Commit graph

253 commits

Author SHA1 Message Date
Srivatsa S. Bhat
76902e3d9c x86, oprofile, nmi: Fix CPU hotplug callback registration
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:

	get_online_cpus();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	register_cpu_notifier(&foobar_cpu_notifier);

	put_online_cpus();

This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).

Instead, the correct and race-free way of performing the callback
registration is:

	cpu_notifier_register_begin();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	/* Note the use of the double underscored version of the API */
	__register_cpu_notifier(&foobar_cpu_notifier);

	cpu_notifier_register_done();

Fix the oprofile code in x86 by using this latter form of callback
registration. But retain the calls to get/put_online_cpus(), since they are
used in other places as well, to protect the variables 'nmi_enabled' and
'ctr_running'. Strictly speaking, this is not necessary since
cpu_notifier_register_begin/done() provide a stronger synchronization
with CPU hotplug than get/put_online_cpus(). However, let's retain the
calls to get/put_online_cpus() to be consistent with the other call-sites.

By nesting get/put_online_cpus() *inside* cpu_notifier_register_begin/done(),
we avoid the ABBA deadlock possibility mentioned above.

Cc: Robert Richter <rric@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-20 13:43:43 +01:00
Peter Zijlstra
0a196848ca perf: Fix arch_perf_out_copy_user default
The arch_perf_output_copy_user() default of
__copy_from_user_inatomic() returns bytes not copied, while all other
argument functions given DEFINE_OUTPUT_COPY() return bytes copied.

Since copy_from_user_nmi() is the odd duck out by returning bytes
copied where all other *copy_{to,from}* functions return bytes not
copied, change it over and ammend DEFINE_OUTPUT_COPY() to expect bytes
not copied.

Oddly enough DEFINE_OUTPUT_COPY() already returned bytes not copied
while expecting its worker functions to return bytes copied.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: will.deacon@arm.com
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20131030201622.GR16117@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 12:34:25 +01:00
Al Viro
6af4ea0ba7 oprofilefs_create_...() do not need superblock argument
same story as with oprofilefs_mkdir()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-03 22:52:48 -04:00
Al Viro
ecde28237e oprofilefs_mkdir() doesn't need superblock argument
it's always equal to ->d_sb of the second argument (parent dentry),
due to either being literally that, or ->d_sb of parent's parent.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-03 22:52:47 -04:00
Al Viro
ef7bca1456 oprofile: don't bother with passing superblock to ->create_files()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-03 22:52:46 -04:00
Dan Carpenter
4400910508 oprofile, x86: Fix wrapping bug in op_x86_get_ctrl()
The "event" variable is a u16 so the shift will always wrap to zero
making the line a no-op.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: <stable@vger.kernel.org> v2.6.32..
Signed-off-by: Robert Richter <robert.richter@amd.com>
2012-10-15 14:38:24 +02:00
Robert Richter
b1dc3c4820 perf/x86/amd: Unify AMD's generic and family 15h pmus
There is no need for keeping separate pmu structs. We can enable
amd_{get,put}_event_constraints() functions also for family 15h event.

The advantage is that there is only a single pmu struct for all AMD
cpus. This patch introduces functions to setup the pmu to enabe core
performance counters or counter constraints.

Also, cpuid checks are used instead of family checks where
possible. Thus, it enables the code independently of cpu families if
the feature flag is set.

Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1340217996-2254-4-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-05 21:19:41 +02:00
H. Peter Anvin
6bd330083e x86: Factor out TIF_IA32 from 32-bit address space
Factor out IA32 (compatibility instruction set) from 32-bit address
space in the thread_info flags; this is a precondition patch for x32
support.

Originally-by: H. J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-4pr1xnnksprt7t0h3w5fw4rv@git.kernel.org
2012-02-20 12:48:46 -08:00
Ingo Molnar
c23205c848 Merge branch 'core' of git://amd64.org/linux/rric into perf/core 2011-11-15 11:05:18 +01:00
Robert Richter
de346b6949 Merge branch 'perf/core' into oprofile/master
Merge reason: Resolve conflicts with Don's NMI rework:

    commit 9c48f1c629
    Author: Don Zickus <dzickus@redhat.com>
    Date:   Fri Sep 30 15:06:21 2011 -0400
    x86, nmi: Wire up NMI handlers to new routines

Conflicts:
	arch/x86/oprofile/nmi_timer_int.c

Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-11-08 15:52:15 +01:00
Robert Richter
dcfce4a095 oprofile, x86: Reimplement nmi timer mode using perf event
The legacy x86 nmi watchdog code was removed with the implementation
of the perf based nmi watchdog. This broke Oprofile's nmi timer
mode. To run nmi timer mode we relied on a continuous ticking nmi
source which the nmi watchdog provided. The nmi tick was no longer
available and current watchdog can not be used anymore since it runs
with very long periods in the range of seconds. This patch
reimplements the nmi timer mode using a perf counter nmi source.

