Pavel reported that in case if vma area get unmapped and then mapped (or
expanded) in-place, the soft dirty tracker won't be able to recognize this
situation since it works on pte level and ptes are get zapped on unmap,
loosing soft dirty bit of course.

So to resolve this situation we need to track actions on vma level, there
VM_SOFTDIRTY flag comes in.  When new vma area created (or old expanded)
we set this bit, and keep it here until application calls for clearing
soft dirty bit.

Thus when user space application track memory changes now it can detect if
vma area is renewed.
Reported-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Current early_pfn_to_nid() on arch that support memblock go over
memblock.memory one by one, so will take too many try near the end.

We can use existing memblock_search to find the node id for given pfn,
that could save some time on bigger system that have many entries
memblock.memory array.

Here are the timing differences for several machines.  In each case with
the patch less time was spent in __early_pfn_to_nid().

                        3.11-rc5        with patch      difference (%)
                        --------        ----------      --------------
UV1: 256 nodes  9TB:     411.66          402.47         -9.19 (2.23%)
UV2: 255 nodes 16TB:    1141.02         1138.12         -2.90 (0.25%)
UV2:  64 nodes  2TB:     128.15          126.53         -1.62 (1.26%)
UV2:  32 nodes  2TB:     121.87          121.07         -0.80 (0.66%)
                        Time in seconds.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: NRuss Anderson <rja@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently hugepage migration works well only for pmd-based hugepages
(mainly due to lack of testing,) so we had better not enable migration of
other levels of hugepages until we are ready for it.

Some users of hugepage migration (mbind, move_pages, and migrate_pages) do
page table walk and check pud/pmd_huge() there, so they are safe.  But the
other users (softoffline and memory hotremove) don't do this, so without
this patch they can try to migrate unexpected types of hugepages.

To prevent this, we introduce hugepage_migration_support() as an
architecture dependent check of whether hugepage are implemented on a pmd
basis or not.  And on some architecture multiple sizes of hugepages are
available, so hugepage_migration_support() also checks hugepage size.
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Until now we can't offline memory blocks which contain hugepages because a
hugepage is considered as an unmovable page.  But now with this patch
series, a hugepage has become movable, so by using hugepage migration we
can offline such memory blocks.

What's different from other users of hugepage migration is that we need to
decompose all the hugepages inside the target memory block into free buddy
pages after hugepage migration, because otherwise free hugepages remaining
in the memory block intervene the memory offlining.  For this reason we
introduce new functions dissolve_free_huge_page() and
dissolve_free_huge_pages().

Other than that, what this patch does is straightforwardly to add hugepage
migration code, that is, adding hugepage code to the functions which scan
over pfn and collect hugepages to be migrated, and adding a hugepage
allocation function to alloc_migrate_target().

As for larger hugepages (1GB for x86_64), it's not easy to do hotremove
over them because it's larger than memory block.  So we now simply leave
it to fail as it is.

[yongjun_wei@trendmicro.com.cn: remove duplicated include]
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: NAndi Kleen <ak@linux.intel.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Enable hugepage migration from migrate_pages(2), move_pages(2), and
mbind(2).
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: NHillf Danton <dhillf@gmail.com>
Acked-by: NAndi Kleen <ak@linux.intel.com>
Reviewed-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Extend do_mbind() to handle vma with VM_HUGETLB set.  We will be able to
migrate hugepage with mbind(2) after applying the enablement patch which
comes later in this series.
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: NAndi Kleen <ak@linux.intel.com>
Reviewed-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: NHillf Danton <dhillf@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently migrate_huge_page() takes a pointer to a hugepage to be migrated
as an argument, instead of taking a pointer to the list of hugepages to be
migrated.  This behavior was introduced in commit 189ebff2 ("hugetlb:
simplify migrate_huge_page()"), and was OK because until now hugepage
migration is enabled only for soft-offlining which migrates only one
hugepage in a single call.

But the situation will change in the later patches in this series which
enable other users of page migration to support hugepage migration.  They
can kick migration for both of normal pages and hugepages in a single
call, so we need to go back to original implementation which uses linked
lists to collect the hugepages to be migrated.

With this patch, soft_offline_huge_page() switches to use migrate_pages(),
and migrate_huge_page() is not used any more.  So let's remove it.
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: NAndi Kleen <ak@linux.intel.com>
Reviewed-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: NHillf Danton <dhillf@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently hugepage migration is available only for soft offlining, but
it's also useful for some other users of page migration (clearly because
users of hugepage can enjoy the benefit of mempolicy and memory hotplug.)
So this patchset tries to extend such users to support hugepage migration.

