Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace

Impact: clean up

kcalloc is a better approach to allocate a NULL array.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace

Conflicts:
	kernel/sched_clock.c

Conflicts:
	kernel/sched_clock.c

Impact: clean up

Instead of listing the trace options like:

 # cat /debug/tracing/trace_options
print-parent nosym-offset nosym-addr noverbose noraw nohex nobin noblock nostacktrace nosched-tree ftrace_printk noftrace_preempt nobranch annotate nouserstacktrace nosym-userobj

We now list them like:

 # cat /debug/tracing/trace_options
print-parent
nosym-offset
nosym-addr
noverbose
noraw
nohex
nobin
noblock
nostacktrace
nosched-tree
ftrace_printk
noftrace_preempt
nobranch
annotate
nouserstacktrace
nosym-userobj
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Impact: fix compile warning and clean up

When I first wrote __tracing_open, instead of passing the error
code via the ERR_PTR macros, I lazily used a separate parameter
to hold the return for errors.

When Frederic Weisbecker updated that function, he used the Linux
kernel ERR_PTR for the returns. This caused the parameter return
to possibly not be initialized on error. gcc correctly pointed this
out with a warning.

This patch converts the entire function to use the Linux kernel
ERR_PTR macro methods.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Impact: fix to possible race conditions

There's some uses of current_tracer that is not protected by the
trace_types_lock. There is a small chance that a sysadmin changes
the tracer while the current_tracer is being referenced.

If the race is hit, it is unlikely to cause any harm since the
tracers are constant and are not freed. But some strang side
effects may occur.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

This patch adds the tracer dependent options dynamically to the
options directory when the tracer is activated. These options are
removed when the tracer is deactivated.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

This patch creates an options directory in the debugfs, that contains
the available tracing options. These files contain 1 or 0, where 1
is the option is enabled and 0 it is disabled.

Simply echoing in 1 will enable the option and 0 will disable it.
This patch only contains the core options, not the tracer options.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Conflicts:
	kernel/sched_clock.c

If the TSC is constant and non-stop, also set it reliable.

(We will turn this off in DMI quirks for multi-chassis systems)

The performance number on a 16-way Nehalem system running
32 tasks that context-switch between each other is significant:

   sched_clock_stable=0		sched_clock_stable=1
   ....................         ....................
   22.456925 million/sec        24.306972 million/sec   [+8.2%]

lmbench's "lat_ctx -s 0 2" goes from 0.63 microseconds to
0.59 microseconds - a 6.7% increase in context-switching
performance.

Perfstat of 1 million pipe context switches between two tasks:

 Performance counter stats for './pipe-test-1m':

       [before]           [after]
   ............      ............
   37621.421089      36436.848378    task clock ticks     (msecs)

              0                 0    CPU migrations       (events)
        2000274           2000189    context switches     (events)
            194               193    pagefaults           (events)
     8433799643        8171016416    CPU cycles           (events) -3.21%
     8370133368        8180999694    instructions         (events) -2.31%
        4158565           3895941    cache references     (events) -6.74%
          44312             46264    cache misses         (events)

    2349.287976       2279.362465    wall-time            (msecs)  -3.06%

The speedup comes straight from the reduction in the instruction
count. sched_clock_cpu() got simpler and the whole workload thus
executes faster.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Allow CONFIG_HAVE_UNSTABLE_SCHED_CLOCK architectures to still specify
that their sched_clock() implementation is reliable.

This will be used by x86 to switch on a faster sched_clock_cpu()
implementation on certain CPU types.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: try committing transaction before returning ENOSPC
  Btrfs: add better -ENOSPC handling

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  xen/blkfront: use blk_rq_map_sg to generate ring entries
  block: reduce stack footprint of blk_recount_segments()
  cciss: shorten 30s timeout on controller reset
  block: add documentation for register_blkdev()
  block: fix bogus gcc warning for uninitialized var usage

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: Fix 64bit __copy_tofrom_user() regression
  powerpc: Fix 64bit memcpy() regression
  powerpc: Fix load/store float double alignment handler

It needs to happen before any firewire driver actually registers itself,
and that was previously handled by having the Makefile list the core
ieee1394 files before the drivers.

