rq should handle flush request
  block: remove dead code in scsi_ioctl:blk_verify_command
  blk-mq: request initialization optimizations
  block: add queue flag for disabling SG merging
  block: remove 'magic' from struct blk_plug
  blk-mq: remove alloc_hctx and free_hctx methods
  blk-mq: add file comments and update copyright notices
  blk-mq: remove blk_mq_alloc_request_pinned
  blk-mq: do not use blk_mq_alloc_request_pinned in blk_mq_map_request
  blk-mq: remove blk_mq_wait_for_tags
  blk-mq: initialize request in __blk_mq_alloc_request
  blk-mq: merge blk_mq_alloc_reserved_request into blk_mq_alloc_request
  blk-mq: add helper to insert requests from irq context
  blk-mq: remove stale comment for blk_mq_complete_request()
  blk-mq: allow non-softirq completions
  ...
2014-06-02 09:29:34 -07:00
Naoya Horiguchi
3e030ecc0f mm/memory-failure.c: fix memory leak by race between poison and unpoison
When a memory error happens on an in-use page or (free and in-use)
hugepage, the victim page is isolated with its refcount set to one.

When you try to unpoison it later, unpoison_memory() calls put_page()
for it twice in order to bring the page back to free page pool (buddy or
free hugepage list).  However, if another memory error occurs on the
page which we are unpoisoning, memory_failure() returns without
releasing the refcount which was incremented in the same call at first,
which results in memory leak and unconsistent num_poisoned_pages
statistics.  This patch fixes it.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: <stable@vger.kernel.org>    [2.6.32+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-23 09:37:30 -07:00
Michal Hocko
6f6acb0051 memcg: fix swapcache charge from kernel thread context
Commit 284f39afea ("mm: memcg: push !mm handling out to page cache
charge function") explicitly checks for page cache charges without any
mm context (from kernel thread context[1]).

This seemed to be the only possible case where memory could be charged
without mm context so commit 03583f1a63 ("memcg: remove unnecessary
!mm check from try_get_mem_cgroup_from_mm()") removed the mm check from
get_mem_cgroup_from_mm().  This however caused another NULL ptr
dereference during early boot when loopback kernel thread splices to
tmpfs as reported by Stephan Kulow:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000360
  IP: get_mem_cgroup_from_mm.isra.42+0x2b/0x60
  Oops: 0000 [#1] SMP
  Modules linked in: btrfs dm_multipath dm_mod scsi_dh multipath raid10 raid456 async_raid6_recov async_memcpy async_pq raid6_pq async_xor xor async_tx raid1 raid0 md_mod parport_pc parport nls_utf8 isofs usb_storage iscsi_ibft iscsi_boot_sysfs arc4 ecb fan thermal nfs lockd fscache nls_iso8859_1 nls_cp437 sg st hid_generic usbhid af_packet sunrpc sr_mod cdrom ata_generic uhci_hcd virtio_net virtio_blk ehci_hcd usbcore ata_piix floppy processor button usb_common virtio_pci virtio_ring virtio edd squashfs loop ppa]
  CPU: 0 PID: 97 Comm: loop1 Not tainted 3.15.0-rc5-5-default #1
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  Call Trace:
    __mem_cgroup_try_charge_swapin+0x40/0xe0
    mem_cgroup_charge_file+0x8b/0xd0
    shmem_getpage_gfp+0x66b/0x7b0
    shmem_file_splice_read+0x18f/0x430
    splice_direct_to_actor+0xa2/0x1c0
    do_lo_receive+0x5a/0x60 [loop]
    loop_thread+0x298/0x720 [loop]
    kthread+0xc6/0xe0
    ret_from_fork+0x7c/0xb0

Also Branimir Maksimovic reported the following oops which is tiggered
for the swapcache charge path from the accounting code for kernel threads:

  CPU: 1 PID: 160 Comm: kworker/u8:5 Tainted: P           OE 3.15.0-rc5-core2-custom #159
  Hardware name: System manufacturer System Product Name/MAXIMUSV GENE, BIOS 1903 08/19/2013
  task: ffff880404e349b0 ti: ffff88040486a000 task.ti: ffff88040486a000
  RIP: get_mem_cgroup_from_mm.isra.42+0x2b/0x60
  Call Trace:
    __mem_cgroup_try_charge_swapin+0x45/0xf0
    mem_cgroup_charge_file+0x9c/0xe0
    shmem_getpage_gfp+0x62c/0x770
    shmem_write_begin+0x38/0x40
    generic_perform_write+0xc5/0x1c0
    __generic_file_aio_write+0x1d1/0x3f0
    generic_file_aio_write+0x4f/0xc0
    do_sync_write+0x5a/0x90
    do_acct_process+0x4b1/0x550
    acct_process+0x6d/0xa0
    do_exit+0x827/0xa70
    kthread+0xc3/0xf0