The target of this patchset is to enable hugepage migration for NUMA
related system calls (migrate_pages(2), move_pages(2), and mbind(2)), and
memory hotplug.

This patchset does not add hugepage migration for memory compaction,
because users of memory compaction mainly expect to construct thp by
arranging raw pages, and there's little or no need to compact hugepages.
CMA, another user of page migration, can have benefit from hugepage
migration, but is not enabled to support it for now (just because of lack
of testing and expertise in CMA.)

Hugepage migration of non pmd-based hugepage (for example 1GB hugepage in
x86_64, or hugepages in architectures like ia64) is not enabled for now
(again, because of lack of testing.)

As for how these are achived, I extended the API (migrate_pages()) to
handle hugepage (with patch 1 and 2) and adjusted code of each caller to
check and collect movable hugepages (with patch 3-7).  Remaining 2 patches
are kind of miscellaneous ones to avoid unexpected behavior.  Patch 8 is
about making sure that we only migrate pmd-based hugepages.  And patch 9
is about choosing appropriate zone for hugepage allocation.

My test is mainly functional one, simply kicking hugepage migration via
each entry point and confirm that migration is done correctly.  Test code
is available here:

  git://github.com/Naoya-Horiguchi/test_hugepage_migration_extension.git

And I always run libhugetlbfs test when changing hugetlbfs's code.  With
this patchset, no regression was found in the test.

This patch (of 9):

Before enabling each user of page migration to support hugepage,
this patch enables the list of pages for migration to link not only
LRU pages, but also hugepages. As a result, putback_movable_pages()
and migrate_pages() can handle both of LRU pages and hugepages.
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: NAndi Kleen <ak@linux.intel.com>
Reviewed-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: NHillf Danton <dhillf@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In struct gen_pool_chunk, end_addr means the end address of memory chunk
(inclusive), but in the implementation it is treated as address + size of
memory chunk (exclusive), so it points to the address plus one instead of
correct ending address.

The ending address of memory chunk plus one will cause overflow on the
memory chunk including the last address of memory map, e.g.  when starting
address is 0xFFF00000 and size is 0x100000 on 32bit machine, ending
address will be 0x100000000.

Use correct ending address like starting address + size - 1.

[akpm@linux-foundation.org: add comment to struct gen_pool_chunk:end_addr]
Signed-off-by: NJoonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The main idea behind this patchset is to reduce the vmstat update overhead
by avoiding interrupt enable/disable and the use of per cpu atomics.

This patch (of 3):

It is better to have a separate folding function because
refresh_cpu_vm_stats() also does other things like expire pages in the
page allocator caches.

If we have a separate function then refresh_cpu_vm_stats() is only called
from the local cpu which allows additional optimizations.

The folding function is only called when a cpu is being downed and
therefore no other processor will be accessing the counters.  Also
simplifies synchronization.

[akpm@linux-foundation.org: fix UP build]
Signed-off-by: NChristoph Lameter <cl@linux.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
CC: Tejun Heo <tj@kernel.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

PageSwapCache() is always false when !CONFIG_SWAP, so compiler
properly discard related code. Therefore, we don't need #ifdef explicitly.
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Each zone that holds userspace pages of one workload must be aged at a
speed proportional to the zone size.  Otherwise, the time an individual
page gets to stay in memory depends on the zone it happened to be
allocated in.  Asymmetry in the zone aging creates rather unpredictable
aging behavior and results in the wrong pages being reclaimed, activated
etc.

But exactly this happens right now because of the way the page allocator
and kswapd interact.  The page allocator uses per-node lists of all zones
in the system, ordered by preference, when allocating a new page.  When
the first iteration does not yield any results, kswapd is woken up and the
allocator retries.  Due to the way kswapd reclaims zones below the high
watermark while a zone can be allocated from when it is above the low
watermark, the allocator may keep kswapd running while kswapd reclaim
ensures that the page allocator can keep allocating from the first zone in
the zonelist for extended periods of time.  Meanwhile the other zones
rarely see new allocations and thus get aged much slower in comparison.

The result is that the occasional page placed in lower zones gets
relatively more time in memory, even gets promoted to the active list
after its peers have long been evicted.  Meanwhile, the bulk of the
working set may be thrashing on the preferred zone even though there may
be significant amounts of memory available in the lower zones.

