Commit graph

175907 commits

Author SHA1 Message Date
Jean Delvare
4710317891 i2c-stub: Implement I2C block support
This is required to test some drivers, for example at24.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:28 +01:00
Jean Delvare
69b0089a67 i2c: Refactor for_each callbacks
Functions i2c_do_add_adapter() and __attach_adapter() do essentially
the same thing, differing only in how the parameters are passed. Same
for i2c_do_add_adapter() and __detach_adapter(). Introduce wrappers to
normalize the parameters, so that we do not have to duplicate the
code.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-12-06 17:06:27 +01:00
Jean Delvare
7e2193a8f9 i2c-i801: Retry on lost arbitration
The Intel 82801 is sometimes used on systems with a BMC connected. The
BMC can access the SMBus, resulting in lost arbitration for the 82801.
We should let i2c-core retry transactions for us in this case.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:27 +01:00
Vincent Sanders
9669f54194 i2c: Remove big kernel lock from i2cdev_open
The BKL is held over a kmalloc so cannot protect anything beyond that.
The two calls before the kmalloc have their own locking.
Improve device open function by removing the now unnecessary ret variable

Signed-off-by: Vincent Sanders <vince@simtec.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:26 +01:00
Jean Delvare
c2e90e9b68 ics932s401: Clean up detect function
As kind is now hard-coded to -1, there is room for code clean-ups.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: "Darrick J. Wong" <djwong@us.ibm.com>
2009-12-06 17:06:26 +01:00
Jean Delvare
ccfbbd082a i2c: Simplify i2c_detect_address
The kind parameter of i2c_detect_address() always has value -1, so we
can get rid of it.

Next step is to update all i2c detect callback functions to get rid of
this now useless parameter.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:25 +01:00
Jean Delvare
c7b25a9e96 i2c: Drop probe, ignore and force module parameters
The legacy probe and force module parameters are obsolete now, the
same can be achieved using the new_device sysfs interface, which is
both more flexible and cheaper (it is implemented by i2c-core rather
than replicated in every driver module.)

The legacy ignore module parameters can be dropped as well. Ignoring
can be done by instantiating a "dummy" device at the problematic
address.

This is the first step of a huge cleanup to i2c-core's i2c_detect
function, i2c.h's I2C_CLIENT_INSMOD* macros, and all drivers that made
use of them.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:24 +01:00
Jean Delvare
abe38388e5 i2c: Add missing __devinit markers to old i2c adapter drivers
These _setup functions are called from _probe so they can be marked
__devinit.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:23 +01:00
Jean Delvare
da44bdeb95 i2c: Bus drivers don't have to support I2C_M_REV_DIR_ADDR
I2C bus drivers don't have to support I2C_M_REV_DIR_ADDR. It is a
deviation from the I2C specification, which only makes sense to
implement when really needed.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Ben Dooks <ben-linux@fluff.org>
2009-12-06 17:06:22 +01:00
Mika Kuoppala
194684e596 i2c: Prevent priority inversion on top of bus lock
Low priority thread holding the i2c bus mutex could block higher
priority threads to access the bus resulting in unacceptable
latencies. Change the mutex type to rt_mutex preventing priority
inversion.

