Commit Graph

55 Commits

Author SHA1 Message Date
Priyanka Jain
3c83658ca9 powerpc/perf: Add e6500 PMU driver
e6500 core performance monitors has the following features:
- 6 performance monitor counters
- 512 events supported
- no threshold events

e6500 PMU has more specific events (Data L1 cache misses, Instruction L1
cache misses, etc ) than e500 PMU (which only had Data L1 cache reloads,
etc). Where available, the more specific events have been used which will
produce slightly different results than e500 PMU equivalents.

Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com>
Signed-off-by: Lijun Pan <Lijun.Pan@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-08-07 18:38:04 -05:00
Lijun Pan
5815c434fd powerpc/perf: add 2 additional performance monitor counters for e6500 core
There are 6 counters in e6500 core instead of 4 in e500 core.

Signed-off-by: Lijun Pan <Lijun.Pan@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-08-07 18:38:03 -05:00
Catalin Udma
96c3c9e78f powerpc/perf: increase the perf HW events to 6
This change is required after the e6500 perf support has been added.
There are 6 counters in e6500 core instead of 4 in e500 core and
the MAX_HWEVENTS counter should be changed accordingly from 4 to 6.
Added also runtime check for counters overflow.

Signed-off-by: Catalin Udma <catalin.udma@freescale.com>
Signed-off-by: Lijun Pan <Lijun.Pan@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
2013-08-07 18:38:03 -05:00
Linus Torvalds
560ae37178 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
 - fix for do_div() abuse on x86
 - locking fix in perf core
 - a pile of (build) fixes and cleanups in perf tools

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
  perf/x86: Fix incorrect use of do_div() in NMI warning
  perf: Fix perf_lock_task_context() vs RCU
  perf: Remove WARN_ON_ONCE() check in __perf_event_enable() for valid scenario
  perf: Clone child context from parent context pmu
  perf script: Fix broken include in Context.xs
  perf tools: Fix -ldw/-lelf link test when static linking
  perf tools: Revert regression in configuration of Python support
  perf tools: Fix perf version generation
  perf stat: Fix per-socket output bug for uncore events
  perf symbols: Fix vdso list searching
  perf evsel: Fix missing increment in sample parsing
  perf tools: Update symbol_conf.nr_events when processing attribute events
  perf tools: Fix new_term() missing free on error path
  perf tools: Fix parse_events_terms() segfault on error path
  perf evsel: Fix count parameter to read call in event_format__new
  perf tools: fix a typo of a Power7 event name
  perf tools: Fix -x/--exclude-other option for report command
  perf evlist: Enhance perf_evlist__start_workload()
  perf record: Remove -f/--force option
  perf record: Remove -A/--append option
  ...
2013-07-13 15:35:47 -07:00
Runzhen Wang
7e40c92019 perf tools: fix a typo of a Power7 event name
In the Power7 PMU guide:
https://www.power.org/documentation/commonly-used-metrics-for-performance-analysis/
PM_BRU_MPRED is referred to as PM_BR_MPRED.

It fixed the typo by changing the name of the event in kernel and
documentation accordingly.

This patch changes the ABI, there are some reasons I think it's ok:

- It is relatively new interface, specific to the Power7 platform.

- No tools that we know of actually use this interface at this point
 (none are listed near the interface).

- Users of this interface (eg oprofile users migrating to perf)
  would be more used to the "PM_BR_MPRED" rather than "PM_BRU_MPRED".

- These are in the ABI/testing at this point rather than ABI/stable,
  so hoping we have some wiggle room.

Signed-off-by: Runzhen Wang <runzhen@linux.vnet.ibm.com>
Acked-by: Michael Ellerman <michael@ellerman.id.au>
Cc: icycoder@gmail.com
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Runzhen Wang <runzhew@clemson.edu>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1372407297-6996-2-git-send-email-runzhen@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-07-08 17:40:05 -03:00
Linus Torvalds
65b97fb730 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc updates from Ben Herrenschmidt:
 "This is the powerpc changes for the 3.11 merge window.  In addition to
  the usual bug fixes and small updates, the main highlights are:

   - Support for transparent huge pages by Aneesh Kumar for 64-bit
     server processors.  This allows the use of 16M pages as transparent
     huge pages on kernels compiled with a 64K base page size.