This patch fixes the issue by reintroducing mm check into
get_mem_cgroup_from_mm.  We could do the same trick in
__mem_cgroup_try_charge_swapin as we do for the regular page cache path
but it is not worth troubles.  The check is not that expensive and it is
better to have get_mem_cgroup_from_mm more robust.

[1] - http://marc.info/?l=linux-mm&m=139463617808941&w=2

Fixes: 03583f1a63 ("memcg: remove unnecessary !mm check from try_get_mem_cgroup_from_mm()")
Reported-and-tested-by: Stephan Kulow <coolo@suse.com>
Reported-by: Branimir Maksimovic <branimir.maksimovic@gmail.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-23 09:37:29 -07:00
Johannes Weiner
55231e5c89 mm: madvise: fix MADV_WILLNEED on shmem swapouts
MADV_WILLNEED currently does not read swapped out shmem pages back in.

Commit 0cd6144aad ("mm + fs: prepare for non-page entries in page
cache radix trees") made find_get_page() filter exceptional radix tree
entries but failed to convert all find_get_page() callers that WANT
exceptional entries over to find_get_entry().  One of them is shmem swap
readahead in madvise, which now skips over any swap-out records.

Convert it to find_get_entry().

Fixes: 0cd6144aad ("mm + fs: prepare for non-page entries in page cache radix trees")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-23 09:37:29 -07:00
Jens Axboe
7fcbbaf183 mm/filemap.c: avoid always dirtying mapping->flags on O_DIRECT
In some testing I ran today (some fio jobs that spread over two nodes),
we end up spending 40% of the time in filemap_check_errors().  That
smells fishy.  Looking further, this is basically what happens:

blkdev_aio_read()
    generic_file_aio_read()
        filemap_write_and_wait_range()
            if (!mapping->nr_pages)
                filemap_check_errors()

and filemap_check_errors() always attempts two test_and_clear_bit() on
the mapping flags, thus dirtying it for every single invocation.  The
patch below tests each of these bits before clearing them, avoiding this
issue.  In my test case (4-socket box), performance went from 1.7M IOPS
to 4.0M IOPS.

Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-23 09:37:29 -07:00
Chen Yucong
b985194c8c hwpoison, hugetlb: lock_page/unlock_page does not match for handling a free hugepage
For handling a free hugepage in memory failure, the race will happen if
another thread hwpoisoned this hugepage concurrently.  So we need to
check PageHWPoison instead of !PageHWPoison.

If hwpoison_filter(p) returns true or a race happens, then we need to
unlock_page(hpage).

Signed-off-by: Chen Yucong <slaoub@gmail.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Tested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: <stable@vger.kernel.org>	[2.6.36+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-23 09:37:29 -07:00
Ingo Molnar
65c2ce7004 Linux 3.15-rc6
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Merge tag 'v3.15-rc6' into sched/core, to pick up the latest fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22 10:28:56 +02:00
Philipp Hachtmann
70210ed950 mm/memblock: add physical memory list
Add the physmem list to the memblock structure. This list only exists
if HAVE_MEMBLOCK_PHYS_MAP is selected and contains the unmodified
list of physically available memory. It differs from the memblock
memory list as it always contains all memory ranges even if the
memory has been restricted, e.g. by use of the mem= kernel parameter.

Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-05-20 08:58:39 +02:00
Philipp Hachtmann
f1af9d3af3 mm/memblock: Do some refactoring, enhance API
Refactor the memblock code and extend the memblock API to make it
more flexible. With the extended API it is simple to define and
work with additional memory lists.

The static functions memblock_add_region and __memblock_remove are
renamed to memblock_add_range and meblock_remove_range and added to
the memblock API.

The __next_free_mem_range and __next_free_mem_range_rev functions
are replaced with calls to the more generic list walkers
__next_mem_range and __next_mem_range_rev.