Even the most basic test -- repeatedly reading a file slightly bigger than
memory -- shows how broken the zone aging is.  In this scenario, no single
page should be able stay in memory long enough to get referenced twice and
activated, but activation happens in spades:

  $ grep active_file /proc/zoneinfo
      nr_inactive_file 0
      nr_active_file 0
      nr_inactive_file 0
      nr_active_file 8
      nr_inactive_file 1582
      nr_active_file 11994
  $ cat data data data data >/dev/null
  $ grep active_file /proc/zoneinfo
      nr_inactive_file 0
      nr_active_file 70
      nr_inactive_file 258753
      nr_active_file 443214
      nr_inactive_file 149793
      nr_active_file 12021

Fix this with a very simple round robin allocator.  Each zone is allowed a
batch of allocations that is proportional to the zone's size, after which
it is treated as full.  The batch counters are reset when all zones have
been tried and the allocator enters the slowpath and kicks off kswapd
reclaim.  Allocation and reclaim is now fairly spread out to all
available/allowable zones:

  $ grep active_file /proc/zoneinfo
      nr_inactive_file 0
      nr_active_file 0
      nr_inactive_file 174
      nr_active_file 4865
      nr_inactive_file 53
      nr_active_file 860
  $ cat data data data data >/dev/null
  $ grep active_file /proc/zoneinfo
      nr_inactive_file 0
      nr_active_file 0
      nr_inactive_file 666622
      nr_active_file 4988
      nr_inactive_file 190969
      nr_active_file 937

When zone_reclaim_mode is enabled, allocations will now spread out to all
zones on the local node, not just the first preferred zone (which on a 4G
node might be a tiny Normal zone).
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMel Gorman <mgorman@suse.de>
Reviewed-by: NRik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Paul Bolle <paul.bollee@gmail.com>
Cc: Zlatko Calusic <zcalusic@bitsync.net>
Tested-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

swap cluster allocation is to get better request merge to improve
performance.  But the cluster is shared globally, if multiple tasks are
doing swap, this will cause interleave disk access.  While multiple tasks
swap is quite common, for example, each numa node has a kswapd thread
doing swap and multiple threads/processes doing direct page reclaim.

ioscheduler can't help too much here, because tasks don't send swapout IO
down to block layer in the meantime.  Block layer does merge some IOs, but
a lot not, depending on how many tasks are doing swapout concurrently.  In
practice, I've seen a lot of small size IO in swapout workloads.

We makes the cluster allocation per-cpu here.  The interleave disk access
issue goes away.  All tasks swapout to their own cluster, so swapout will
become sequential, which can be easily merged to big size IO.  If one CPU
can't get its per-cpu cluster (for example, there is no free cluster
anymore in the swap), it will fallback to scan swap_map.  The CPU can
still continue swap.  We don't need recycle free swap entries of other
CPUs.

In my test (swap to a 2-disk raid0 partition), this improves around 10%
swapout throughput, and request size is increased significantly.

How does this impact swap readahead is uncertain though.  On one side,
page reclaim always isolates and swaps several adjancent pages, this will
make page reclaim write the pages sequentially and benefit readahead.  On
the other side, several CPU write pages interleave means the pages don't
live _sequentially_ but relatively _near_.  In the per-cpu allocation
case, if adjancent pages are written by different cpus, they will live
relatively _far_.  So how this impacts swap readahead depends on how many
pages page reclaim isolates and swaps one time.  If the number is big,
this patch will benefit swap readahead.  Of course, this is about
sequential access pattern.  The patch has no impact for random access
pattern, because the new cluster allocation algorithm is just for SSD.

Alternative solution is organizing swap layout to be per-mm instead of
this per-cpu approach.  In the per-mm layout, we allocate a disk range for
each mm, so pages of one mm live in swap disk adjacently.  per-mm layout
has potential issues of lock contention if multiple reclaimers are swap
pages from one mm.  For a sequential workload, per-mm layout is better to
implement swap readahead, because pages from the mm are adjacent in disk.
But per-cpu layout isn't very bad in this workload, as page reclaim always
isolates and swaps several pages one time, such pages will still live in
disk sequentially and readahead can utilize this.  For a random workload,
per-mm layout isn't beneficial of request merge, because it's quite
possible pages from different mm are swapout in the meantime and IO can't
be merged in per-mm layout.  while with per-cpu layout we can merge
requests from any mm.  Considering random workload is more popular in
workloads with swap (and per-cpu approach isn't too bad for sequential
workload too), I'm choosing per-cpu layout.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NShaohua Li <shli@fusionio.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rafael Aquini <aquini@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

swap can do cluster discard for SSD, which is good, but there are some
problems here:

1. swap do the discard just before page reclaim gets a swap entry and
   writes the disk sectors.  This is useless for high end SSD, because an
   overwrite to a sector implies a discard to original sector too.  A
   discard + overwrite == overwrite.