   - Base VFIO support for KVM on power by Alexey Kardashevskiy

   - Wiring up of our nvram to the pstore infrastructure, including
     putting compressed oopses in there by Aruna Balakrishnaiah

   - Move, rework and improve our "EEH" (basically PCI error handling
     and recovery) infrastructure.  It is no longer specific to pseries
     but is now usable by the new "powernv" platform as well (no
     hypervisor) by Gavin Shan.

   - I fixed some bugs in our math-emu instruction decoding and made it
     usable to emulate some optional FP instructions on processors with
     hard FP that lack them (such as fsqrt on Freescale embedded
     processors).

   - Support for Power8 "Event Based Branch" facility by Michael
     Ellerman.  This facility allows what is basically "userspace
     interrupts" for performance monitor events.

   - A bunch of Transactional Memory vs.  Signals bug fixes and HW
     breakpoint/watchpoint fixes by Michael Neuling.

  And more ...  I appologize in advance if I've failed to highlight
  something that somebody deemed worth it."

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (156 commits)
  pstore: Add hsize argument in write_buf call of pstore_ftrace_call
  powerpc/fsl: add MPIC timer wakeup support
  powerpc/mpic: create mpic subsystem object
  powerpc/mpic: add global timer support
  powerpc/mpic: add irq_set_wake support
  powerpc/85xx: enable coreint for all the 64bit boards
  powerpc/8xx: Erroneous double irq_eoi() on CPM IRQ in MPC8xx
  powerpc/fsl: Enable CONFIG_E1000E in mpc85xx_smp_defconfig
  powerpc/mpic: Add get_version API both for internal and external use
  powerpc: Handle both new style and old style reserve maps
  powerpc/hw_brk: Fix off by one error when validating DAWR region end
  powerpc/pseries: Support compression of oops text via pstore
  powerpc/pseries: Re-organise the oops compression code
  pstore: Pass header size in the pstore write callback
  powerpc/powernv: Fix iommu initialization again
  powerpc/pseries: Inform the hypervisor we are using EBB regs
  powerpc/perf: Add power8 EBB support
  powerpc/perf: Core EBB support for 64-bit book3s
  powerpc/perf: Drop MMCRA from thread_struct
  powerpc/perf: Don't enable if we have zero events
  ...
2013-07-04 10:29:23 -07:00
Linus Torvalds
f0bb4c0ab0 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
 "Kernel improvements:

   - watchdog driver improvements by Li Zefan
   - Power7 CPI stack events related improvements by Sukadev Bhattiprolu
   - event multiplexing via hrtimers and other improvements by Stephane
     Eranian
   - kernel stack use optimization by Andrew Hunter
   - AMD IOMMU uncore PMU support by Suravee Suthikulpanit
   - NMI handling rate-limits by Dave Hansen
   - various hw_breakpoint fixes by Oleg Nesterov
   - hw_breakpoint overflow period sampling and related signal handling
     fixes by Jiri Olsa
   - Intel Haswell PMU support by Andi Kleen

  Tooling improvements:

   - Reset SIGTERM handler in workload child process, fix from David
     Ahern.
   - Makefile reorganization, prep work for Kconfig patches, from Jiri
     Olsa.
   - Add automated make test suite, from Jiri Olsa.
   - Add --percent-limit option to 'top' and 'report', from Namhyung
     Kim.
   - Sorting improvements, from Namhyung Kim.
   - Expand definition of sysfs format attribute, from Michael Ellerman.

  Tooling fixes:

   - 'perf tests' fixes from Jiri Olsa.
   - Make Power7 CPI stack events available in sysfs, from Sukadev
     Bhattiprolu.
   - Handle death by SIGTERM in 'perf record', fix from David Ahern.
   - Fix printing of perf_event_paranoid message, from David Ahern.
   - Handle realloc failures in 'perf kvm', from David Ahern.
   - Fix divide by 0 in variance, from David Ahern.
   - Save parent pid in thread struct, from David Ahern.
   - Handle JITed code in shared memory, from Andi Kleen.
   - Fixes for 'perf diff', from Jiri Olsa.
   - Remove some unused struct members, from Jiri Olsa.
   - Add missing liblk.a dependency for python/perf.so, fix from Jiri
     Olsa.
   - Respect CROSS_COMPILE in liblk.a, from Rabin Vincent.
   - No need to do locking when adding hists in perf report, only 'top'
     needs that, from Namhyung Kim.
   - Fix alignment of symbol column in in the hists browser (top,
     report) when -v is given, from NAmhyung Kim.
   - Fix 'perf top' -E option behavior, from Namhyung Kim.
   - Fix bug in isupper() and islower(), from Sukadev Bhattiprolu.
   - Fix compile errors in bp_signal 'perf test', from Sukadev
     Bhattiprolu.