To walk an arbitrary memory list two new macros for_each_mem_range
and for_each_mem_range_rev are added. These new macros are used
to define for_each_free_mem_range and for_each_free_mem_range_reverse.

Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-05-20 08:58:39 +02:00
Linus Torvalds
41abc90228 Metag architecture and related fixes for v3.15
Mostly fixes for metag and parisc relating to upgrowing stacks.
 
 * Fix missing compiler barriers in metag memory barriers.
 * Fix BUG_ON on metag when RLIMIT_STACK hard limit is increased beyond
   safe value.
 * Make maximum stack size configurable. This reduces the default user
   stack size back to 80MB (especially on parisc after their removal of
   _STK_LIM_MAX override). This only affects metag and parisc.
 * Remove metag _STK_LIM_MAX override to match other arches and follow
   parisc, now that it is safe to do so (due to the BUG_ON fix mentioned
   above).
 * Finally now that both metag and parisc _STK_LIM_MAX overrides have
   been removed, it makes sense to remove _STK_LIM_MAX altogether.
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Merge tag 'metag-for-v3.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag

Pull Metag architecture and related fixes from James Hogan:
 "Mostly fixes for metag and parisc relating to upgrowing stacks.

   - Fix missing compiler barriers in metag memory barriers.
   - Fix BUG_ON on metag when RLIMIT_STACK hard limit is increased
     beyond safe value.
   - Make maximum stack size configurable.  This reduces the default
     user stack size back to 80MB (especially on parisc after their
     removal of _STK_LIM_MAX override).  This only affects metag and
     parisc.
   - Remove metag _STK_LIM_MAX override to match other arches and follow
     parisc, now that it is safe to do so (due to the BUG_ON fix
     mentioned above).
   - Finally now that both metag and parisc _STK_LIM_MAX overrides have
     been removed, it makes sense to remove _STK_LIM_MAX altogether"

* tag 'metag-for-v3.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag:
  asm-generic: remove _STK_LIM_MAX
  metag: Remove _STK_LIM_MAX override
  parisc,metag: Do not hardcode maximum userspace stack size
  metag: Reduce maximum stack size to 256MB
  metag: fix memory barriers
2014-05-20 14:30:34 +09:00
Jens Axboe
719c555f44 block: move mm/bounce.c to block/
Continue moving some of the block files that are scattered around.
bounce.c contains only code for bouncing the contents of a bio.
It's block proper code, not mm code.

Suggested-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-19 20:01:52 -06:00
Helge Deller
042d27acb6 parisc,metag: Do not hardcode maximum userspace stack size
This patch affects only architectures where the stack grows upwards
(currently parisc and metag only). On those do not hardcode the maximum
initial stack size to 1GB for 32-bit processes, but make it configurable
via a config option.

The main problem with the hardcoded stack size is, that we have two
memory regions which grow upwards: stack and heap. To keep most of the
memory available for heap in a flexmap memory layout, it makes no sense
to hard allocate up to 1GB of the memory for stack which can't be used
as heap then.

This patch makes the stack size for 32-bit processes configurable and
uses 80MB as default value which has been in use during the last few
years on parisc and which hasn't showed any problems yet.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: linux-parisc@vger.kernel.org
Cc: linux-metag@vger.kernel.org
Cc: John David Anglin <dave.anglin@bell.net>
2014-05-15 00:01:41 +01:00
Linus Torvalds
68cb363a4d Merge branch 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull a percpu fix from Tejun Heo:
 "Fix for a percpu allocator bug where it could try to kfree() a memory
  region allocated using vmalloc().  The bug has been there for years
  now and is unlikely to have ever triggered given the size of struct
  pcpu_chunk.  It's still theoretically possible and the fix is simple
  and safe enough, so the patch is marked with -stable"

* 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: make pcpu_alloc_chunk() use pcpu_mem_free() instead of kfree()
2014-05-13 11:25:56 +09:00
Kirill A. Shutemov
dd18dbc2d4 mm, thp: close race between mremap() and split_huge_page()
It's critical for split_huge_page() (and migration) to catch and freeze
all PMDs on rmap walk.  It gets tricky if there's concurrent fork() or
mremap() since usually we copy/move page table entries on dup_mm() or
move_page_tables() without rmap lock taken.  To get it work we rely on
rmap walk order to not miss any entry.  We expect to see destination VMA
after source one to work correctly.