Tested-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@nokia.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:22 +01:00
Jean Delvare
a0c11cdd6a i2c-voodoo3: Delete
Superseded by tdfxfb. I2C/DDC support used to live in a separate
driver but this caused driver conflicts.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Krzysztof Helt <krzysztof.h1@wp.pl>
2009-12-06 17:06:21 +01:00
Jean Delvare
bc6286e50b i2c-powermac: Drop temporary name buffer
We no longer need to write the adapter name to a temporary buffer.
We can write it directly to the i2c_adapter's name field. This is
more efficient.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Michel Daenzer <michel@daenzer.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-12-06 17:06:20 +01:00
Jean Delvare
6dfa5ca3c9 i2c-powermac: Include the i2c_adapter in struct pmac_i2c_bus
Include the i2c_adapter in struct pmac_i2c_bus. This avoids memory
fragmentation and allows for several code cleanups.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Michel Daenzer <michel@daenzer.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-12-06 17:06:19 +01:00
Jean Delvare
d7d838a6eb i2c-powermac: Log errors
Log errors when they happen, otherwise we have no idea what went
wrong.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Michel Daenzer <michel@daenzer.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
2009-12-06 17:06:18 +01:00
Jean Delvare
02864d58ce i2c-powermac: Refactor i2c_powermac_smbus_xfer
I wanted to add some error logging to the i2c-powermac driver, but
found that it was very difficult due to the way the
i2c_powermac_smbus_xfer function is organized. Refactor the code in
this function so that each low-level function is only called once.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Michel Daenzer <michel@daenzer.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
2009-12-06 17:06:17 +01:00
Jean Delvare
6f7e549f87 i2c-powermac: Reject unsupported I2C transactions
The i2c-powermac driver doesn't support arbitrary multi-message I2C
transactions, only SMBus ones. Make it clear by returning an error if
a multi-message I2C transaction is attempted. This is better than only
processing the first message, because most callers won't recover from
the short transaction. Anyone wishing to issue multi-message
transactions should use the SMBus API instead of the raw I2C API.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Michel Daenzer <michel@daenzer.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
2009-12-06 17:06:17 +01:00
Wolfram Sang
dddc66ffa0 i2c/chips: Move ds1682 to drivers/misc
As i2c/chips is deprecated, move ds1682 to a more apropriate location.
Build tested.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:16 +01:00
Rafael J. Wysocki
7a1a8eb58a PM: Add flag for devices capable of generating run-time wake-up events
Apparently, there are devices that can wake up the system from sleep
states and yet are incapable of generating wake-up events at run
time.  Thus, introduce a flag indicating if given device is capable
of generating run-time wake-up events.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-12-06 16:17:57 +01:00
Rafael J. Wysocki
965c4ac061 PM / Runtime: Remove unnecessary braces in __pm_runtime_set_status()
Some braces in __pm_runtime_set_status() are not necessary, so
remove them.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-12-06 16:17:57 +01:00
Rafael J. Wysocki
e1b1903eee PM / Runtime: Make documentation of runtime_idle() agree with the code
Currently the ->runtime_idle() callback is documented as having no
return value, but in fact it returns int.  Although its return value
is ignored at the PM core level, it may be used by bus type routines
executing the drivers' ->runtime_idle() callbacks.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
2009-12-06 16:17:57 +01:00
Rafael J. Wysocki
0ddf0ed1d4 PM / Runtime: Ensure timer_expires is nonzero in pm_schedule_suspend()
The runtime PM core code assumes that dev->power.timer_expires is
nonzero when the timer is scheduled, but it may become zero
incidentally in pm_schedule_suspend().  Prevent this from happening
by bumping dev->power.timer_expires up to 1 if it's 0 before calling
mod_timer().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
2009-12-06 16:17:56 +01:00
Alan Stern
63c9480170 PM / Runtime: Use deferred_resume flag in pm_request_resume
This patch (as1307) adds a small optimization to
__pm_request_resume().  If the device is currently being suspended,
there's no need to queue a work routine to resume it.  Setting the
deferred_resume flag will suffice.  (There's also a minor improvement
to the function's code layout: An unnecessary "else" is removed.)

Also, the patch clarifies the usage of the deferred_resume flag.  It
is meaningful only while a suspend is in progress, so it should be
cleared just before a suspend starts, not just after one ends.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-12-06 16:17:56 +01:00
Alan Stern
7b199ca202 PM / Runtime: Export the PM runtime workqueue
This patch (as1306) exports the PM runtime workqueue for use by
loadable modules.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-12-06 16:17:56 +01:00
Rafael J. Wysocki
bab636b921 PM / Runtime: Fix lockdep warning in __pm_runtime_set_status()
Lockdep complains about taking the parent lock in
__pm_runtime_set_status(), so mark it as nested.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@kernel.org
2009-12-06 16:17:56 +01:00
Jiri Slaby
66d0ae4d6f PM / Hibernate: Swap, use KERN_CONT
Use KERN_CONT in save_image() for printks, so that anybody won't
try to add a loglevel.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-12-06 16:16:24 +01:00
Nigel Cunningham
8e60c6a134 PM / Hibernate: Shift remaining code from swsusp.c to hibernate.c
Shift the remaining declaration of the variable in_suspend and the
function swsusp_show_speed from swsusp.c to hibernate.c, and delete
swsusp.c.

Signed-off-by: Nigel Cunningham <nigel@tuxonice.net>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-12-06 16:16:07 +01:00
Nigel Cunningham
0414f2ec03 PM / Hibernate: Move swap functions to kernel/power/swap.c.
Move hibernation code's functions for allocating and freeing swap
from swsusp.c to swap.c, which is where you'd expect to find them.