  ... and more things"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (102 commits)
  perf/x86: Disable PEBS-LL in intel_pmu_pebs_disable()
  perf/x86: Fix shared register mutual exclusion enforcement
  perf/x86/intel: Support full width counting
  x86: Add NMI duration tracepoints
  perf: Drop sample rate when sampling is too slow
  x86: Warn when NMI handlers take large amounts of time
  hw_breakpoint: Introduce "struct bp_cpuinfo"
  hw_breakpoint: Simplify *register_wide_hw_breakpoint()
  hw_breakpoint: Introduce cpumask_of_bp()
  hw_breakpoint: Simplify the "weight" usage in toggle_bp_slot() paths
  hw_breakpoint: Simplify list/idx mess in toggle_bp_slot() paths
  perf/x86/intel: Add mem-loads/stores support for Haswell
  perf/x86/intel: Support Haswell/v4 LBR format
  perf/x86/intel: Move NMI clearing to end of PMI handler
  perf/x86/intel: Add Haswell PEBS support
  perf/x86/intel: Add simple Haswell PMU support
  perf/x86/intel: Add Haswell PEBS record support
  perf/x86/intel: Fix sparse warning
  perf/x86/amd: AMD IOMMU Performance Counter PERF uncore PMU implementation
  perf/x86/amd: Add IOMMU Performance Counter resource management
  ...
2013-07-02 16:15:23 -07:00
Michael Ellerman
4df4899911 powerpc/perf: Add power8 EBB support
Add logic to the power8 PMU code to support EBB. Future processors would
also be expected to implement similar constraints. At that time we could
possibly factor these out into common code.

Finally mark the power8 PMU as supporting EBB, which is the actual
enable switch which allows EBBs to be configured.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01 11:50:13 +10:00
Michael Ellerman
330a1eb777 powerpc/perf: Core EBB support for 64-bit book3s
Add support for EBB (Event Based Branches) on 64-bit book3s. See the
included documentation for more details.

EBBs are a feature which allows the hardware to branch directly to a
specified user space address when a PMU event overflows. This can be
used by programs for self-monitoring with no kernel involvement in the
inner loop.

Most of the logic is in the generic book3s code, primarily to avoid a
proliferation of PMU callbacks.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01 11:50:10 +10:00
Michael Ellerman
4ea355b536 powerpc/perf: Don't enable if we have zero events
In power_pmu_enable() we still enable the PMU even if we have zero
events. This should have no effect but doesn't make much sense. Instead
just return after telling the hypervisor that we are not using the PMCs.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
CC: <stable@vger.kernel.org> [v3.10]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01 11:50:03 +10:00
Michael Ellerman
0a48843d6c powerpc/perf: Use existing out label in power_pmu_enable()
In power_pmu_enable() we can use the existing out label to reduce the
number of return paths.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
CC: <stable@vger.kernel.org> [v3.10]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01 11:50:00 +10:00
Michael Ellerman
7a7a41f9d5 powerpc/perf: Freeze PMC5/6 if we're not using them
On Power8 we can freeze PMC5 and 6 if we're not using them. Normally they
run all the time.

As noticed by Anshuman, we should unfreeze them when we disable the PMU
as there are legacy tools which expect them to run all the time.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
CC: <stable@vger.kernel.org> [v3.10]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01 11:49:57 +10:00
Michael Ellerman
378a6ee99e powerpc/perf: Rework disable logic in pmu_disable()
In pmu_disable() we disable the PMU by setting the FC (Freeze Counters)
bit in MMCR0. In order to do this we have to read/modify/write MMCR0.

It's possible that we read a value from MMCR0 which has PMAO (PMU Alert
Occurred) set. When we write that value back it will cause an interrupt
to occur. We will then end up in the PMU interrupt handler even though
we are supposed to have just disabled the PMU.

