Create a kernel/rcutree_plugin.h file that contains definitions
for preemptable RCU (or, under the #else branch of the #ifdef,
empty definitions for the classic non-preemptable semantics).
These definitions fit into plugins defined in kernel/rcutree.c
for this purpose.

This variant of preemptable RCU uses a new algorithm whose
read-side expense is roughly that of classic hierarchical RCU
under CONFIG_PREEMPT. This new algorithm's update-side expense
is similar to that of classic hierarchical RCU, and, in absence
of read-side preemption or blocking, is exactly that of classic
hierarchical RCU.  Perhaps more important, this new algorithm
has a much simpler implementation, saving well over 1,000 lines
of code compared to mainline's implementation of preemptable
RCU, which will hopefully be retired in favor of this new
algorithm.

The simplifications are obtained by maintaining per-task
nesting state for running tasks, and using a simple
lock-protected algorithm to handle accounting when tasks block
within RCU read-side critical sections, making use of lessons
learned while creating numerous user-level RCU implementations
over the past 18 months.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <12509746134003-git-send-email->
Signed-off-by: NIngo Molnar <mingo@elte.hu>

All calls from outside RCU are of the form:

	if (rcu_pending(cpu))
		rcu_check_callbacks(cpu, user);

This is silly, instead we put a call to rcu_pending() in
rcu_check_callbacks(), and then make the outside calls be to
rcu_check_callbacks().  This cuts down on the code a bit and
also gives the compiler a better chance of optimizing.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <125097461311-git-send-email->
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <12509746132349-git-send-email->
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Make RCU-sched, RCU-bh, and RCU-preempt be underlying
implementations, with "RCU" defined in terms of one of the
three.  Update the outdated rcu_qsctr_inc() names, as these
functions no longer increment anything.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <12509746132696-git-send-email->
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Some information hiding that makes it easier to merge
preemptability into rcutree without descending into #include
hell.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <1250974613373-git-send-email->
Signed-off-by: NIngo Molnar <mingo@elte.hu>

A couple of references to CONFIG_CLASSIC_RCU have survived.
Although these are harmless, it is past time for them to go.
The one in hardirq.h is strictly a readability problem.

The two in pagemap.h appear to disable a !SMP performance
optimization (which this patch re-enables).

This does raise the issue as to whether pagemap.h should really
be referring to the CPU implementation.  Long term, I intend to
make the RCU implementation driven by CONFIG_PREEMPT, at which
point these should change from defined(CONFIG_TREE_RCU) to
!defined(CONFIG_PREEMPT). In the meantime, is there something
else that could be done in pagemap.h?
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <20090822050851.GA8414@linux.vnet.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch introduces a new cpu_notifier() API that is similar
to hotcpu_notifier(), but which also notifies of CPUs coming
online during boot in the !HOTPLUG_CPU case.
Reported-by: NIngo Molnar <mingo@elte.hu>
Reported-by: NHugh Dickins <hugh.dickins@tiscali.co.uk>
Tested-by: NHugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: josht@linux.vnet.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: benh@kernel.crashing.org
LKML-Reference: <12503552312611-git-send-email->
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Replace PERF_SAMPLE_GROUP with PERF_SAMPLE_READ and introduce
PERF_FORMAT_GROUP to deal with group reads in a more generic
way.

This allows you to get group reads out of read() as well.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey J Ashford <cjashfor@us.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: stephane eranian <eranian@googlemail.com>
LKML-Reference: <20090813103655.117411814@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Provide weak aliases for hw_perf_counter_setup_online(). This is
used by the BTS patches (for v2.6.32), but it interacts with
fixes so propagate this upstream. (it has no effect as of yet)

Also export perf_counter_output() to architecture code.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

We can't call nfs_readdata_release()/nfs_writedata_release() without
first initialising and referencing args.context. Doing so inside
nfs_direct_read_schedule_segment()/nfs_direct_write_schedule_segment()
causes an Oops.

We should rather be calling nfs_readdata_free()/nfs_writedata_free() in
those cases.

Looking at the O_DIRECT code, the "struct nfs_direct_req" is already
referencing the nfs_open_context for us. Since the readdata and writedata
structures carry a reference to that, we can simplify things by getting rid
of the extra nfs_open_context references, so that we can replace all
instances of nfs_readdata_release()/nfs_writedata_release().
Reported-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Give waitqueue spinlocks their own lockdep classes when they
are initialised from init_waitqueue_head().  This means that
struct wait_queue::func functions can operate other waitqueues.