V2:
* removing pr_info()
* fix undefined reference to `__udivdi3' for 32 bit build
* fix section mismatch of .cpuinit.data:nmi_timer_cpu_nb
* removed nmi timer setup in arch/x86
* implemented function stubs for op_nmi_init/exit()
* made code more readable in oprofile_init()

V3:
* fix architectural initialization in oprofile_init()
* fix CONFIG_OPROFILE_NMI_TIMER dependencies

Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-11-04 16:27:18 +01:00
Robert Richter
159a80b214 oprofile, x86: Add kernel parameter oprofile.cpu_type=timer
We need this to better test x86 NMI timer mode. Otherwise it is very
hard to setup systems with NMI timer enabled, but we have this e.g. in
virtual machine environments.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-11-04 15:04:34 +01:00
Robert Richter
97f7f8189f oprofile, x86: Fix crash when unloading module (nmi timer mode)
If oprofile uses the nmi timer interrupt there is a crash while
unloading the module. The bug can be triggered with oprofile build as
module and kernel parameter nolapic set. This patch fixes this.

oprofile: using NMI timer interrupt.
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: [<ffffffff8123c226>] unregister_syscore_ops+0x41/0x58
PGD 42dbca067 PUD 41da6a067 PMD 0
Oops: 0002 [#1] PREEMPT SMP
CPU 5
Modules linked in: oprofile(-) [last unloaded: oprofile]

Pid: 2518, comm: modprobe Not tainted 3.1.0-rc7-00019-gb2fb49d #19 Advanced Micro Device Anaheim/Anaheim
RIP: 0010:[<ffffffff8123c226>]  [<ffffffff8123c226>] unregister_syscore_ops+0x41/0x58
RSP: 0018:ffff88041ef71e98  EFLAGS: 00010296
RAX: 0000000000000000 RBX: ffffffffa0017100 RCX: dead000000200200
RDX: 0000000000000000 RSI: dead000000100100 RDI: ffffffff8178c620
RBP: ffff88041ef71ea8 R08: 0000000000000001 R09: 0000000000000082
R10: 0000000000000000 R11: ffff88041ef71de8 R12: 0000000000000080
R13: fffffffffffffff5 R14: 0000000000000001 R15: 0000000000610210
FS:  00007fc902f20700(0000) GS:ffff88042fd40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000008 CR3: 000000041cdb6000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process modprobe (pid: 2518, threadinfo ffff88041ef70000, task ffff88041d348040)
Stack:
 ffff88041ef71eb8 ffffffffa0017790 ffff88041ef71eb8 ffffffffa0013532
 ffff88041ef71ec8 ffffffffa00132d6 ffff88041ef71ed8 ffffffffa00159b2
 ffff88041ef71f78 ffffffff81073115 656c69666f72706f 0000000000610200
Call Trace:
 [<ffffffffa0013532>] op_nmi_exit+0x15/0x17 [oprofile]
 [<ffffffffa00132d6>] oprofile_arch_exit+0xe/0x10 [oprofile]
 [<ffffffffa00159b2>] oprofile_exit+0x1e/0x20 [oprofile]
 [<ffffffff81073115>] sys_delete_module+0x1c3/0x22f
 [<ffffffff811bf09e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
 [<ffffffff8148070b>] system_call_fastpath+0x16/0x1b
Code: 20 c6 78 81 e8 c5 cc 23 00 48 8b 13 48 8b 43 08 48 be 00 01 10 00 00 00 ad de 48 b9 00 02 20 00 00 00 ad de 48 c7 c7 20 c6 78 81
 89 42 08 48 89 10 48 89 33 48 89 4b 08 e8 a6 c0 23 00 5a 5b
RIP  [<ffffffff8123c226>] unregister_syscore_ops+0x41/0x58
 RSP <ffff88041ef71e98>
CR2: 0000000000000008
---[ end trace 43a541a52956b7b0 ]---

CC: stable@kernel.org # 2.6.37+
Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-11-04 15:04:33 +01:00
Linus Torvalds
7115e3fcf4 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (121 commits)
  perf symbols: Increase symbol KSYM_NAME_LEN size
  perf hists browser: Refuse 'a' hotkey on non symbolic views
  perf ui browser: Use libslang to read keys
  perf tools: Fix tracing info recording
  perf hists browser: Elide DSO column when it is set to just one DSO, ditto for threads
  perf hists: Don't consider filtered entries when calculating column widths
  perf hists: Don't decay total_period for filtered entries
  perf hists browser: Honour symbol_conf.show_{nr_samples,total_period}
  perf hists browser: Do not exit on tab key with single event
  perf annotate browser: Don't change selection line when returning from callq
  perf tools: handle endianness of feature bitmap
  perf tools: Add prelink suggestion to dso update message
  perf script: Fix unknown feature comment
  perf hists browser: Apply the dso and thread filters when merging new batches
  perf hists: Move the dso and thread filters from hist_browser
  perf ui browser: Honour the xterm colors
  perf top tui: Give color hints just on the percentage, like on --stdio
  perf ui browser: Make the colors configurable and change the defaults
  perf tui: Remove unneeded call to newtCls on startup
  perf hists: Don't format the percentage on hist_entry__snprintf
  ...