But now there are firewire drivers in drivers/media, and the Makefile
games aren't enough.  So just make ieee1394_init happen earlier in the
init sequence, the way all other bus layers already do.
Reported-and-tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Henrik Kurelid <henrik@kurelid.se>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Ben Backx <ben@bbackx.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Impact: implement new tracing timestamp APIs

Add three trace clock variants, with differing scalability/precision
tradeoffs:

 -   local: CPU-local trace clock
 -  medium: scalable global clock with some jitter
 -  global: globally monotonic, serialized clock

Make the ring-buffer use the local trace clock internally.
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

make sure we dont execute more complex sched_clock() code in NMI context.
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: add new tracepoints

Add them to the generic IRQ code, that way every architecture
gets these new tracepoints, not just x86.

Using Steve's new 'TRACE_FORMAT', I can get function graph
trace as follows using the original two IRQ tracepoints:

 3)               |    handle_IRQ_event() {
 3)               |    /* (irq_handler_entry) irq=28 handler=eth0 */
 3)               |    e1000_intr_msi() {
 3)   2.460 us    |      __napi_schedule();
 3)   9.416 us    |    }
 3)               |    /* (irq_handler_exit) irq=28 handler=eth0 return=handled */
 3) + 22.935 us   |  }
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: restructure the VFS layout of per CPU trace buffers

The per cpu trace files are all in a single directory:
/debug/tracing/per_cpu. In case of a large number of cpu, the
content of this directory becomes messy so we create now one
directory per cpu inside /debug/tracing/per_cpu which contain
each their own trace_pipe and trace files.

Ie:

 /debug/tracing$ ls -R per_cpu
 per_cpu:
 cpu0  cpu1

 per_cpu/cpu0:
 trace  trace_pipe

 per_cpu/cpu1:
 trace  trace_pipe
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

On occasion, the request will apparently have more segments than we
fit into the ring. Jens says:

> The second problem is that the block layer then appears to create one
> too many segments, but from the dump it has rq->nr_phys_segments ==
> BLKIF_MAX_SEGMENTS_PER_REQUEST. I suspect the latter is due to
> xen-blkfront not handling the merging on its own. It should check that
> the new page doesn't form part of the previous page. The
> rq_for_each_segment() iterates all single bits in the request, not dma
> segments. The "easiest" way to do this is to call blk_rq_map_sg() and
> then iterate the mapped sg list. That will give you what you are
> looking for.

> Here's a test patch, compiles but otherwise untested. I spent more
> time figuring out how to enable XEN than to code it up, so YMMV!
> Probably the sg list wants to be put inside the ring and only
> initialized on allocation, then you can get rid of the sg on stack and
> sg_init_table() loop call in the function. I'll leave that, and the
> testing, to you.

[Moved sg array into info structure, and initialize once. -J]
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

blk_recalc_rq_segments() requires a request structure passed in, which
we don't have from blk_recount_segments(). So the latter allocates one on
the stack, using > 400 bytes of stack for that. This can cause us to spill
over one page of stack from ext4 at least:

 0)     4560     400   blk_recount_segments+0x43/0x62
 1)     4160      32   bio_phys_segments+0x1c/0x24
 2)     4128      32   blk_rq_bio_prep+0x2a/0xf9
 3)     4096      32   init_request_from_bio+0xf9/0xfe
 4)     4064     112   __make_request+0x33c/0x3f6
 5)     3952     144   generic_make_request+0x2d1/0x321
 6)     3808      64   submit_bio+0xb9/0xc3
 7)     3744      48   submit_bh+0xea/0x10e
 8)     3696     368   ext4_mb_init_cache+0x257/0xa6a [ext4]
 9)     3328     288   ext4_mb_regular_allocator+0x421/0xcd9 [ext4]
10)     3040     160   ext4_mb_new_blocks+0x211/0x4b4 [ext4]
11)     2880     336   ext4_ext_get_blocks+0xb61/0xd45 [ext4]
12)     2544      96   ext4_get_blocks_wrap+0xf2/0x200 [ext4]
13)     2448      80   ext4_da_get_block_write+0x6e/0x16b [ext4]
14)     2368     352   mpage_da_map_blocks+0x7e/0x4b3 [ext4]
15)     2016     352   ext4_da_writepages+0x2ce/0x43c [ext4]
16)     1664      32   do_writepages+0x2d/0x3c
17)     1632     144   __writeback_single_inode+0x162/0x2cd
18)     1488      96   generic_sync_sb_inodes+0x1e3/0x32b
19)     1392      16   sync_sb_inodes+0xe/0x10
20)     1376      48   writeback_inodes+0x69/0xb3
21)     1328     208   balance_dirty_pages_ratelimited_nr+0x187/0x2f9
22)     1120     224   generic_file_buffered_write+0x1d4/0x2c4
23)      896     176   __generic_file_aio_write_nolock+0x35f/0x393
24)      720      80   generic_file_aio_write+0x6c/0xc8
25)      640      80   ext4_file_write+0xa9/0x137 [ext4]
26)      560     320   do_sync_write+0xf0/0x137
27)      240      48   vfs_write+0xb3/0x13c
28)      192      64   sys_write+0x4c/0x74
29)      128     128   system_call_fastpath+0x16/0x1b

