Add two events lock_kernel and unlock_kernel() to trace the bkl uses.
This opens the door for userspace tools to perform statistics about
the callsites that use it, dependencies with other locks (by pairing
the trace with lock events), use with recursivity and so on...

The {__reacquire,release}_kernel_lock() events are not traced because
these are called from schedule, thus the sched events are sufficient
to trace them.

Example of a trace:

hald-addon-stor-4152  [000]   165.875501: unlock_kernel: depth: 0, fs/block_dev.c:1358 __blkdev_put()
hald-addon-stor-4152  [000]   167.832974: lock_kernel: depth: 0, fs/block_dev.c:1167 __blkdev_get()

How to get the callsites that acquire it recursively:

cd /debug/tracing/events/bkl
echo "lock_depth > 0" > filter

firefox-4951  [001]   206.276967: unlock_kernel: depth: 1, fs/reiserfs/super.c:575 reiserfs_dirty_inode()

You can also filter by file and/or line.

v2: Use of FILTER_PTR_STRING attribute for files and lines fields to
    make them traceable.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>

Remove the duplicate comment of bstr_printf that is the same as the
vsnprintf.

Add the 's' option to the comment for the pointer function. This is
more of an internal function so the little duplication of the comment
here is OK.
Reported-by: Zhaolei <zhaolei@cn.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

With BLOCK_IOPOLL_SOFTIRQ added, softirq_to_name[] and
show_softirq_name() needs to be updated.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4AB20398.8070209@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

commit 85bac32c
    ring-buffer: only enable ring_buffer_swap_cpu when needed
broke oprofile (at least on s390, but likely on all platforms).

this patch lets oprofile select RING_BUFER_ALLOW_SWAP to make
ring_buffer_swap_cpu usable for oprofile.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
LKML-Reference: <200909162156.49239.borntraeger@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Robert Richter <robert.richter@amd.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

For direct function pointers (like what mcount provides) PowerPC64
requires the use of %ps, otherwise nothing is printed.

This patch converts all prints of functions retrieved through mcount
to use the %ps format from the %pf.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

On PowerPC64 function pointers do not point directly at the functions,
but instead point to pointers to the functions. The output of %pF expects
to point to a pointer to the function, whereas %pS will show the function
itself.

mcount returns the direct pointer to the function and not the pointer to
the pointer. Thus %pS must be used to show this. The function tracer
requires printing of the functions without offsets and uses the %pf
instead.

 %pF produces run_local_timers+0x4/0x1f
 %pf produces just run_local_timers

For PowerPC64, we need to use the direct pointer, and we only have
%pS which will produce .run_local_timers+0x4/0x1f

This patch creates a %ps that matches the %pf as %pS matches %pF.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Zhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Merge reason: Pick up kernel/softirq.c update for dependent fix.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Merge branch 'tip/tracing/core4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/core

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev
  debugfs: Modify default debugfs directory for debugging pktcdvd.
  debugfs: Modified default dir of debugfs for debugging UHCI.
  debugfs: Change debugfs directory of IWMC3200
  debugfs: Change debuhgfs directory of trace-events-sample.h
  debugfs: Fix mount directory of debugfs by default in events.txt
  hpilo: add poll f_op
  hpilo: add interrupt handler
  hpilo: staging for interrupt handling
  driver core: platform_device_add_data(): use kmemdup()
  Driver core: Add support for compatibility classes
  uio: add generic driver for PCI 2.3 devices
  driver-core: move dma-coherent.c from kernel to driver/base
  mem_class: fix bug
  mem_class: use minor as index instead of searching the array
  driver model: constify attribute groups
  UIO: remove 'default n' from Kconfig
  Driver core: Add accessor for device platform data
  Driver core: move dev_get/set_drvdata to drivers/base/dd.c
  Driver core: add new device to bus's list before probing

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6: (641 commits)
  Staging: remove sxg driver
  Staging: remove heci driver
  Staging: remove at76_usb wireless driver.
  Staging: rspiusb: remove the driver
  Staging: meilhaus: remove the drivers
  Staging: remove me4000 driver.
  Staging: line6: ffzb returns an unsigned integer
  Staging: line6: pod.c: style cleanups
  Staging: iio: introduce missing kfree
  Staging: dream: introduce missing kfree
  Staging: comedi: addi-data: NULL dereference of amcc in v_pci_card_list_init()
  Staging: vt665x: fix built-in compiling
  Staging: rt3090: enable NATIVE_WPA_SUPPLICANT_SUPPORT option
  Staging: rt3090: port changes in WPA_MIX_PAIR_CIPHER to rt3090
  Staging: rt3090: rename device from raX to wlanX
  Staging: rt3090: remove possible conflict with rt2860
  Staging: rt2860/rt2870/rt3070/rt3090: fix compiler warning on x86_64
  Staging: rt2860: add new device ids
  Staging: rt3090: add device id 1462:891a
  Staging: asus_oled: Cleaned up checkpatch issues.
  ...