Signed-off-by: Nigel Cunningham <nigel@tuxonice.net>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-12-06 16:15:53 +01:00
Rafael J. Wysocki
64357ed468 Merge branch 'master' into for-linus 2009-12-06 16:06:11 +01:00
Frank Rowand
f5754bfd10 lockstat: Add usage info to Documentation/lockstat.txt
Add usage info to Documentation/lockstat.txt

Signed-off-by: Frank Rowand <frank.rowand@am.sony.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4B05BE7D.30500@am.sony.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-06 13:20:02 +01:00
Frank Rowand
109d71c6dd lockstat: Fix min, max times in /proc/lock_stats
Fix min, max times in /proc/lock_stats

(1) When collecting lock hold and wait times, if the current minimum
    time is zero, it will be replaced by the next time.

(2) When aggregating minimum and maximum lock hold and wait times
    accross cpus, the values are added, instead of selecting the
    minimum and maximum.

Signed-off-by: Frank Rowand <frank.rowand@am.sony.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4B05BBAE.2050005@am.sony.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-06 13:20:00 +01:00
Jean Delvare
be2bf0a2df x86, perf probe: Fix warning in test_get_len()
Fix the following warning:

 arch/x86/tools/test_get_len.c: In function "main":
 arch/x86/tools/test_get_len.c:116: warning: unused variable "c"

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-06 12:53:40 +01:00
Roel Kluin
49966bae84 m68k: parport_mfc3 - Not makes it a bool before the comparison.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2009-12-06 11:18:28 +01:00
Stephen Rothwell
f699b7f351 m68k: don't export static inline functions
These now cause errors due to changes present in linux-next:

(__ksymtab_sorted+0x1258): undefined reference to `dio_dev_driver'
(__ksymtab_sorted+0x4d48): undefined reference to `zorro_dev_driver'

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2009-12-06 11:18:28 +01:00
Krzysztof Helt
8546e3ce6e fbdev: atafb - add palette register check
Add check if palette register number is in correct range
for few drivers which miss it. The regno value comes
indirectly from user space.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2009-12-06 11:18:27 +01:00
John Kacur
87fbaf6aea m68k: Remove the BKL from sys_execve
This seems like a copy-and-paste from code that no-longer needs the BKL
Just remove it.

Signed-off-by: John Kacur <jkacur@redhat.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2009-12-06 11:18:26 +01:00
Tim Abbott
7c5fd5619d m68k: Cleanup linker scripts using new linker script macros.
Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Tested-by: Andreas Schwab <schwab@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2009-12-06 11:18:25 +01:00
Tim Abbott
5cdef24b2a m68k: Make thread_info.h usable from assembly.
[Geert] <asm/thread_info_mm.h> pulls in <asm/current.h>, which contains C only.
So the include must be moved inside #ifndef __ASSEMBLY__.

Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: linux-m68k@lists.linux-m68k.org
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2009-12-06 11:18:24 +01:00
Greg Ungerer
f60a557267 m68knommu: define arch_has_single_step() and friends
Towards adding CONFIG_UTRACE support for non-mmu m68k add
arch_has_single_step, and its support functions user_enable_single_step()
and user_disable_single_step().
[Geert] m68k conflict resolution from linux-next

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2009-12-06 11:18:23 +01:00
Julia Lawall
59b4caeb79 perf tools: Correct size computation in tracepoint_id_to_path()
The size argument to zalloc should be the size of desired
structure, not the pointer to it.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@expression@
expression *x;
@@

x =
 <+...
-sizeof(x)
+sizeof(*x)
...+>// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <Pine.LNX.4.64.0912061016120.20858@ask.diku.dk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-06 10:21:59 +01:00
Jens Axboe
bb729bc98c cfq-iosched: use call_rcu() instead of doing grace period stall on queue exit
After the merge of the IO controller patches, booting on my megaraid
box ran much slower. Vivek Goyal traced it down to megaraid discovery
creating tons of devices, each suffering a grace period when they later
kill that queue (if no device is found).

So lets use call_rcu() to batch these deferred frees, instead of taking
the grace period hit for each one.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-12-06 09:54:19 +01:00
J. R. Okajima
ddbf2e8366 slab, kmemleak: pass the correct pointer to kmemleak_erase()
In ____cache_alloc(), the variable 'ac' may be changed after
cache_alloc_refill() and the following kmemleak_erase() may get an incorrect
pointer. Update 'ac' after cache_alloc_refill() unconditionally.