This is used by CacheFiles to catch the page from a backing fs
being unlocked and to wake up another thread to take a copy of
it.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NTakashi Iwai <tiwai@suse.de>
Cc: linux-cachefs@redhat.com
Cc: torvalds@osdl.org
Cc: akpm@linux-foundation.org
LKML-Reference: <20090810113305.17284.81508.stgit@warthog.procyon.org.uk>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

PERF_SAMPLE_* output switches should unconditionally output the
correct format, as they are the only way to unambiguously parse
the PERF_EVENT_SAMPLE data.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1249896447.17467.74.camel@twins>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Based on Peter's comments, make tracepoint sampling generic
just like all the other sampling bits are. This is a rename
with no code changes:

- PERF_SAMPLE_TP_RECORD to PERF_SAMPLE_RAW
- struct perf_tracepoint_record to perf_raw_record

We want the system in place that transport tracepoints raw
samples events into the perf ring buffer to be generalized and
usable by any type of counter.

Reported-by; Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1249698400-5441-4-git-send-email-fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch implements the kernel side support for ftrace event
record sampling.

A new counter sampling attribute is added:

   PERF_SAMPLE_TP_RECORD

which requests ftrace events record sampling. In this case
if a PERF_TYPE_TRACEPOINT counter is active and a tracepoint
fires, we emit the tracepoint binary record to the
perfcounter event buffer, as a sample.

Result, after setting PERF_SAMPLE_TP_RECORD attribute from perf
record:

 perf record -f -F 1 -a -e workqueue:workqueue_execution
 perf report -D

 0x21e18 [0x48]: event: 9
 .
 . ... raw event: size 72 bytes
 .  0000:  09 00 00 00 01 00 48 00 d0 c7 00 81 ff ff ff ff  ......H........
 .  0010:  0a 00 00 00 0a 00 00 00 21 00 00 00 00 00 00 00  ........!......
 .  0020:  2b 00 01 02 0a 00 00 00 0a 00 00 00 65 76 65 6e  +...........eve
 .  0030:  74 73 2f 31 00 00 00 00 00 00 00 00 0a 00 00 00  ts/1...........
 .  0040:  e0 b1 31 81 ff ff ff ff                          .......
.
0x21e18 [0x48]: PERF_EVENT_SAMPLE (IP, 1): 10: 0xffffffff8100c7d0 period: 33

The raw ftrace binary record starts at offset 0020.

Translation:

 struct trace_entry {
	type		= 0x2b = 43;
	flags		= 1;
	preempt_count	= 2;
	pid		= 0xa = 10;
	tgid		= 0xa = 10;
 }

 thread_comm = "events/1"
 thread_pid  = 0xa = 10;
 func	    = 0xffffffff8131b1e0 = flush_to_ldisc()

What will come next?

 - Userspace support ('perf trace'), 'flight data recorder' mode
   for perf trace, etc.

 - The unconditional copy from the profiling callback brings
   some costs however if someone wants no such sampling to
   occur, and needs to be fixed in the future. For that we need
   to have an instant access to the perf counter attribute.
   This is a matter of a flag to add in the struct ftrace_event.

 - Take care of the events recursivity! Don't ever try to record
   a lock event for example, it seems some locking is used in
   the profiling fast path and lead to a tracing recursivity.
   That will be fixed using raw spinlock or recursivity
   protection.

 - [...]

 - Profit! :-)
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix and improve comments in decompress/generic.h that describe the
decompressor API.  Also remove an unused definition, and rename INBUF_LEN
in lib/decompress_inflate.c to conform to bzip2/lzma naming.
Signed-off-by: NPhillip Lougher <phillip@lougher.demon.co.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

At first, init_task's mems_allowed is initialized as this.
 init_task->mems_allowed == node_state[N_POSSIBLE]

And cpuset's top_cpuset mask is initialized as this
 top_cpuset->mems_allowed = node_state[N_HIGH_MEMORY]

Before 2.6.29:
policy's mems_allowed is initialized as this.

  1. update tasks->mems_allowed by its cpuset->mems_allowed.
  2. policy->mems_allowed = nodes_and(tasks->mems_allowed, user's mask)

Updating task's mems_allowed in reference to top_cpuset's one.
cpuset's mems_allowed is aware of N_HIGH_MEMORY, always.