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/pcmcia-2.6:
  pcmcia: document return value of pcmcia_loop_config
  pcmcia: dtl1_cs: fix pcmcia_loop_config logic
  pcmcia: drop non-existant includes
  pcmcia: disable prefetch/burst for OZ6933
  pcmcia: fix incorrect argument order to list_add_tail()
  pcmcia: drivers/pcmcia/pcmcia_resource.c: Remove unnecessary semicolons
  pcmcia: Use phys_addr_t for physical addresses
  pcmcia: drivers/pcmcia: Make static

* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (75 commits)
  PCI hotplug: clean up acpi_run_hpp()
  PCI hotplug: acpiphp: use generic pci_configure_slot()
  PCI hotplug: shpchp: use generic pci_configure_slot()
  PCI hotplug: pciehp: use generic pci_configure_slot()
  PCI hotplug: add pci_configure_slot()
  PCI hotplug: clean up acpi_get_hp_params_from_firmware() interface
  PCI hotplug: acpiphp: don't cache hotplug_params in acpiphp_bridge
  PCI hotplug: acpiphp: remove superfluous _HPP/_HPX evaluation
  PCI: Clear saved_state after the state has been restored
  PCI PM: Return error codes from pci_pm_resume()
  PCI: use dev_printk in quirk messages
  PCI / PCIe portdrv: Fix pcie_portdrv_slot_reset()
  PCI Hotplug: convert acpi_pci_detect_ejectable() to take an acpi_handle
  PCI Hotplug: acpiphp: find bridges the easy way
  PCI: pcie portdrv: remove unused variable
  PCI / ACPI PM: Propagate wake-up enable for devices w/o ACPI support
  ACPI PM: Replace wakeup.prepared with reference counter
  PCI PM: Introduce device flag wakeup_prepared
  PCI / ACPI PM: Rework some debug messages
  PCI PM: Simplify PCI wake-up code
  ...

Fixed up conflict in arch/powerpc/kernel/pci_64.c due to OF device tree
scanning having been moved and merged for the 32- and 64-bit cases.  The
'needs_freset' initialization added in 6e19314c ("PCI/powerpc: support
PCIe fundamental reset") is now in arch/powerpc/kernel/pci_of_scan.c.

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  block: fix linkage problem with blk_iopoll and !CONFIG_BLOCK

* 'writeback' of git://git.kernel.dk/linux-2.6-block:
  writeback: fix possible bdi writeback refcounting problem
  writeback: Fix bdi use after free in wb_work_complete()
  writeback: improve scalability of bdi writeback work queues
  writeback: remove smp_mb(), it's not needed with list_add_tail_rcu()
  writeback: use schedule_timeout_interruptible()
  writeback: add comments to bdi_work structure
  writeback: splice dirty inode entries to default bdi on bdi_destroy()
  writeback: separate starting of sync vs opportunistic writeback
  writeback: inline allocation failure handling in bdi_alloc_queue_work()
  writeback: use RCU to protect bdi_list
  writeback: only use bdi_writeback_all() for WB_SYNC_NONE writeout
  fs: Assign bdi in super_block
  writeback: make wb_writeback() take an argument structure
  writeback: merely wakeup flusher thread if work allocation fails for WB_SYNC_NONE
  writeback: get rid of wbc->for_writepages
  fs: remove bdev->bd_inode_backing_dev_info

wb_clear_pending AFAIKS should not be called after the item has been
put on the list, except by the worker threads. It could lead to the
situation where the refcount is decremented below 0 and cause lots of
problems.

Presumably the !wb_has_dirty_io case is not a common one, so it can
be discovered when the thread wakes up to check?