See the following URL for the discussion of this patch:

 http://marc.info/?l=linux-kernel&m=125873373124187&w=2

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-12-06 10:24:03 +02:00
Shaun Patterson
8055039c2a x86: Fix typo in arch/x86/mm/kmmio.c
Signed-off-by: Shaun Patterson <shaunpatterson@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: pq@iki.fi
LKML-Reference: <1260027694.10074.170.camel@linux-4lgc.site>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-06 09:23:40 +01:00
J. R. Okajima
f3d8b53a3a slab, kmemleak: stop calling kmemleak_erase() unconditionally
When the gotten object is NULL (probably due to ENOMEM), kmemleak_erase() is
unnecessary here, It just sets NULL to where already is NULL.  Add a condition.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-12-06 10:23:05 +02:00
Tim Blechmann
8e15b79cf4 SLAB: Fix unlikely() annotation in __cache_alloc_node()
Branch profiling on my nehalem machine showed 99% incorrect branch hints:

   28459  7678524  99 __cache_alloc_node             slab.c               3551

Discussion on lkml [1] led to the solution to remove this hint.

[1] http://patchwork.kernel.org/patch/63517/

Signed-off-by: Tim Blechmann <tim@klingt.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-12-06 10:21:21 +02:00
Frederic Weisbecker
af2d8289f5 x86: Fixup wrong irq frame link in stacktraces
When we enter in irq, two things can happen to preserve the link
to the previous frame pointer:

- If we were in an irq already, we don't switch to the irq stack
  as we are inside. We just need to save the previous frame
  pointer and to link the new one to the previous.

- Otherwise we need another level of indirection. We enter the irq with
  the previous stack. We save the previous bp inside and make bp
  pointing to its saved address. Then we switch to the irq stack and
  push bp another time but to the new stack. This makes two levels to
  dereference instead of one.

In the second case, the current stacktrace code omits the second level
and loses the frame pointer accuracy. The stack that follows will then
be considered as unreliable.

Handling that makes the perf callchain happier.
Before:

43.94%  [k] _raw_read_lock
            |
            --- _read_lock
               |
               |--60.53%-- send_sigio
               |          __kill_fasync
               |          kill_fasync
               |          evdev_pass_event
               |          evdev_event
               |          input_pass_event
               |          input_handle_event
               |          input_event
               |          synaptics_process_byte
               |          psmouse_handle_byte
               |          psmouse_interrupt
               |          serio_interrupt
               |          i8042_interrupt
               |          handle_IRQ_event
               |          handle_edge_irq
               |          handle_irq
               |          __irqentry_text_start
               |          ret_from_intr
               |          |
               |          |--30.43%-- __select
               |          |
               |          |--17.39%-- 0x454f15
               |          |
               |          |--13.04%-- __read
               |          |
               |          |--13.04%-- vread_hpet
               |          |
               |          |--13.04%-- _xcb_lock_io
               |          |
               |           --13.04%-- 0x7f630878ce8

After:

    50.00%  [k] _raw_read_lock
            |
            --- _read_lock
               |
               |--98.97%-- send_sigio
               |          __kill_fasync
               |          kill_fasync
               |          evdev_pass_event
               |          evdev_event
               |          input_pass_event
               |          input_handle_event
               |          input_event
               |          |
               |          |--96.88%-- synaptics_process_byte
               |          |          psmouse_handle_byte
               |          |          psmouse_interrupt
               |          |          serio_interrupt
               |          |          i8042_interrupt
               |          |          handle_IRQ_event
               |          |          handle_edge_irq
               |          |          handle_irq
               |          |          __irqentry_text_start
               |          |          ret_from_intr
               |          |          |
               |          |          |--39.78%-- __const_udelay
               |          |          |          |
               |          |          |          |--91.89%-- ath5k_hw_register_timeout
               |          |          |          |          ath5k_hw_noise_floor_calibration
               |          |          |          |          ath5k_hw_reset
               |          |          |          |          ath5k_reset
               |          |          |          |          ath5k_config
               |          |          |          |          ieee80211_hw_config
               |          |          |          |          |
               |          |          |          |          |--88.24%-- ieee80211_scan_work
               |          |          |          |          |          worker_thread
               |          |          |          |          |          kthread
               |          |          |          |          |          child_rip
               |          |          |          |          |
               |          |          |          |           --11.76%-- ieee80211_scan_completed
               |          |          |          |                     ieee80211_scan_work
               |          |          |          |                     worker_thread
               |          |          |          |                     kthread
               |          |          |          |                     child_rip
               |          |          |          |
               |          |          |           --8.11%-- ath5k_hw_noise_floor_calibration
               |          |          |                     ath5k_hw_reset
               |          |          |                     ath5k_reset
               |          |          |                     ath5k_config

Note: This does not only affect perf events but also x86-64
stacktraces. They were considered as unreliable once we quit
the irq stack frame.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
2009-12-06 08:27:24 +01:00
Frederic Weisbecker
b625b3b3b7 x86: Fixup wrong debug exception frame link in stacktraces
While dumping a stacktrace, the end of the exception stack won't link
the frame pointer to the previous stack.