2. the purpose of doing discard is to improve SSD firmware garbage
   collection.  Idealy we should send discard as early as possible, so
   firmware can do something smart.  Sending discard just after swap entry
   is freed is considered early compared to sending discard before write.
   Of course, if workload is already bound to gc speed, sending discard
   earlier or later doesn't make

3. block discard is a sync API, which will delay scan_swap_map()
   significantly.

4. Write and discard command can be executed parallel in PCIe SSD.
   Making swap discard async can make execution more efficiently.

This patch makes swap discard async and moves discard to where swap entry
is freed.  Discard and write have no dependence now, so above issues can
be avoided.  Idealy we should do discard for any freed sectors, but some
SSD discard is very slow.  This patch still does discard for a whole
cluster.

My test does a several round of 'mmap, write, unmap', which will trigger a
lot of swap discard.  In a fusionio card, with this patch, the test
runtime is reduced to 18% of the time without it, so around 5.5x faster.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NShaohua Li <shli@fusionio.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rafael Aquini <aquini@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I'm using a fast SSD to do swap.  scan_swap_map() sometimes uses up to
20~30% CPU time (when cluster is hard to find, the CPU time can be up to
80%), which becomes a bottleneck.  scan_swap_map() scans a byte array to
search a 256 page cluster, which is very slow.

Here I introduced a simple algorithm to search cluster.  Since we only
care about 256 pages cluster, we can just use a counter to track if a
cluster is free.  Every 256 pages use one int to store the counter.  If
the counter of a cluster is 0, the cluster is free.  All free clusters
will be added to a list, so searching cluster is very efficient.  With
this, scap_swap_map() overhead disappears.

This might help low end SD card swap too.  Because if the cluster is
aligned, SD firmware can do flash erase more efficiently.

We only enable the algorithm for SSD.  Hard disk swap isn't fast enough
and has downside with the algorithm which might introduce regression (see
below).

The patch slightly changes which cluster is choosen.  It always adds free
cluster to list tail.  This can help wear leveling for low end SSD too.
And if no cluster found, the scan_swap_map() will do search from the end
of last cluster.  So if no cluster found, the scan_swap_map() will do
search from the end of last free cluster, which is random.  For SSD, this
isn't a problem at all.

Another downside is the cluster must be aligned to 256 pages, which will
reduce the chance to find a cluster.  I would expect this isn't a big
problem for SSD because of the non-seek penality.  (And this is the reason
I only enable the algorithm for SSD).
Signed-off-by: NShaohua Li <shli@fusionio.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rafael Aquini <aquini@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The previous patch doing vmstats for TLB flushes ("mm: vmstats: tlb flush
counters") effectively missed UP since arch/x86/mm/tlb.c is only compiled
for SMP.

UP systems do not do remote TLB flushes, so compile those counters out on
UP.

arch/x86/kernel/cpu/mtrr/generic.c calls __flush_tlb() directly.  This is
probably an optimization since both the mtrr code and __flush_tlb() write
cr4.  It would probably be safe to make that a flush_tlb_all() (and then
get these statistics), but the mtrr code is ancient and I'm hesitant to
touch it other than to just stick in the counters.

[akpm@linux-foundation.org: tweak comments]
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I was investigating some TLB flush scaling issues and realized that we do
not have any good methods for figuring out how many TLB flushes we are
doing.

It would be nice to be able to do these in generic code, but the
arch-independent calls don't explicitly specify whether we actually need
to do remote flushes or not.  In the end, we really need to know if we
actually _did_ global vs.  local invalidations, so that leaves us with few
options other than to muck with the counters from arch-specific code.
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Simple cleanup.  Every user of vma_set_policy() does the same work, this
looks a bit annoying imho.  And the new trivial helper which does
mpol_dup() + vma_set_policy() to simplify the callers.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Read block device partition table from command line.  The partition used
for fixed block device (eMMC) embedded device.  It is no MBR, save
storage space.  Bootloader can be easily accessed by absolute address of
data on the block device.  Users can easily change the partition.