Fix up conflicts in arch/x86/kernel/kprobes.c manually.

Ingo's tree did the insane "add volatile to const array", which just
doesn't make sense ("volatile const"?).  But we could remove the const
*and* make the array volatile to make doubly sure that gcc doesn't
optimize it away..

Also fix up kernel/trace/ring_buffer.c non-data-conflicts manually: the
reader_lock has been turned into a raw lock by the core locking merge,
and there was a new user of it introduced in this perf core merge.  Make
sure that new use also uses the raw accessor functions.
2011-10-26 17:03:38 +02:00
Robert Richter
b716916679 perf, x86: Implement IBS initialization
This patch implements IBS feature detection and initialzation. The
code is shared between perf and oprofile. If IBS is available on the
system for perf, a pmu is setup.

Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1316597423-25723-3-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-10-10 06:57:16 +02:00
Robert Richter
ee5789dbcc perf, x86: Share IBS macros between perf and oprofile
Moving IBS macros from oprofile to <asm/perf_event.h> to make it
available to perf. No additional changes.

Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1316597423-25723-2-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-10-10 06:57:11 +02:00
Don Zickus
9c48f1c629 x86, nmi: Wire up NMI handlers to new routines
Just convert all the files that have an nmi handler to the new routines.
Most of it is straight forward conversion.  A couple of places needed some
tweaking like kgdb which separates the debug notifier from the nmi handler
and mce removes a call to notify_die.

[Thanks to Ying for finding out the history behind that mce call

https://lkml.org/lkml/2010/5/27/114

And Boris responding that he would like to remove that call because of it

https://lkml.org/lkml/2011/9/21/163]

The things that get converted are the registeration/unregistration routines
and the nmi handler itself has its args changed along with code removal
to check which list it is on (most are on one NMI list except for kgdb
which has both an NMI routine and an NMI Unknown routine).

Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Corey Minyard <minyard@acm.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Corey Minyard <minyard@acm.org>
Cc: Jack Steiner <steiner@sgi.com>
Link: http://lkml.kernel.org/r/1317409584-23662-4-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-10-10 06:56:57 +02:00
Thomas Gleixner
2d21a29fb6 locking, oprofile: Annotate oprofilefs lock as raw
The oprofilefs_lock can be taken in atomic context (in profiling
interrupts) and therefore cannot cannot be preempted on -rt -
annotate it.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-09-13 11:12:05 +02:00
Robert Richter
298557db42 oprofile, x86: Fix overflow and warning (commit 1d12d35)
Following fixes for:

 1d12d35 oprofile, x86: Convert memory allocation to static array

Fix potential buffer overflow.

Fix the following warning:

 arch/x86/oprofile/op_model_ppro.c: In function ‘ppro_check_ctrs’:
 arch/x86/oprofile/op_model_ppro.c:143: warning: label ‘out’ defined but not used

Cc: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-08-16 23:51:00 +02:00
Maarten Lankhorst
1d12d35284 oprofile, x86: Convert memory allocation to static array
On -rt, allocators don't work from atomic context any more,
and the maximum size of the array is known at compile time.

Call trace on a -rt kernel:

oprofile: using NMI interrupt.
BUG: sleeping function called from invalid context at kernel/rtmutex.c:645
in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: kworker/0:1
Pid: 0, comm: kworker/0:1 Tainted: G         C  3.0.0-rt3-patser+ #39
Call Trace:
 <IRQ>  [<ffffffff8103fc0a>] __might_sleep+0xca/0xf0
 [<ffffffff8160d424>] rt_spin_lock+0x24/0x40
 [<ffffffff811476c7>] __kmalloc+0xc7/0x370
 [<ffffffffa0275c85>] ? ppro_setup_ctrs+0x215/0x260 [oprofile]
 [<ffffffffa0273de0>] ? oprofile_cpu_notifier+0x60/0x60 [oprofile]
 [<ffffffffa0275c85>] ppro_setup_ctrs+0x215/0x260 [oprofile]
 [<ffffffffa0273de0>] ? oprofile_cpu_notifier+0x60/0x60 [oprofile]
 [<ffffffffa0273de0>] ? oprofile_cpu_notifier+0x60/0x60 [oprofile]
 [<ffffffffa0273ea4>] nmi_cpu_setup+0xc4/0x110 [oprofile]
 [<ffffffff81094455>] generic_smp_call_function_interrupt+0x95/0x190
 [<ffffffff8101df77>] smp_call_function_interrupt+0x27/0x40
 [<ffffffff81615093>] call_function_interrupt+0x13/0x20
 <EOI>  [<ffffffff8131d0c4>] ? plist_check_head+0x54/0xc0
 [<ffffffff81371fe8>] ? intel_idle+0xc8/0x120
 [<ffffffff81371fc7>] ? intel_idle+0xa7/0x120
 [<ffffffff814a57b0>] cpuidle_idle_call+0xb0/0x230
 [<ffffffff810011db>] cpu_idle+0x8b/0xe0
 [<ffffffff815fc82f>] start_secondary+0x1d3/0x1d8

Signed-off-by: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-08-01 22:54:19 +02:00
Robert Richter
1ac2e6ca44 x86, perf: Make copy_from_user_nmi() a library function
copy_from_user_nmi() is used in oprofile and perf. Moving it to other
library functions like copy_from_user(). As this is x86 code for 32
and 64 bits, create a new file usercopy.c for unified code.

Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110607172413.GJ20052@erda.amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 20:41:57 +02:00
Robert Richter
a0e3e70243 oprofile, x86: Fix nmi-unsafe callgraph support
Current oprofile's x86 callgraph support may trigger page faults
throwing the BUG_ON(in_nmi()) message below. This patch fixes this by
using the same nmi-safe copy-from-user code as in perf.

------------[ cut here ]------------
kernel BUG at .../arch/x86/kernel/traps.c:436!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/devices/pci0000:00/0000:00:0a.0/0000:07:00.0/0000:08:04.0/net/eth0/broadcast
CPU 5
Modules linked in:

Pid: 8611, comm: opcontrol Not tainted 2.6.39-00007-gfe47ae7 #1 Advanced Micro Device Anaheim/Anaheim
RIP: 0010:[<ffffffff813e8e35>]  [<ffffffff813e8e35>] do_nmi+0x22/0x1ee
RSP: 0000:ffff88042fd47f28  EFLAGS: 00010002
RAX: ffff88042c0a7fd8 RBX: 0000000000000001 RCX: 00000000c0000101
RDX: 00000000ffff8804 RSI: ffffffffffffffff RDI: ffff88042fd47f58
RBP: ffff88042fd47f48 R08: 0000000000000004 R09: 0000000000001484
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88042fd47f58
R13: 0000000000000000 R14: ffff88042fd47d98 R15: 0000000000000020
FS:  00007fca25e56700(0000) GS:ffff88042fd40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000074 CR3: 000000042d28b000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process opcontrol (pid: 8611, threadinfo ffff88042c0a6000, task ffff88042c532310)
Stack:
 0000000000000000 0000000000000001 ffff88042c0a7fd8 0000000000000000
 ffff88042fd47de8 ffffffff813e897a 0000000000000020 ffff88042fd47d98
 0000000000000000 ffff88042c0a7fd8 ffff88042fd47de8 0000000000000074
Call Trace:
 <NMI>
 [<ffffffff813e897a>] nmi+0x1a/0x20
 [<ffffffff813f08ab>] ? bad_to_user+0x25/0x771
 <<EOE>>
Code: ff 59 5b 41 5c 41 5d c9 c3 55 65 48 8b 04 25 88 b5 00 00 48 89 e5 41 55 41 54 49 89 fc 53 48 83 ec 08 f6 80 47 e0 ff ff 04 74 04 <0f> 0b eb fe 81 80 44 e0 ff ff 00 00 01 04 65 ff 04 25 c4 0f 01
RIP  [<ffffffff813e8e35>] do_nmi+0x22/0x1ee
 RSP <ffff88042fd47f28>
---[ end trace ed6752185092104b ]---
Kernel panic - not syncing: Fatal exception in interrupt
Pid: 8611, comm: opcontrol Tainted: G      D     2.6.39-00007-gfe47ae7 #1
Call Trace:
 <NMI>  [<ffffffff813e5e0a>] panic+0x8c/0x188
 [<ffffffff813e915c>] oops_end+0x81/0x8e
 [<ffffffff8100403d>] die+0x55/0x5e
 [<ffffffff813e8c45>] do_trap+0x11c/0x12b
 [<ffffffff810023c8>] do_invalid_op+0x91/0x9a
 [<ffffffff813e8e35>] ? do_nmi+0x22/0x1ee
 [<ffffffff8131e6fa>] ? oprofile_add_sample+0x83/0x95
 [<ffffffff81321670>] ? op_amd_check_ctrs+0x4f/0x2cf
 [<ffffffff813ee4d5>] invalid_op+0x15/0x20
 [<ffffffff813e8e35>] ? do_nmi+0x22/0x1ee
 [<ffffffff813e8e7a>] ? do_nmi+0x67/0x1ee
 [<ffffffff813e897a>] nmi+0x1a/0x20
 [<ffffffff813f08ab>] ? bad_to_user+0x25/0x771
 <<EOE>>

Cc: John Lumby <johnlumby@hotmail.com>
Cc: Maynard Johnson <maynardj@us.ibm.com>
Cc: <stable@kernel.org> # .37+
Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-06-15 14:31:33 +02:00
Robert Richter
8fe7e94eb7 oprofile, x86: Fix race in nmi handler while starting counters
In some rare cases, nmis are generated immediately after the nmi
handler of the cpu was started. This causes the counter not to be
enabled. Before enabling the nmi handlers we need to set variable
ctr_running first and make sure its value is written to memory.

Also, the patch makes all existing barriers a memory barrier instead
of a compiler barrier only.