But after switching rmap implementation to interval tree it's not always
possible to preserve expected walk order.

It works fine for dup_mm() since new VMA has the same vma_start_pgoff()
/ vma_last_pgoff() and explicitly insert dst VMA after src one with
vma_interval_tree_insert_after().

But on move_vma() destination VMA can be merged into adjacent one and as
result shifted left in interval tree.  Fortunately, we can detect the
situation and prevent race with rmap walk by moving page table entries
under rmap lock.  See commit 38a76013ad.

Problem is that we miss the lock when we move transhuge PMD.  Most
likely this bug caused the crash[1].

[1] http://thread.gmane.org/gmane.linux.kernel.mm/96473

Fixes: 108d6642ad ("mm anon rmap: remove anon_vma_moveto_tail")

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Michel Lespinasse <walken@google.com>
Cc: Dave Jones <davej@redhat.com>
Cc: David Miller <davem@davemloft.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>        [3.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-11 17:55:48 +09:00
Catalin Marinas
3551a9280b mm: postpone the disabling of kmemleak early logging
Commit 8910ae896c ("kmemleak: change some global variables to int"),
in addition to the atomic -> int conversion, moved the disabling of
kmemleak_early_log to the beginning of the kmemleak_init() function,
before the full kmemleak tracing is actually enabled.  In this small
window, kmem_cache_create() is called by kmemleak which triggers
additional memory allocation that are not traced.  This patch restores
the original logic with kmemleak_early_log disabling when kmemleak is
fully functional.

Fixes: 8910ae896c (kmemleak: change some global variables to int)

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Li Zefan <lizefan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-11 17:55:48 +09:00
Rik van Riel
107437febd mm/numa: Remove BUG_ON() in __handle_mm_fault()
Changing PTEs and PMDs to pte_numa & pmd_numa is done with the
mmap_sem held for reading, which means a pmd can be instantiated
and turned into a numa one while __handle_mm_fault() is examining
the value of old_pmd.

If that happens, __handle_mm_fault() should just return and let
the page fault retry, instead of throwing an oops. This is
handled by the test for pmd_trans_huge(*pmd) below.

Signed-off-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Sunil Pandey <sunil.k.pandey@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: linux-mm@kvack.org
Cc: lwoodman@redhat.com
Cc: dave.hansen@intel.com
Link: http://lkml.kernel.org/r/20140429153615.2d72098e@annuminas.surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07 13:33:48 +02:00
Ingo Molnar
2fe5de9ce7 Merge branch 'sched/urgent' into sched/core, to avoid conflicts
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07 13:15:46 +02:00
Linus Torvalds
38583f095c Merge branch 'akpm' (incoming from Andrew)
Merge misc fixes from Andrew Morton:
 "13 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  agp: info leak in agpioc_info_wrap()
  fs/affs/super.c: bugfix / double free
  fanotify: fix -EOVERFLOW with large files on 64-bit
  slub: use sysfs'es release mechanism for kmem_cache
  revert "mm: vmscan: do not swap anon pages just because free+file is low"
  autofs: fix lockref lookup
  mm: filemap: update find_get_pages_tag() to deal with shadow entries
  mm/compaction: make isolate_freepages start at pageblock boundary
  MAINTAINERS: zswap/zbud: change maintainer email address
  mm/page-writeback.c: fix divide by zero in pos_ratio_polynom
  hugetlb: ensure hugepage access is denied if hugepages are not supported
  slub: fix memcg_propagate_slab_attrs
  drivers/rtc/rtc-pcf8523.c: fix month definition
2014-05-06 13:07:41 -07:00
Christoph Lameter
41a212859a slub: use sysfs'es release mechanism for kmem_cache
debugobjects warning during netfilter exit:

    ------------[ cut here ]------------
    WARNING: CPU: 6 PID: 4178 at lib/debugobjects.c:260 debug_print_object+0x8d/0xb0()
    ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x20
    Modules linked in:
    CPU: 6 PID: 4178 Comm: kworker/u16:2 Tainted: G        W 3.11.0-next-20130906-sasha #3984
    Workqueue: netns cleanup_net
    Call Trace:
      dump_stack+0x52/0x87
      warn_slowpath_common+0x8c/0xc0
      warn_slowpath_fmt+0x46/0x50
      debug_print_object+0x8d/0xb0
      __debug_check_no_obj_freed+0xa5/0x220
      debug_check_no_obj_freed+0x15/0x20
      kmem_cache_free+0x197/0x340
      kmem_cache_destroy+0x86/0xe0
      nf_conntrack_cleanup_net_list+0x131/0x170
      nf_conntrack_pernet_exit+0x5d/0x70
      ops_exit_list+0x5e/0x70
      cleanup_net+0xfb/0x1c0
      process_one_work+0x338/0x550
      worker_thread+0x215/0x350
      kthread+0xe7/0xf0
      ret_from_fork+0x7c/0xb0