Split the segment counting out into a __blk_recalc_rq_segments() helper
to avoid allocating an onstack request just for checking the physical
segment count.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

If reset_devices is set for kexec, then cciss will delay 30 seconds
since the old 5i controller _may_ need that long to recover. Replace
the long sleep with incremental sleep and tests to reduce the 30 seconds
to worst case for 5i, so that other controllers will proceed quickly.
Reviewed-by: Mike Miller <mike.miller@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Add documentation for register_blkdev() function and for the parameters.
Signed-off-by: Márton Németh <nm127@freemail.hu>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Newer gcc throw this warning:

        fs/bio.c: In function ?bio_alloc_bioset?:
        fs/bio.c:305: warning: ?p? may be used uninitialized in this function

since it cannot figure out that 'p' is only ever used if 'bs' is non-NULL.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

This fixes a regression introduced by commit
a4e22f02 ("powerpc: Update 64bit
__copy_tofrom_user() using CPU_FTR_UNALIGNED_LD_STD").

The same bug that existed in the 64bit memcpy() also exists here so fix
it here too. The fix is the same as that applied to memcpy() with the
addition of fixes for the exception handling code required for
__copy_tofrom_user().

This stops us reading beyond the end of the source region we were told
to copy.
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This fixes a regression introduced by commit
25d6e2d7 ("powerpc: Update 64bit memcpy()
using CPU_FTR_UNALIGNED_LD_STD").

This commit allowed CPUs that have the CPU_FTR_UNALIGNED_LD_STD CPU
feature bit present to do the memcpy() with unaligned load doubles. But,
along with this came a bug where our final load double would read bytes
beyond a page boundary and into the next (unmapped) page. This was caught
by enabling CONFIG_DEBUG_PAGEALLOC,

The fix was to read only the number of bytes that we need to store rather
than reading a full 8-byte doubleword and storing only a portion of that.

In order to minimise the amount of existing code touched we use the
original do_tail for the src_unaligned case.

Below is an example of the regression, as reported by Sachin Sant:

Unable to handle kernel paging request for data at address 0xc00000003f380000
Faulting instruction address: 0xc000000000039574
cpu 0x1: Vector: 300 (Data Access) at [c00000003baf3020]
    pc: c000000000039574: .memcpy+0x74/0x244
    lr: d00000000244916c: .ext3_xattr_get+0x288/0x2f4 [ext3]
    sp: c00000003baf32a0
   msr: 8000000000009032
   dar: c00000003f380000
 dsisr: 40000000
  current = 0xc00000003e54b010
  paca    = 0xc000000000a53680
    pid   = 1840, comm = readahead
enter ? for help
[link register   ] d00000000244916c .ext3_xattr_get+0x288/0x2f4 [ext3]
[c00000003baf32a0] d000000002449104 .ext3_xattr_get+0x220/0x2f4 [ext3]
(unreliab
le)
[c00000003baf3390] d00000000244a6e8 .ext3_xattr_security_get+0x40/0x5c [ext3]
[c00000003baf3400] c000000000148154 .generic_getxattr+0x74/0x9c
[c00000003baf34a0] c000000000333400 .inode_doinit_with_dentry+0x1c4/0x678
[c00000003baf3560] c00000000032c6b0 .security_d_instantiate+0x50/0x68
[c00000003baf35e0] c00000000013c818 .d_instantiate+0x78/0x9c
[c00000003baf3680] c00000000013ced0 .d_splice_alias+0xf0/0x120
[c00000003baf3720] d00000000243e05c .ext3_lookup+0xec/0x134 [ext3]
[c00000003baf37c0] c000000000131e74 .do_lookup+0x110/0x260
[c00000003baf3880] c000000000134ed0 .__link_path_walk+0xa98/0x1010
[c00000003baf3970] c0000000001354a0 .path_walk+0x58/0xc4
[c00000003baf3a20] c000000000135720 .do_path_lookup+0x138/0x1e4
[c00000003baf3ad0] c00000000013645c .path_lookup_open+0x6c/0xc8
[c00000003baf3b70] c000000000136780 .do_filp_open+0xcc/0x874
[c00000003baf3d10] c0000000001251e0 .do_sys_open+0x80/0x140
[c00000003baf3dc0] c00000000016aaec .compat_sys_open+0x24/0x38
[c00000003baf3e30] c00000000000855c syscall_exit+0x0/0x40
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