Reported-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: <stable@kernel.org> # .35+
Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-06-15 14:31:29 +02:00
Ingo Molnar
86dd7909c2 Merge branch 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/urgent 2011-06-08 15:49:03 +02:00
Robert Richter
cbf74cea07 oprofile, x86: Add comments to IBS LVT offset initialization
Adding a comment in the code as IBS LVT setup is not obvious at all ...

Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-05-30 16:36:54 +02:00
Ingo Molnar
b1d2dc3c06 Merge branch 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/urgent 2011-05-27 14:08:09 +02:00
Robert Richter
3d2606f429 oprofile, x86: Enable preemption during pci device setup in IBS init
IBS initialization is a mix of per-core register access and per-node
pci device setup. Register access should be pinned to the cpu, but pci
setup must run with preemption enabled.

This patch better separates the code into non-/preemptible sections
and fixes sleeping with preemption disabled. See bug message below.

Fixes also freeing the eilvt entry by introducing put_eilvt().

BUG: sleeping function called from invalid context at mm/slub.c:824
in_atomic(): 1, irqs_disabled(): 0, pid: 32357, name: modprobe
INFO: lockdep is turned off.
Pid: 32357, comm: modprobe Not tainted 2.6.39-rc7+ #14
Call Trace:
 [<ffffffff8104bdc8>] __might_sleep+0x112/0x117
 [<ffffffff81129693>] kmem_cache_alloc_trace+0x4b/0xe7
 [<ffffffff81278f14>] kzalloc.constprop.0+0x29/0x2b
 [<ffffffff81278f4c>] pci_get_subsys+0x36/0x78
 [<ffffffff81022689>] ? setup_APIC_eilvt+0xfb/0x139
 [<ffffffff81278fa4>] pci_get_device+0x16/0x18
 [<ffffffffa06c8b5d>] op_amd_init+0xd3/0x211 [oprofile]
 [<ffffffffa064d000>] ? 0xffffffffa064cfff
 [<ffffffffa064d298>] op_nmi_init+0x21e/0x26a [oprofile]
 [<ffffffffa064d062>] oprofile_arch_init+0xe/0x26 [oprofile]
 [<ffffffffa064d010>] oprofile_init+0x10/0x42 [oprofile]
 [<ffffffff81002099>] do_one_initcall+0x7f/0x13a
 [<ffffffff81096524>] sys_init_module+0x132/0x281
 [<ffffffff814cc682>] system_call_fastpath+0x16/0x1b

Reported-by: Dave Jones <davej@redhat.com>
Cc: <stable@kernel.org>         [2.6.37.x]
Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-05-20 17:11:10 +02:00
Richard Weinberger
449a66fd1f x86: Remove warning and warning_symbol from struct stacktrace_ops
Both warning and warning_symbol are nowhere used.
Let's get rid of them.

Signed-off-by: Richard Weinberger <richard@nod.at>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Soeren Sandmann Pedersen <ssp@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: x86 <x86@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Link: http://lkml.kernel.org/r/1305205872-10321-2-git-send-email-richard@nod.at
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2011-05-12 15:31:28 +02:00
Ingo Molnar
1dfd7b494b Merge branch 'core' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/urgent 2011-03-29 09:32:28 +02:00
Andi Kleen
914a76ca5e oprofile, x86: Allow setting EDGE/INV/CMASK for counter events
For some performance events it's useful to set the EDGE and INV
bits and the CMASK mask in the counter control register. The list
of predefined events Intel releases for each CPU has some events which
require these settings to get more "natural" to use higher level events.

oprofile currently doesn't allow this.

This patch adds new extra configuration fields for them, so that
they can be specified in oprofilefs.

An updated oprofile daemon can then make use of this to set them.

v2: Write back masked extra value to variable.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2011-03-24 18:45:44 +01:00
Rafael J. Wysocki
f3c6ea1b06 x86: Use syscore_ops instead of sysdev classes and sysdevs
Some subsystems in the x86 tree need to carry out suspend/resume and
shutdown operations with one CPU on-line and interrupts disabled and
they define sysdev classes and sysdevs or sysdev drivers for this
purpose.  This leads to unnecessarily complicated code and excessive
memory usage, so switch them to using struct syscore_ops objects for
this purpose instead.

Generally, there are three categories of subsystems that use
sysdevs for implementing PM operations: (1) subsystems whose
suspend/resume callbacks ignore their arguments entirely (the
majority), (2) subsystems whose suspend/resume callbacks use their
struct sys_device argument, but don't really need to do that,
because they can be implemented differently in an arguably simpler
way (io_apic.c), and (3) subsystems whose suspend/resume callbacks
use their struct sys_device argument, but the value of that argument
is always the same and could be ignored (microcode_core.c).  In all
of these cases the subsystems in question may be readily converted to
using struct syscore_ops objects for power management and shutdown.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
2011-03-23 22:15:54 +01:00
Linus Torvalds
f2e1fbb5f2 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Flush TLB if PGD entry is changed in i386 PAE mode
  x86, dumpstack: Correct stack dump info when frame pointer is available
  x86: Clean up csum-copy_64.S a bit
  x86: Fix common misspellings
  x86: Fix misspelling and align params
  x86: Use PentiumPro-optimized partial_csum() on VIA C7
2011-03-18 10:45:21 -07:00
Namhyung Kim
e8e999cf3c x86, dumpstack: Correct stack dump info when frame pointer is available
Current stack dump code scans entire stack and check each entry
contains a pointer to kernel code. If CONFIG_FRAME_POINTER=y it
could mark whether the pointer is valid or not based on value of
the frame pointer. Invalid entries could be preceded by '?' sign.