In 2.6.30: After commit 58568d2a
("cpuset,mm: update tasks' mems_allowed in time"), policy's mems_allowed
is initialized as this.

  1. policy->mems_allowd = nodes_and(task->mems_allowed, user's mask)

Here, if task is in top_cpuset, task->mems_allowed is not updated from
init's one.  Assume user excutes command as #numactrl --interleave=all
,....

  policy->mems_allowd = nodes_and(N_POSSIBLE, ALL_SET_MASK)

Then, policy's mems_allowd can includes a possible node, which has no pgdat.

MPOL's INTERLEAVE just scans nodemask of task->mems_allowd and access this
directly.

  NODE_DATA(nid)->zonelist even if NODE_DATA(nid)==NULL

Then, what's we need is making policy->mems_allowed be aware of
N_HIGH_MEMORY.  This patch does that.  But to do so, extra nodemask will
be on statck.  Because I know cpumask has a new interface of
CPUMASK_ALLOC(), I added it to node.

This patch stands on old behavior.  But I feel this fix itself is just a
Band-Aid.  But to do fundametal fix, we have to take care of memory
hotplug and it takes time.  (task->mems_allowd should be N_HIGH_MEMORY, I
think.)

mpol_set_nodemask() should be aware of N_HIGH_MEMORY and policy's nodemask
should be includes only online nodes.

In old behavior, this is guaranteed by frequent reference to cpuset's
code.  Now, most of them are removed and mempolicy has to check it by
itself.

To do check, a few nodemask_t will be used for calculating nodemask.  But,
size of nodemask_t can be big and it's not good to allocate them on stack.

Now, cpumask_t has CPUMASK_ALLOC/FREE an easy code for get scratch area.
NODEMASK_ALLOC/FREE shoudl be there.

[akpm@linux-foundation.org: cleanups & tweaks]
Tested-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Paul Menage <menage@google.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When we want to tear down an inode that lost the add to the cache race
in XFS we must not call into ->destroy_inode because that would delete
the inode that won the race from the inode cache radix tree.

This patch provides the __destroy_inode helper needed to fix this,
the actual fix will be in th next patch.  As XFS was the only reason
destroy_inode was exported we shift the export to the new __destroy_inode.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>

Currently inode_init_always calls into ->destroy_inode if the additional
initialization fails.  That's not only counter-intuitive because
inode_init_always did not allocate the inode structure, but in case of
XFS it's actively harmful as ->destroy_inode might delete the inode from
a radix-tree that has never been added.  This in turn might end up
deleting the inode for the same inum that has been instanciated by
another process and cause lots of cause subtile problems.

Also in the case of re-initializing a reclaimable inode in XFS it would
free an inode we still want to keep alive.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>

Remove assumption on the shift and size of rows/columns form
matrix_keypad driver.
Signed-off-by: NEric Miao <eric.y.miao@gmail.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

Not all tracepoints are created equal, in specific the ftrace
tracepoints are created with TRACE_EVENT_FORMAT() which does
not generate the needed bits to tie them into perf counters.

For those events, don't create the 'id' file and fail
->profile_enable when their ID is specified through other
means.
Reported-by: NChris Mason <chris.mason@oracle.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1249497664.5890.4.camel@laptop>
[ v2: fix build error in the !CONFIG_EVENT_PROFILE case ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kvm_notify_acked_irq does not check irq type, so that it sometimes
interprets msi vector as irq.  As a result, ack notifiers are not
called, which typially hangs the guest.  The fix is to track and
check irq type.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This is pure preparation of changing the ldisc reference counting to be
a true refcount that defines the lifetime of the ldisc.  But this is a
purely syntactic change for now to make the next steps easier.

This patch should make no semantic changes at all. But I wanted to make
the ldisc refcount be an atomic (I will be touching it without locks
soon enough), and I wanted to rename it so that there isn't quite as
much confusion between 'ldo->refcount' (ldisk operations refcount) and
'ld->refcount' (ldisc refcount itself) in the same file.