Also add a comment in bdi_work_clear.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

By the time bdi_work_on_stack gets evaluated again in bdi_work_free, it
can already have been deallocated and used for something else in the
!on stack case, giving a false positive in this test and causing
corruption.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

If you're going to do an atomic RMW on each list entry, there's not much
point in all the RCU complexities of the list walking. This is only going
to help the multi-thread case I guess, but it doesn't hurt to do now.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

list_add_tail_rcu contains required barriers.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Gets rid of a manual set_current_state().
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

And document its retriever, get_next_work_item().
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

We cannot safely ensure that the inodes are all gone at this point
in time, and we must not destroy this bdi with inodes having off it.
So just splice our entries to the default bdi since that one will
always persist.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

bdi_start_writeback() is currently split into two paths, one for
WB_SYNC_NONE and one for WB_SYNC_ALL. Add bdi_sync_writeback()
for WB_SYNC_ALL writeback and let bdi_start_writeback() handle
only WB_SYNC_NONE.

Push down the writeback_control allocation and only accept the
parameters that make sense for each function. This cleans up
the API considerably.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

This gets rid of work == NULL in bdi_queue_work() and puts the
OOM handling where it belongs.
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Now that bdi_writeback_all() no longer handles integrity writeback,
it doesn't have to block anymore. This means that we can switch
bdi_list reader side protection to RCU.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Data integrity writeback must use bdi_start_writeback() and ensure
that wbc->sb and wbc->bdi are set.
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

We do this automatically in get_sb_bdev() from the set_bdev_super()
callback. Filesystems that have their own private backing_dev_info
must assign that in ->fill_super().

Note that ->s_bdi assignment is required for proper writeback!
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

We need to be able to pass in range_cyclic as well, so instead
of growing yet another argument, split the arguments into a
struct wb_writeback_args structure that we can use internally.
Also makes it easier to just copy all members to an on-stack
struct, since we can't access work after clearing the pending
bit.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Since it's an opportunistic writeback and not a data integrity action,
don't punt to blocking writeback. Just wakeup the thread and it will
flush old data.
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

It's only set, it's never checked. Kill it.
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

It has been unused since it was introduced in:

commit 520808bf
Author: Andrew Morton <akpm@osdl.org>
Date:   Fri May 21 00:46:17 2004 -0700

    [PATCH] block device layer: separate backing_dev_info infrastructure

So lets just kill it.
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Fix the condition of strcmp for "*".
Also fix NULL pointer dereference when glob is NULL.
Signed-off-by: Atsushi Tsuji <a-tsuji@bk.jp.nec.com>
LKML-Reference: <4AAF6726.5090905@bk.jp.nec.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

When ftrace had issues with NMIs, it was needed to annotate all
the areas that kprobes had issues with notrace. Now that ftrace is
NMI safe, the functions that limit ftrace from tracing are just a
small few.

Kprobes is too big of a set for ftrace not to trace. Remove the
coupling.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

 kernel/built-in.o:(.data+0x17b0): undefined reference to `blk_iopoll_enabled'

Since the extern declaration makes the compile work, but the actual
symbol is missing when block/blk-iopoll.o isn't linked in.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

This build bug:

 mm/slub.c: In function 'kmem_cache_open':
 mm/slub.c:2476: error: 'disable_higher_order_debug' undeclared (first use in this function)
 mm/slub.c:2476: error: (Each undeclared identifier is reported only once
 mm/slub.c:2476: error: for each function it appears in.)

Triggers because there's no !CONFIG_SLUB_DEBUG definition for
disable_higher_order_debug.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

Unfortunatly, the upstream company has abandonded development of this
driver.  So it's best to just remove the driver from the tree.

Cc: Christopher Harrer <charrer@alacritech.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Intel has officially abandoned this project and does not want to
maintian it or have it included in the main kernel tree, as no one
should use the code, it's not needed anymore.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

There is already an in-kernel driver for this hardware (since 2.6.30),
at76c50x-usb, and it supports all of the same devices.  So this driver
can now be deleted.

Acked-by: Kalle Valo <kalle.valo@iki.fi> 
Cc: linux-wireless <linux-wireless@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

No one cares, it's a custom userspace interface, and the code hasn't
built in a long time.  So remove it.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The comedi drivers should be used instead, no need to have
these in here as well.

Cc: David Kiliani <mail@davidkiliani.de>
Cc: Meilhaus Support <support@meilhaus.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The comedi drivers should be used instead, no need to have
this driver in the tree duplicating that one.

Cc: Wolfgang Beiter <w.beiter@aon.at>
Cc: Guenter Gebhardt <g.gebhardt@meilhaus.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>