However this was not going to happen because scan start point
was always higher than the frame pointer so that they could not
meet.

Commit 9c0729dc80 ("x86: Eliminate bp argument from the stack
tracing routines") delayed bp acquisition point, so the bp was
read in lower frame, thus all of the entries were marked
invalid.

This patch fixes this by reverting above commit while retaining
stack_frame() helper as suggested by Frederic Weisbecker.

End result looks like below:

before:

 [    3.508329] Call Trace:
 [    3.508551]  [<ffffffff814f35c9>] ? panic+0x91/0x199
 [    3.508662]  [<ffffffff814f3739>] ? printk+0x68/0x6a
 [    3.508770]  [<ffffffff81a981b2>] ? mount_block_root+0x257/0x26e
 [    3.508876]  [<ffffffff81a9821f>] ? mount_root+0x56/0x5a
 [    3.508975]  [<ffffffff81a98393>] ? prepare_namespace+0x170/0x1a9
 [    3.509216]  [<ffffffff81a9772b>] ? kernel_init+0x1d2/0x1e2
 [    3.509335]  [<ffffffff81003894>] ? kernel_thread_helper+0x4/0x10
 [    3.509442]  [<ffffffff814f6880>] ? restore_args+0x0/0x30
 [    3.509542]  [<ffffffff81a97559>] ? kernel_init+0x0/0x1e2
 [    3.509641]  [<ffffffff81003890>] ? kernel_thread_helper+0x0/0x10

after:

 [    3.522991] Call Trace:
 [    3.523351]  [<ffffffff814f35b9>] panic+0x91/0x199
 [    3.523468]  [<ffffffff814f3729>] ? printk+0x68/0x6a
 [    3.523576]  [<ffffffff81a981b2>] mount_block_root+0x257/0x26e
 [    3.523681]  [<ffffffff81a9821f>] mount_root+0x56/0x5a
 [    3.523780]  [<ffffffff81a98393>] prepare_namespace+0x170/0x1a9
 [    3.523885]  [<ffffffff81a9772b>] kernel_init+0x1d2/0x1e2
 [    3.523987]  [<ffffffff81003894>] kernel_thread_helper+0x4/0x10
 [    3.524228]  [<ffffffff814f6880>] ? restore_args+0x0/0x30
 [    3.524345]  [<ffffffff81a97559>] ? kernel_init+0x0/0x1e2
 [    3.524445]  [<ffffffff81003890>] ? kernel_thread_helper+0x0/0x10

 -v5:
   * fix build breakage with oprofile

 -v4:
   * use 0 instead of regs->bp
   * separate out printk changes

 -v3:
   * apply comment from Frederic
   * add a couple of printk fixes

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Soren Sandmann <ssp@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <1300416006-3163-1-git-send-email-namhyung@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18 10:51:42 +01:00
Jesper Juhl
42b16b3fbb Kill off warning: ‘inline’ is not at beginning of declaration
Fix a bunch of
	warning: ‘inline’ is not at beginning of declaration
messages when building a 'make allyesconfig' kernel with -Wextra.

These warnings are trivial to kill, yet rather annoying when building with
-Wextra.
The more we can cut down on pointless crap like this the better (IMHO).