The interrupted stack will then be considered as unreliable and ignored
by perf, as the frame pointer is unreliable itself.

This happens because we overwrite the frame pointer that links to the
interrupted frame with the address of the exception stack. This is
done in order to reserve space inside.
But rbp has been chosen here only because it is not a scratch register,
so that the address of the exception stack remains in rbp after calling
do_debug(), we can then release the exception stack space without the
need to retrieve its address again.

But we can pick another non-scratch register to do that, so that we
preserve the link to the interrupted stack frame in the stacktraces.

Just randomly choose r12. Every registers are saved just before and
restored just after calling do_debug(). And r12 is not used in the
middle, which makes it a perfect candidate.

Example: perf record -g -a -c 1 -f -e mem:$(tasklist_lock_addr):rw

Before:
    44.18%  [k] _raw_read_lock
            |
            |
            ---  |--6.31%-- waitid
                 |
                 |--4.26%-- writev
                 |
                 |--3.63%-- __select
                 |
                 |--3.15%-- __waitpid
                 |          |
                 |          |--28.57%-- 0x8b52e00000139f
                 |          |
                 |          |--28.57%-- 0x8b52e0000013c6
                 |          |
                 |          |--14.29%-- 0x7fde786dc000
                 |          |
                 |          |--14.29%-- 0x62696c2f7273752f
                 |          |
                 |           --14.29%-- 0x1ea9df800000000
                 |
                 |--3.00%-- __poll

After:

    43.94%  [k] _raw_read_lock
            |
            --- _read_lock
               |
               |--60.53%-- send_sigio
               |          __kill_fasync
               |          kill_fasync
               |          evdev_pass_event
               |          evdev_event
               |          input_pass_event
               |          input_handle_event
               |          input_event
               |          synaptics_process_byte
               |          psmouse_handle_byte
               |          psmouse_interrupt
               |          serio_interrupt
               |          i8042_interrupt
               |          handle_IRQ_event
               |          handle_edge_irq
               |          handle_irq
               |          __irqentry_text_start
               |          ret_from_intr
               |          |
               |          |--30.43%-- __select
               |          |
               |          |--17.39%-- 0x454f15
               |          |
               |          |--13.04%-- __read
               |          |
               |          |--13.04%-- vread_hpet
               |          |
               |          |--13.04%-- _xcb_lock_io
               |          |
               |           --13.04%-- 0x7f630878ce87

Note: it does not only affect perf events but also other stacktraces in
x86-64. They were considered as unreliable once we quit the debug
stack frame.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
2009-12-06 08:27:22 +01:00
Frederic Weisbecker
7f33f9c5cc x86/perf: Exclude the debug stack from the callchains
Dumping the callchains from breakpoint events with perf gives strange
results:

3.75%             perf  [kernel]           [k] _raw_read_unlock
                       |
                       --- _raw_read_unlock
                           perf_callchain
                           perf_prepare_sample
                           __perf_event_overflow
                           perf_swevent_overflow
                           perf_swevent_add
                           perf_bp_event
                           hw_breakpoint_exceptions_notify
                           notifier_call_chain
                           __atomic_notifier_call_chain
                           atomic_notifier_call_chain
                           notify_die
                           do_debug
                           debug
                           munmap

We are infected with all the debug stack. Like the nmi stack, the debug
stack is undesired as it is part of the profiling path, not helpful for
the user.

Ignore it.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
2009-12-06 08:27:21 +01:00
Frederic Weisbecker
c0dfb2feb6 perf: Remove the "event" callback from perf events
As it is not used anymore and has been superseded by overflow_handler.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
2009-12-06 08:27:20 +01:00
Frederic Weisbecker
b326e9560a hw-breakpoints: Use overflow handler instead of the event callback
struct perf_event::event callback was called when a breakpoint
triggers. But this is a rather opaque callback, pretty
tied-only to the breakpoint API and not really integrated into perf
as it triggers even when we don't overflow.

We prefer to use overflow_handler() as it fits into the perf events
rules, being called only when we overflow.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
2009-12-06 08:27:18 +01:00
Frederic Weisbecker
2f0993e0fb hw-breakpoints: Drop callback and task parameters from modify helper
Drop the callback and task parameters from modify_user_hw_breakpoint().
For now we have no user that need to modify a breakpoint to the point
of changing its handler or its task context.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
2009-12-06 08:27:17 +01:00