So it's now an atomic 'ld->users' count. It still starts at zero,
despite having a reference from 'tty->ldisc', but that will change once
we turn it into a _real_ refcount.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Tested-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Tested-by: NSergey Senozhatsky <sergey.senozhatsky@mail.by>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The patch fixes a bug when converting dev to mtd_info by using the
drvdata of the dev, the previous code used
container_of(dev, struct mtd_info, dev), but won't work for the mtdXro
devices as they created without being contained inside mtd_info structure.
Signed-off-by: NSaeed Bishara <saeed@marvell.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

When declaring static MTD partitions in board specific code, only
including <include/linux/mtd/partitions.h> should suffice without
gcc nagging us with:

In file included from arch/arm/mach-kirkwood/sheevaplug-setup.c:14:
include/linux/mtd/partitions.h:50: warning: 'struct mtd_info' declared inside parameter list
include/linux/mtd/partitions.h:50: warning: its scope is only this definition or declaration, which is probably not what you want
include/linux/mtd/partitions.h:51: warning: 'struct mtd_info' declared inside parameter list
include/linux/mtd/partitions.h:61: warning: 'struct mtd_info' declared inside parameter list
include/linux/mtd/partitions.h:67: warning: 'struct mtd_info' declared inside parameter list
Signed-off-by: NNicolas Pitre <nico@marvell.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

In order to be able to distinguish between no samples due to
inactivity and no samples due to task ended, Arjan asked for
PERF_EVENT_EXIT events. This is useful to the boot delay
instrumentation (bootchart) app.

This patch changes the PERF_EVENT_FORK to be emitted on every
clone, and adds PERF_EVENT_EXIT to be emitted on task exit,
after the task's counters have been closed.

This task tracing is controlled through: attr.comm || attr.mmap
and through the new attr.task field.
Suggested-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
[ cleaned up perf_counter.h a bit ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Introduce blk_limits_io_min() and make blk_queue_io_min() call it.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

To fix the common case where ->enable() does not set up
mult, make sure mult_orig is saved in mult on disable.

Also add comments to explain why we do this.
Signed-off-by: NMagnus Damm <damm@igel.co.jp>
Cc: johnstul@us.ibm.com
Cc: lethal@linux-sh.org
Cc: akpm@linux-foundation.org
LKML-Reference: <20090618152432.10136.9932.sendpatchset@rx1.opensource.se>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

the code allready uses flush_kernel_dcache_page(). This patch updates the
driver to the recent sg API changes which require that either SG_MITER_TO_SG
or SG_MITER_FROM_SG is set. SG_MITER_TO_SG calls flush_kernel_dcache_page()
in sg_mitter_stop()
Signed-off-by: NSebastian Andrzej Siewior <sebastian@breakpoint.cc>
Acked-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NPierre Ossman <pierre@ossman.eu>

sg_miter_start() is currently unaware of the direction of the copy
process (to or from the scatter list). It is important to know the
direction because the page has to be flushed in case the data written
is seen on a different mapping in user land on cache incoherent
architectures.
Signed-off-by: NSebastian Andrzej Siewior <sebastian@breakpoint.cc>
Acked-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NPierre Ossman <pierre@ossman.eu>

Commit d9c7d394
("block: prevent possible io_context->refcount overflow") mistakenly
changed atomic_inc(&ioc->nr_tasks) to atomic_long_inc(&ioc->refcount).
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NNikanth Karthikesan <knikanth@suse.de>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

I've been doing this for years, and akpm picked me up on it about 12
months ago.  lguest partly serves as example code, so let's do it Right.

Also, remove two unused fields in struct vblk_info in the example launcher.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>

I don't really notice it (except to begrudge the extra vertical
space), but Ingo does.  And he pointed out that one excuse of lguest
is as a teaching tool, it should set a good example.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>

To avoid userspace build failures such as:

.../linux/uio.h:37: error: expected `=', `,', `;', `asm' or `__attribute__' before `iov_length'
.../linux/uio.h:47: error: expected declaration specifiers or `...' before `size_t'

move uio functions inside a __KERNEL__ block.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Once a structure goes over PAGE_SIZE*2, we see occasional allocation
failures.  Some people have chosen to switch over to things like vmalloc()
that will let them keep array-like access to such a large structures.
But, vmalloc() has plenty of downsides.

Here's an alternative.  I think it's what Andrew was suggesting here:

	http://lkml.org/lkml/2009/7/2/518

I call it a flexible array.  It does all of its work in PAGE_SIZE bits, so
never does an order>0 allocation.  The base level has
PAGE_SIZE-2*sizeof(int) bytes of storage for pointers to the second level.
 So, with a 32-bit arch, you get about 4MB (4183112 bytes) of total
storage when the objects pack nicely into a page.  It is half that on
64-bit because the pointers are twice the size.  There's a table detailing
this in the code.