This code reference MTD partition, source "drivers/mtd/cmdlinepart.c"
About the partition verbose reference
"Documentation/block/cmdline-partition.txt"

[akpm@linux-foundation.org: fix printk text]
[yongjun_wei@trendmicro.com.cn: fix error return code in parse_parts()]
Signed-off-by: NCai Zhiyong <caizhiyong@huawei.com>
Cc: Karel Zak <kzak@redhat.com>
Cc: "Wanglin (Albert)" <albert.wanglin@huawei.com>
Cc: Marius Groeger <mag@sysgo.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

task_struct->pid/tgid should go away.

1. Change same_thread_group() to use task->signal for comparison.

2. Change has_group_leader_pid(task) to compare task_pid(task) with
   signal->leader_pid.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Sergey Dyasly <dserrg@gmail.com>
Reviewed-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Revert commit c846ef7d ("include/linux/smp.h:on_each_cpu(): switch
back to a macro").  It turns out that the problematic linux/irqflags.h
include was fixed within ia64 and mn10300.

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: David Daney <david.daney@cavium.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dma_sync_wait and dma_find_channel are declared regardless of whether
CONFIG_DMA_ENGINE is enabled, but calling the function without
CONFIG_DMA_ENGINE enabled results "undefined reference" errors.

To get around this, declare dma_sync_wait and dma_find_channel as inline
functions if CONFIG_DMA_ENGINE is undefined.
Signed-off-by: NJon Mason <jon.mason@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and move the extern from linux/namei.h to fs/internal.h,
along with that of vfs_path_lookup().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This is me being a bit OCD after all the dentry optimization work this
merge window: profiles end up showing 'dput()' as a rather expensive
operation, and there were two unrelated bad reasons for that.

The first reason was reading d_lockref.count for debugging purposes,
which touches the lockref cacheline (for reads) before really need to.
More importantly, the debugging test in question is _wrong_, and has
hidden bugs.  It's true that we can only sleep when the count goes down
to zero, but the test as-is hides the much more subtle bug that happens
if we race with somebody else deleting the file.

Anyway we _will_ touch that cacheline, but let's do it for a write and
in the right routine (ie in "lockref_put_or_lock()") which annotates the
costs better.  So remove the misleading debug code.

The other was an unnecessary access to the cacheline that contains the
d_lru list, just to check whether we already were on the LRU list or
not.  This is exactly what we have d_flags for, so that we can avoid
touching extra cache lines for the common case.  So just add another bit
for "is this dentry on the LRU".

Finally, mark the tests properly likely/unlikely, so that the common
fast-paths are dense in the instruction stream.

This makes the profiles look much saner.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kernel/cgroup.c is the only place in the tree that relies on eventfd.h
pulling file.h; move that include there.  Switch from eventfd_fget()/fput()
to fdget()/fdput(), while we are at it - eventfd_ctx_fileget() will fail
on non-eventfd descriptors just fine, no need to do that check twice...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The only actual current lockref user (dcache) uses zero reference counts
even for perfectly live dentries, because it's a cache: there may not be
any users, but that doesn't mean that we want to throw away the dentry.

At the same time, the dentry cache does have a notion of a truly "dead"
dentry that we must not even increment the reference count of, because
we have pruned it and it is not valid.

Currently that distinction is not visible in the lockref itself, and the
dentry cache validation uses "lockref_get_or_lock()" to either get a new
reference to a dentry that already had existing references (and thus
cannot be dead), or get the dentry lock so that we can then verify the
dentry and increment the reference count under the lock if that
verification was successful.

That's all somewhat complicated.

This adds the concept of being "dead" to the lockref itself, by simply
using a count that is negative.  This allows a usage scenario where we
can increment the refcount of a dentry without having to validate it,
and pushing the special "we killed it" case into the lockref code.

The dentry code itself doesn't actually use this yet, and it's probably
too late in the merge window to do that code (the dentry_kill() code
with its "should I decrement the count" logic really is pretty complex
code), but let's introduce the concept at the lockref level now.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commits 61e00655, 73f8645d and 8e22ecb6:
  "Input: introduce BTN/ABS bits for drums and guitars"
  "HID: wiimote: add support for Guitar-Hero drums"
  "HID: wiimote: add support for Guitar-Hero guitars"

The extra new ABS_xx values resulted in ABS_MAX no longer being a
power-of-two, which broke the comparison logic.  It also caused the
ioctl numbers to overflow into the next byte, causing problems for that.