A previous patch to do this for a 'allnoconfig' build has already been
merged. This just takes the cleanup a little further.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-01-19 15:43:08 +01:00
Linus Torvalds
42776163e1 Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (28 commits)
  perf session: Fix infinite loop in __perf_session__process_events
  perf evsel: Support perf_evsel__open(cpus > 1 && threads > 1)
  perf sched: Use PTHREAD_STACK_MIN to avoid pthread_attr_setstacksize() fail
  perf tools: Emit clearer message for sys_perf_event_open ENOENT return
  perf stat: better error message for unsupported events
  perf sched: Fix allocation result check
  perf, x86: P4 PMU - Fix unflagged overflows handling
  dynamic debug: Fix build issue with older gcc
  tracing: Fix TRACE_EVENT power tracepoint creation
  tracing: Fix preempt count leak
  tracepoint: Add __rcu annotation
  tracing: remove duplicate null-pointer check in skb tracepoint
  tracing/trivial: Add missing comma in TRACE_EVENT comment
  tracing: Include module.h in define_trace.h
  x86: Save rbp in pt_regs on irq entry
  x86, dumpstack: Fix unused variable warning
  x86, NMI: Clean-up default_do_nmi()
  x86, NMI: Allow NMI reason io port (0x61) to be processed on any CPU
  x86, NMI: Remove DIE_NMI_IPI
  x86, NMI: Add priorities to handlers
  ...
2011-01-11 11:02:13 -08:00
Ingo Molnar
4385428a47 Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent 2011-01-09 10:42:21 +01:00
Linus Torvalds
72eb6a7914 Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
  gameport: use this_cpu_read instead of lookup
  x86: udelay: Use this_cpu_read to avoid address calculation
  x86: Use this_cpu_inc_return for nmi counter
  x86: Replace uses of current_cpu_data with this_cpu ops
  x86: Use this_cpu_ops to optimize code
  vmstat: User per cpu atomics to avoid interrupt disable / enable
  irq_work: Use per cpu atomics instead of regular atomics
  cpuops: Use cmpxchg for xchg to avoid lock semantics
  x86: this_cpu_cmpxchg and this_cpu_xchg operations
  percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
  percpu,x86: relocate this_cpu_add_return() and friends
  connector: Use this_cpu operations
  xen: Use this_cpu_inc_return
  taskstats: Use this_cpu_ops
  random: Use this_cpu_inc_return
  fs: Use this_cpu_inc_return in buffer.c
  highmem: Use this_cpu_xx_return() operations
  vmstat: Use this_cpu_inc_return for vm statistics
  x86: Support for this_cpu_add, sub, dec, inc_return
  percpu: Generic support for this_cpu_add, sub, dec, inc_return
  ...

Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.
2011-01-07 17:02:58 -08:00
Don Zickus
c410b83077 x86, NMI: Remove DIE_NMI_IPI
With priorities in place and no one really understanding the difference between
DIE_NMI and DIE_NMI_IPI, just remove DIE_NMI_IPI and convert everyone to DIE_NMI.

This also simplifies default_do_nmi() a little bit.  Instead of calling the
die_notifier in both the if and else part, just pull it out and call it before
the if-statement.  This has the side benefit of avoiding a call to the ioport
to see if there is an external NMI sitting around until after the (more frequent)
internal NMIs are dealt with.

Patch-Inspired-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294348732-15030-5-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 15:08:53 +01:00
Don Zickus
166d751479 x86, NMI: Add priorities to handlers
In order to consolidate the NMI die_chain events, we need to setup the priorities
for the die notifiers.

I started by defining a bunch of common priorities that can be used by the
notifier blocks.  Then I modified the notifier blocks to use the newly created
priorities.

Now that the priorities are straightened out, it should be easier to remove the
event DIE_NMI_IPI.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294348732-15030-4-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 15:08:52 +01:00
Linus Torvalds
4e1db5e58a Merge branch 'x86-mce-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-mce-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  apic, amd: Make firmware bug messages more meaningful
  mce, amd: Remove goto in threshold_create_device()
  mce, amd: Add helper functions to setup APIC
  mce, amd: Shorten local variables mci_misc_{hi,lo}
  mce, amd: Implement mce_threshold_block_init() helper function
2011-01-06 11:05:21 -08:00
Ingo Molnar
aef1b9cef7 Merge commit 'v2.6.37' into perf/core
Merge reason: Add the final .37 tree.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-05 14:22:10 +01:00
Robert Richter
c7c25802b3 arch/x86/oprofile/op_model_amd.c: Perform initialisation on a single CPU
Disable preemption in init_ibs(). The function only checks the
ibs capabilities and sets up pci devices (if necessary). It runs
only on one cpu but operates with the local APIC and some MSRs,
thus it is better to disable preemption.

[    7.034377] BUG: using smp_processor_id() in preemptible [00000000] code: modprobe/483
[    7.034385] caller is setup_APIC_eilvt+0x155/0x180
[    7.034389] Pid: 483, comm: modprobe Not tainted 2.6.37-rc1-20101110+ #1
[    7.034392] Call Trace:
[    7.034400]  [<ffffffff812a2b72>] debug_smp_processor_id+0xd2/0xf0
[    7.034404]  [<ffffffff8101e985>] setup_APIC_eilvt+0x155/0x180
[ ... ]

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=22812

Reported-by: <atswartz@gmail.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: oprofile-list@lists.sourceforge.net <oprofile-list@lists.sourceforge.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@kernel.org>         [2.6.37.x]
LKML-Reference: <20110103111514.GM4739@erda.amd.com>
[ small cleanups ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-03 13:01:40 +01:00
Tejun Heo
7b543a5334 x86: Replace uses of current_cpu_data with this_cpu ops
Replace all uses of current_cpu_data with this_cpu operations on the
per cpu structure cpu_info.  The scala accesses are replaced with the
matching this_cpu ops which results in smaller and more efficient
code.

In the long run, it might be a good idea to remove cpu_data() macro
too and use per_cpu macro directly.

tj: updated description

Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-30 12:22:03 +01:00
Tejun Heo
0a3aee0da4 x86: Use this_cpu_ops to optimize code
Go through x86 code and replace __get_cpu_var and get_cpu_var
instances that refer to a scalar and are not used for address
determinations.

Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-30 12:20:28 +01:00
Ingo Molnar
56f4c40034 Merge branch 'core' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/core 2010-12-30 11:26:45 +01:00
Don Zickus
4a7863cc2e x86, nmi_watchdog: Remove ARCH_HAS_NMI_WATCHDOG and rely on CONFIG_HARDLOCKUP_DETECTOR
The x86 arch has shifted its use of the nmi_watchdog from a
local implementation to the global one provide by
kernel/watchdog.c.  This shift has caused a whole bunch of
compile problems under different config options.  I attempt to
simplify things with the patch below.

In order to simplify things, I had to come to terms with the
meaning of two terms ARCH_HAS_NMI_WATCHDOG and
CONFIG_HARDLOCKUP_DETECTOR.  Basically they mean the same thing,
the former on a local level and the latter on a global level.

With the old x86 nmi watchdog gone, there is no need to rely on
defining the ARCH_HAS_NMI_WATCHDOG variable because it doesn't
make sense any more.  x86 will now use the global
implementation.

The changes below do a few things.  First it changes the few
places that relied on ARCH_HAS_NMI_WATCHDOG to use
CONFIG_X86_LOCAL_APIC (the former was an alias for the latter
anyway, so nothing unusual here).  Those pieces of code were
relying more on local apic functionality the nmi watchdog
functionality, so the change should make sense.

Second, I removed the x86 implementation of
touch_nmi_watchdog().  It isn't need now, instead x86 will rely
on kernel/watchdog.c's implementation.

Third, I removed the #define ARCH_HAS_NMI_WATCHDOG itself from
x86.  And tweaked the include/linux/nmi.h file to tell users to
look for an externally defined touch_nmi_watchdog in the case of
ARCH_HAS_NMI_WATCHDOG _or_ CONFIG_HARDLOCKUP_DETECTOR. This
changes removes some of the ugliness in that file.

Finally, I added a Kconfig dependency for
CONFIG_HARDLOCKUP_DETECTOR that said you can't have
ARCH_HAS_NMI_WATCHDOG _and_ CONFIG_HARDLOCKUP_DETECTOR.  You can
only have one nmi_watchdog.

Tested with
ARCH=i386: allnoconfig, defconfig, allyesconfig, (various broken
configs) ARCH=x86_64: allnoconfig, defconfig, allyesconfig,
(various broken configs)

Hopefully, after this patch I won't get any more compile broken
emails. :-)

v3:
  changed a couple of 'linux/nmi.h' -> 'asm/nmi.h' to pick-up correct function
  prototypes when CONFIG_HARDLOCKUP_DETECTOR is not set.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: fweisbec@gmail.com
LKML-Reference: <1293044403-14117-1-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-22 22:15:32 +01:00
Robert Richter
da169f5df2 oprofile, x86: Add support for 6 counters (AMD family 15h)
This patch adds support for up to 6 hardware counters for AMD family
15h cpus. There is a new MSR range for hardware counters beginning at
MSRC001_0200 Performance Event Select (PERF_CTL0).

Signed-off-by: Robert Richter <robert.richter@amd.com>
2010-12-19 11:43:08 +01:00
Robert Richter
30570bced1 oprofile, x86: Add support for AMD family 15h
This patch adds support for AMD family 15h (Interlagos/Valencia/
Zambezi) cpus.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2010-12-19 11:43:04 +01:00
Ingo Molnar
ae51ce9061 Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/core 2010-11-18 20:07:12 +01:00
Soeren Sandmann Pedersen
9c0729dc80 x86: Eliminate bp argument from the stack tracing routines
The various stack tracing routines take a 'bp' argument in which the
caller is supposed to provide the base pointer to use, or 0 if doesn't
have one. Since bp is garbage whenever CONFIG_FRAME_POINTER is not
defined, this means all callers in principle should either always pass
0, or be conditional on CONFIG_FRAME_POINTER.

However, there are only really three use cases for stack tracing:

(a) Trace the current task, including IRQ stack if any
(b) Trace the current task, but skip IRQ stack
(c) Trace some other task

In all cases, if CONFIG_FRAME_POINTER is not defined, bp should just
be 0.  If it _is_ defined, then

- in case (a) bp should be gotten directly from the CPU's register, so
  the caller should pass NULL for regs,

- in case (b) the caller should should pass the IRQ registers to
  dump_trace(),

- in case (c) bp should be gotten from the top of the task's stack, so
  the caller should pass NULL for regs.

Hence, the bp argument is not necessary because the combination of
task and regs is sufficient to determine an appropriate value for bp.

This patch introduces a new inline function stack_frame(task, regs)
that computes the desired bp. This function is then called from the
two versions of dump_stack().

Signed-off-by: Soren Sandmann <ssp@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@infradead.org>,
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>,
LKML-Reference: <m3oc9rop28.fsf@dhcp-100-3-82.bos.redhat.com>>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-11-18 14:37:34 +01:00