There are kerneldocs for the functions, but here's an
overview:

flex_array_alloc() - dynamically allocate a base structure
flex_array_free() - free the array and all of the
		    second-level pages
flex_array_free_parts() - free the second-level pages, but
			  not the base (for static bases)
flex_array_put() - copy into the array at the given index
flex_array_get() - copy out of the array at the given index
flex_array_prealloc() - preallocate the second-level pages
			between the given indexes to
			guarantee no allocs will occur at
			put() time.

We could also potentially just pass the "element_size" into each of the
API functions instead of storing it internally.  That would get us one
more base pointer on 32-bit.

I've been testing this by running it in userspace.  The header and patch
that I've been using are here, as well as the little script I'm using to
generate the size table which goes in the kerneldocs.

	http://sr71.net/~dave/linux/flexarray/

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NDave Hansen <dave@linux.vnet.ibm.com>
Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Found with make headers_check

/usr/include/linux/pps.h:52: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: NDave Jones <davej@redhat.com>
Cc: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After commit ec64f515 ("cgroup: fix
frequent -EBUSY at rmdir"), cgroup's rmdir (especially against memcg)
doesn't return -EBUSY by temporary ref counts.  That commit expects all
refs after pre_destroy() is temporary but...it wasn't.  Then, rmdir can
wait permanently.  This patch tries to fix that and change followings.

 - set CGRP_WAIT_ON_RMDIR flag before pre_destroy().
 - clear CGRP_WAIT_ON_RMDIR flag when the subsys finds racy case.
   if there are sleeping ones, wakes them up.
 - rmdir() sleeps only when CGRP_WAIT_ON_RMDIR flag is set.
Tested-by: NDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reported-by: NDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: NPaul Menage <menage@google.com>
Acked-by: NBalbir Sigh <balbir@linux.vnet.ibm.com>
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The bug was introduced by commit cc31edce
("cgroups: convert tasks file to use a seq_file with shared pid array").

We cache a pid array for all threads that are opening the same "tasks"
file, but the pids in the array are always from the namespace of the
last process that opened the file, so all other threads will read pids
from that namespace instead of their own namespaces.

To fix it, we maintain a list of pid arrays, which is keyed by pid_ns.
The list will be of length 1 at most time.
Reported-by: NPaul Menage <menage@google.com>
Idea-by: NPaul Menage <menage@google.com>
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Reviewed-by: NSerge Hallyn <serue@us.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We really don't want to mark the pty as a low-latency device, because as
Alan points out, the ->write method can be called from an IRQ (ppp?),
and that means we can't use ->low_latency=1 as we take mutexes in the
low_latency case.

So rather than using low_latency to force the written data to be pushed
to the ldisc handling at 'write()' time, just make the reader side (or
the poll function) do the flush when it checks whether there is data to
be had.

This also fixes the problem with lost data in an emacs compile buffer
(bugzilla 13815), and we can thus revert the low_latency pty hack
(commit 3a542974: "pty: quickfix for the
pty ENXIO timing problems").
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Tested-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[ Modified to do the tty_flush_to_ldisc() inside input_available_p() so
  that it triggers for both read and poll()  - Linus]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Create bdgrab().  This function copies an existing reference to a
block_device.  It is safe to call from any context.

Hibernation code wishes to copy a reference to the active swap device.
Right now it calls bdget() under a spinlock, but this is wrong because
bdget() can sleep.  It doesn't need a full bdget() because we already
hold a reference to active swap devices (and the spinlock protects
against swapoff).

Fixes http://bugzilla.kernel.org/show_bug.cgi?id=13827Signed-off-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

On certain configurations, HPA isn't or can't be unlocked during
probing but it somehow ends up unlocked afterwards.  In the following
thread, the problem can be reliably reproduced after resuming from
STR.  The BIOS turns on HPA during boot but forgets to do it during
resume.

  http://thread.gmane.org/gmane.linux.kernel/858310

This patch updates libata revalidation such that it considers native
n_sectors.  If the device size has increased to match native
n_sectors, it's assumed that HPA has been unlocked involuntarily and
the device is recognized as the same one.  This should be fairly safe
while nicely working around the problem.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NChristof Warlich <christof@warlich.name>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>