We'll try again for 3.13.
Reported-by: NMarkus Trippelsdorf <markus@trippelsdorf.de>
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Acked-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch reinstates commits
	67822649
	39761214
	0b95a7f8
	31d93962
	2d31e518

Now that module softdeps are in the kernel we can use that to resolve
the boot issue which cause the revert.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Commit 4edaa308 "NFS: Use "krb5i" to establish NFSv4 state whenever possible"
uses the nfs_client cl_rpcclient for all state management operations, and
will use krb5i or auth_sys with no regard to the mount command authflavor
choice.

The MDS, as any NFSv4.1 mount point, uses the nfs_server rpc client for all
non-state management operations with a different nfs_server for each fsid
encountered traversing the mount point, each with a potentially different
auth flavor.

pNFS data servers are not mounted in the normal sense as there is no associated
nfs_server structure. Data servers can also export multiple fsids, each with
a potentially different auth flavor.

Data servers need to use the same authflavor as the MDS server rpc client for
non-state management operations. Populate a list of rpc clients with the MDS
server rpc client auth flavor for the DS to use.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Provide a kernel-doc comment documentation for the BQL helpers:
- netdev_sent_queue
- netdev_completed_queue
- netdev_reset_queue

Similarly to how it is done for the other functions, the documentation
only covers the function operating on struct net_device and not struct
netdev_queue.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 3af9d15c, which
causes a build failure:

drivers/mfd/asic3.c:724:2: error: unknown field 'set_pwr' specified in initializer

Currently the fscache code expect the netfs to call fscache_readpages_or_alloc
inside the aops readpages callback.  It marks all the pages in the list
provided by readahead with PG_private_2.  In the cases that the netfs fails to
read all the pages (which is legal) it ends up returning to the readahead and
triggering a BUG.  This happens because the page list still contains marked
pages.

This patch implements a simple fscache_readpages_cancel function that the netfs
should call before returning from readpages.  It will revoke the pages from the
underlying cache backend and unmark them.

The problem was originally worked out in the Ceph devel tree, but it also
occurs in CIFS.  It appears that NFS, AFS and 9P are okay as read_cache_pages()
will clean up the unprocessed pages in the case of an error.

This can be used to address the following oops:

[12410647.597278] BUG: Bad page state in process petabucket  pfn:3d504e
[12410647.597292] page:ffffea000f541380 count:0 mapcount:0 mapping:
	(null) index:0x0
[12410647.597298] page flags: 0x200000000001000(private_2)

...

[12410647.597334] Call Trace:
[12410647.597345]  [<ffffffff815523f2>] dump_stack+0x19/0x1b
[12410647.597356]  [<ffffffff8111def7>] bad_page+0xc7/0x120
[12410647.597359]  [<ffffffff8111e49e>] free_pages_prepare+0x10e/0x120
[12410647.597361]  [<ffffffff8111fc80>] free_hot_cold_page+0x40/0x170
[12410647.597363]  [<ffffffff81123507>] __put_single_page+0x27/0x30
[12410647.597365]  [<ffffffff81123df5>] put_page+0x25/0x40
[12410647.597376]  [<ffffffffa02bdcf9>] ceph_readpages+0x2e9/0x6e0 [ceph]
[12410647.597379]  [<ffffffff81122a8f>] __do_page_cache_readahead+0x1af/0x260
[12410647.597382]  [<ffffffff81122ea1>] ra_submit+0x21/0x30
[12410647.597384]  [<ffffffff81118f64>] filemap_fault+0x254/0x490
[12410647.597387]  [<ffffffff8113a74f>] __do_fault+0x6f/0x4e0
[12410647.597391]  [<ffffffff810125bd>] ? __switch_to+0x16d/0x4a0
[12410647.597395]  [<ffffffff810865ba>] ? finish_task_switch+0x5a/0xc0
[12410647.597398]  [<ffffffff8113d856>] handle_pte_fault+0xf6/0x930
[12410647.597401]  [<ffffffff81008c33>] ? pte_mfn_to_pfn+0x93/0x110
[12410647.597403]  [<ffffffff81008cce>] ? xen_pmd_val+0xe/0x10
[12410647.597405]  [<ffffffff81005469>] ? __raw_callee_save_xen_pmd_val+0x11/0x1e
[12410647.597407]  [<ffffffff8113f361>] handle_mm_fault+0x251/0x370
[12410647.597411]  [<ffffffff812b0ac4>] ? call_rwsem_down_read_failed+0x14/0x30
[12410647.597414]  [<ffffffff8155bffa>] __do_page_fault+0x1aa/0x550
[12410647.597418]  [<ffffffff8108011d>] ? up_write+0x1d/0x20
[12410647.597422]  [<ffffffff8113141c>] ? vm_mmap_pgoff+0xbc/0xe0
[12410647.597425]  [<ffffffff81143bb8>] ? SyS_mmap_pgoff+0xd8/0x240
[12410647.597427]  [<ffffffff8155c3ae>] do_page_fault+0xe/0x10
[12410647.597431]  [<ffffffff81558818>] page_fault+0x28/0x30
Signed-off-by: NMilosz Tanski <milosz@adfin.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Extend the fscache netfs API so that the netfs can ask as to whether a cache
object is up to date with respect to its corresponding netfs object:

	int fscache_check_consistency(struct fscache_cookie *cookie)

This will call back to the netfs to check whether the auxiliary data associated
with a cookie is correct.  It returns 0 if it is and -ESTALE if it isn't; it
may also return -ENOMEM and -ERESTARTSYS.

The backends now have to implement a mandatory operation pointer:

	int (*check_consistency)(struct fscache_object *object)

that corresponds to the above API call.  FS-Cache takes care of pinning the
object and the cookie in memory and managing this call with respect to the
object state.

Original-author: Hongyi Jia <jiayisuse@gmail.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: Hongyi Jia <jiayisuse@gmail.com>
cc: Milosz Tanski <milosz@adfin.com>

Support the collection of I/O statistics on user-defined regions of
a DM device.  If no regions are defined no statistics are collected so
there isn't any performance impact.  Only bio-based DM devices are
currently supported.

Each user-defined region specifies a starting sector, length and step.
Individual statistics will be collected for each step-sized area within
the range specified.

The I/O statistics counters for each step-sized area of a region are
in the same format as /sys/block/*/stat or /proc/diskstats but extra
counters (12 and 13) are provided: total time spent reading and
writing in milliseconds.  All these counters may be accessed by sending
the @stats_print message to the appropriate DM device via dmsetup.

The creation of DM statistics will allocate memory via kmalloc or
fallback to using vmalloc space.  At most, 1/4 of the overall system
memory may be allocated by DM statistics.  The admin can see how much
memory is used by reading
/sys/module/dm_mod/parameters/stats_current_allocated_bytes

See Documentation/device-mapper/statistics.txt for more details.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We check submounts before doing d_drop() on a non-empty directory dentry in
NFS (have_submounts()), but we do not exclude a racing mount.

 Process A: have_submounts() -> returns false
 Process B: mount() -> success
 Process A: d_drop()

This patch prepares the ground for the fix by doing the following
operations all under the same rename lock:

  have_submounts()
  shrink_dcache_parent()
  d_drop()

This is actually an optimization since have_submounts() and
shrink_dcache_parent() both traverse the same dentry tree separately.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
CC: David Howells <dhowells@redhat.com>
CC: Steven Whitehouse <swhiteho@redhat.com>
CC: Trond Myklebust <Trond.Myklebust@netapp.com>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch adds two more ndo ops: ndo_add_rx_vxlan_port() and
ndo_del_rx_vxlan_port().

Drivers can get notifications through the above functions about changes
of the UDP listening port of VXLAN. Also, when physical ports come up,
now they can call vxlan_get_rx_port() in order to obtain the port number(s)
of the existing VXLAN interface in case they already up before them.

This information about the listening UDP port would be used for VXLAN
related offloads.

A big thank you to John Fastabend (john.r.fastabend@intel.com) for his
input and his suggestions on this patch set.

CC: John Fastabend <john.r.fastabend@intel.com>
CC: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NJoseph Gasparakis <joseph.gasparakis@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

WRITE and COMMIT can use the machine credential.

If WRITE is supported and COMMIT is not, make all (mach cred) writes FILE_SYNC4.
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

TEST_STATEID and FREE_STATEID can use the machine credential.
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>