Also during dcookie cleanup:

    WARNING: CPU: 12 PID: 9725 at lib/debugobjects.c:260 debug_print_object+0x8c/0xb0()
    ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x20
    Modules linked in:
    CPU: 12 PID: 9725 Comm: trinity-c141 Not tainted 3.15.0-rc2-next-20140423-sasha-00018-gc4ff6c4 #408
    Call Trace:
      dump_stack (lib/dump_stack.c:52)
      warn_slowpath_common (kernel/panic.c:430)
      warn_slowpath_fmt (kernel/panic.c:445)
      debug_print_object (lib/debugobjects.c:262)
      __debug_check_no_obj_freed (lib/debugobjects.c:697)
      debug_check_no_obj_freed (lib/debugobjects.c:726)
      kmem_cache_free (mm/slub.c:2689 mm/slub.c:2717)
      kmem_cache_destroy (mm/slab_common.c:363)
      dcookie_unregister (fs/dcookies.c:302 fs/dcookies.c:343)
      event_buffer_release (arch/x86/oprofile/../../../drivers/oprofile/event_buffer.c:153)
      __fput (fs/file_table.c:217)
      ____fput (fs/file_table.c:253)
      task_work_run (kernel/task_work.c:125 (discriminator 1))
      do_notify_resume (include/linux/tracehook.h:196 arch/x86/kernel/signal.c:751)
      int_signal (arch/x86/kernel/entry_64.S:807)

Sysfs has a release mechanism.  Use that to release the kmem_cache
structure if CONFIG_SYSFS is enabled.

Only slub is changed - slab currently only supports /proc/slabinfo and
not /sys/kernel/slab/*.  We talked about adding that and someone was
working on it.

[akpm@linux-foundation.org: fix CONFIG_SYSFS=n build]
[akpm@linux-foundation.org: fix CONFIG_SYSFS=n build even more]
Signed-off-by: Christoph Lameter <cl@linux.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Greg KH <greg@kroah.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-06 13:04:59 -07:00
Johannes Weiner
623762517e revert "mm: vmscan: do not swap anon pages just because free+file is low"
This reverts commit 0bf1457f0c ("mm: vmscan: do not swap anon pages
just because free+file is low") because it introduced a regression in
mostly-anonymous workloads, where reclaim would become ineffective and
trap every allocating task in direct reclaim.

The problem is that there is a runaway feedback loop in the scan balance
between file and anon, where the balance tips heavily towards a tiny
thrashing file LRU and anonymous pages are no longer being looked at.
The commit in question removed the safe guard that would detect such
situations and respond with forced anonymous reclaim.

This commit was part of a series to fix premature swapping in loads with
relatively little cache, and while it made a small difference, the cure
is obviously worse than the disease.  Revert it.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: <stable@kernel.org>		[3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-06 13:04:59 -07:00
Johannes Weiner
139b6a6fb1 mm: filemap: update find_get_pages_tag() to deal with shadow entries
Dave Jones reports the following crash when find_get_pages_tag() runs
into an exceptional entry:

  kernel BUG at mm/filemap.c:1347!
  RIP: find_get_pages_tag+0x1cb/0x220
  Call Trace:
    find_get_pages_tag+0x36/0x220
    pagevec_lookup_tag+0x21/0x30
    filemap_fdatawait_range+0xbe/0x1e0
    filemap_fdatawait+0x27/0x30
    sync_inodes_sb+0x204/0x2a0
    sync_inodes_one_sb+0x19/0x20
    iterate_supers+0xb2/0x110
    sys_sync+0x44/0xb0
    ia32_do_call+0x13/0x13

  1343                         /*
  1344                          * This function is never used on a shmem/tmpfs
  1345                          * mapping, so a swap entry won't be found here.
  1346                          */
  1347                         BUG();

After commit 0cd6144aad ("mm + fs: prepare for non-page entries in
page cache radix trees") this comment and BUG() are out of date because
exceptional entries can now appear in all mappings - as shadows of
recently evicted pages.