When we introduced VSX, we changed the way FPRs are stored in the
thread_struct.  Unfortunately we missed the load/store float double
alignment handler code when updating how we access FPRs in the
thread_struct.

Below fixes this and merges the little/big endian case.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Merge branch 'tip/tracing/ftrace' of ssh://master.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace

Peter Zijlstra warned that TPPROTO and TPARGS might become something
other than a simple copy of itself. To prevent this from having
side effects in the TRACE_FORMAT macro in tracepoint.h, we add a
PARAMS() macro to be defined as just a wrapper.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

There's been a bit confusion to whether DEFINE/DECLARE_TRACE_FMT should
be a DEFINE or a DECLARE. Ingo Molnar suggested simply calling it
TRACE_FORMAT.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: emu10k1 - Fix digital/analog switch on audigy2 ZS
  ALSA: hda - Quirk for Acer Aspire 6530G
  ALSA: hda - add another MacBook Pro 3,1 SSID
  ALSA: fix excessive background noise introduced by OSS emulation rate shrink
  ALSA: aw2: do not grab every saa7146 based device
  ALSA: hda - Fix parse of init_verbs sysfs entry
  ALSA: pcxhr.h replace signed one-bit bitfields

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] Don't go beyond iosapic_intr_info's arraysize
  [IA64] Do not go beyond ARRAY_SIZE of unw.hash
  [IA64] enable setting DMAR on by default

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  [libata] pata_legacy: for VLB 32bit PIO don't try tricks with slop
  [libata] pata_amd: program FIFO
  sata_mv: fix SoC interrupt breakage
  pata_it821x: resume from hibernation fails with RAID volume

These devices are generally used with ATA anyway and it seems that some
ATAPI will need us to issue the right number of words.  Therefore as we
can't switch mid burst on VLB devices we should only use 32bit I/O for
suitable block sizes.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

With 32bit PIO we can use the posted write buffers, but only for 32bit I/O
cycles.  This means we must disable the FIFO for ATAPI where a final 16bit
cycle may occur.

Rework the FIFO logic so that we disable the FIFO then selectively
re-enable it when we set the timings on AMD devices.  Also fix a case
where we scribbled on PCI config 0x41 of Nvidia chips when we shouldn't.
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

For some reason, sata_mv doesn't clear interrupt status during init
when it's running on an SoC host adapter.  If the bootloader has
touched the SATA controller before starting Linux, Linux can end up
enabling the SATA interrupt with events pending, which will cause the
interrupt to be marked as spurious and then be disabled, which then
breaks all further accesses to the controller.

This patch makes the SoC path clear interrupt status on init like in
the non-SoC case.
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Hibernation didn't work for me since I started to use IT8212 controller.
I did some debugging (booting with no_console_suspend init=/bin/sh).

Found that resume fails (2.6.28) with "serial number mismatch 'some
garbage' != 'some other garbage'" and "revalidation failed" messages.
That's because the controller firmware fills different serial number in
the IDENTIFY every boot.

The patch below fixes the resume simply clearing the serial number.  The
proper fix would be probably to fill in the serial number of the RAID
volume instead.  I assume that there must be something like that stored on
the drives but I don't know where.

Fix resume on pata_it821x RAID volume by clearing the serial number in
IDENTIFY data, which is otherwise different on each boot.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>