However, as Hugh Dickins notes,

  "it is truly surprising for a PAGECACHE_TAG_WRITEBACK (and probably
   any other PAGECACHE_TAG_*) to appear on an exceptional entry.

   I expect it comes down to an occasional race in RCU lookup of the
   radix_tree: lacking absolute synchronization, we might sometimes
   catch an exceptional entry, with the tag which really belongs with
   the unexceptional entry which was there an instant before."

And indeed, not only is the tree walk lockless, the tags are also read
in chunks, one radix tree node at a time.  There is plenty of time for
page reclaim to swoop in and replace a page that was already looked up
as tagged with a shadow entry.

Remove the BUG() and update the comment.  While reviewing all other
lookup sites for whether they properly deal with shadow entries of
evicted pages, update all the comments and fix memcg file charge moving
to not miss shmem/tmpfs swapcache pages.

Fixes: 0cd6144aad ("mm + fs: prepare for non-page entries in page cache radix trees")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Dave Jones <davej@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-06 13:04:59 -07:00
Vlastimil Babka
49e068f0b7 mm/compaction: make isolate_freepages start at pageblock boundary
The compaction freepage scanner implementation in isolate_freepages()
starts by taking the current cc->free_pfn value as the first pfn.  In a
for loop, it scans from this first pfn to the end of the pageblock, and
then subtracts pageblock_nr_pages from the first pfn to obtain the first
pfn for the next for loop iteration.

This means that when cc->free_pfn starts at offset X rather than being
aligned on pageblock boundary, the scanner will start at offset X in all
scanned pageblock, ignoring potentially many free pages.  Currently this
can happen when

 a) zone's end pfn is not pageblock aligned, or

 b) through zone->compact_cached_free_pfn with CONFIG_HOLES_IN_ZONE
    enabled and a hole spanning the beginning of a pageblock

This patch fixes the problem by aligning the initial pfn in
isolate_freepages() to pageblock boundary.  This also permits replacing
the end-of-pageblock alignment within the for loop with a simple
pageblock_nr_pages increment.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Heesub Shin <heesub.shin@samsung.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: 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>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Dongjun Shin <d.j.shin@samsung.com>
Cc: Sunghwan Yun <sunghwan.yun@samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-06 13:04:59 -07:00
Rik van Riel
d5c9fde3da mm/page-writeback.c: fix divide by zero in pos_ratio_polynom
It is possible for "limit - setpoint + 1" to equal zero, after getting
truncated to a 32 bit variable, and resulting in a divide by zero error.

Using the fully 64 bit divide functions avoids this problem.  It also
will cause pos_ratio_polynom() to return the correct value when
(setpoint - limit) exceeds 2^32.

Also uninline pos_ratio_polynom, at Andrew's request.

Signed-off-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-06 13:04:58 -07:00
Nishanth Aravamudan
457c1b27ed hugetlb: ensure hugepage access is denied if hugepages are not supported
Currently, I am seeing the following when I `mount -t hugetlbfs /none
/dev/hugetlbfs`, and then simply do a `ls /dev/hugetlbfs`.  I think it's
related to the fact that hugetlbfs is properly not correctly setting
itself up in this state?:

  Unable to handle kernel paging request for data at address 0x00000031
  Faulting instruction address: 0xc000000000245710
  Oops: Kernel access of bad area, sig: 11 [#1]
  SMP NR_CPUS=2048 NUMA pSeries
  ....

In KVM guests on Power, in a guest not backed by hugepages, we see the
following:

  AnonHugePages:         0 kB
  HugePages_Total:       0
  HugePages_Free:        0
  HugePages_Rsvd:        0
  HugePages_Surp:        0
  Hugepagesize:         64 kB

HPAGE_SHIFT == 0 in this configuration, which indicates that hugepages
are not supported at boot-time, but this is only checked in
hugetlb_init().  Extract the check to a helper function, and use it in a
few relevant places.

This does make hugetlbfs not supported (not registered at all) in this
environment.  I believe this is fine, as there are no valid hugepages
and that won't change at runtime.

[akpm@linux-foundation.org: use pr_info(), per Mel]
[akpm@linux-foundation.org: fix build when HPAGE_SHIFT is undefined]
Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-06 13:04:58 -07:00