We can avoid this by making sure we never write PMAO back. We should not
lose interrupts because when the PMU is re-enabled the overflowed values
will cause another interrupt.

We also reorder the clearing of SAMPLE_ENABLE so that is done after the
PMU is frozen. Otherwise there is a small window between the clearing of
SAMPLE_ENABLE and the setting of FC where we could take an interrupt and
incorrectly see SAMPLE_ENABLE not set. This would for example change the
logic in perf_read_regs().

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
CC: <stable@vger.kernel.org> [v3.10]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01 11:49:54 +10:00
Michael Ellerman
d8bec4c9cd powerpc/perf: Check that events only include valid bits on Power8
A mistake we have made in the past is that we pull out the fields we
need from the event code, but don't check that there are no unknown bits
set. This means that we can't ever assign meaning to those unknown bits
in future.

Although we have once again failed to do this at release, it is still
early days for Power8 so I think we can still slip this in and get away
with it.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
CC: <stable@vger.kernel.org> [v3.10]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01 11:49:50 +10:00
Paul Gortmaker
061d19f279 powerpc: Delete __cpuinit usage from all users
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the powerpc uses of the __cpuinit macros.  There
are no __CPUINIT users in assembly files in powerpc.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01 11:10:36 +10:00
Michael Ellerman
6772faa1ba powerpc/perf: Fix deadlock caused by calling printk() in PMU exception
In commit bc09c21 "Fix finding overflowed PMC in interrupt" we added
a printk() to the PMU exception handler. Unfortunately that is not safe.

The problem is that the PMU exception may run even when interrupts are
soft disabled, aka NMI context. We do this so that we can profile parts
of the kernel that have interrupts soft-disabled.

But by calling printk() from the exception handler, we can potentially
deadlock in the printk code on logbuf_lock, eg:

  [c00000038ba575c0] c000000000081928 .vprintk_emit+0xa8/0x540
  [c00000038ba576a0] c0000000007bcde8 .printk+0x48/0x58
  [c00000038ba57710] c000000000076504 .perf_event_interrupt+0x2d4/0x490
  [c00000038ba57810] c00000000001f6f8 .performance_monitor_exception+0x48/0x60
  [c00000038ba57880] c0000000000032cc performance_monitor_common+0x14c/0x180
  --- Exception: f01 (Performance Monitor) at c0000000007b25d4 ._raw_spin_lock_irq
  +0x64/0xc0
  [c00000038ba57bf0] c00000000007ed90 .devkmsg_read+0xd0/0x5a0
  [c00000038ba57d00] c0000000001c2934 .vfs_read+0xc4/0x1e0
  [c00000038ba57d90] c0000000001c2cd8 .SyS_read+0x58/0xd0
  [c00000038ba57e30] c000000000009d54 syscall_exit+0x0/0x98
  --- Exception: c01 (System Call) at 00001fffffbf6f7c
  SP (3ffff6d4de10) is in userspace

Fix it by making sure we only call printk() when we are not in NMI
context.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Cc: <stable@vger.kernel.org> # 3.9
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-10 08:36:32 +10:00
Michael Ellerman
58a032c3b1 powerpc/perf: Add missing SIER support
Commit 8f61aa3 "Add support for SIER" missed updates to siar_valid()
and perf_get_data_addr().

In both cases we need to check the SIER instead of mmcra.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-01 08:29:29 +10:00
Michael Ellerman
cbda6aa10b powerpc/perf: Revert to original NO_SIPR logic
This is a revert and then some of commit 860aad7 "Add regs_no_sipr()".
This workaround was only needed on early chip versions.

As before NO_SIPR becomes a static flag of the PMU struct.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-01 08:29:29 +10:00
Sukadev Bhattiprolu
bd1060eb7b perf: Power7: Make CPI stack events available in sysfs
A set of Power7 events are often used for Cycles Per Instruction (CPI) stack
analysis. Make these events available in sysfs (/sys/devices/cpu/events/) so
they can be identified using their symbolic names:

	perf stat -e 'cpu/PM_CMPLU_STALL_DCACHE_MISS/' /bin/ls

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@ozlabs.org
Link: http://lkml.kernel.org/r/20130406164803.GA408@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-05-29 16:04:18 +03:00
Michael Neuling
691231846c powerpc/perf: Fix setting of "to" addresses for BHRB
Currently we only set the "to" address in the branch stack when the CPU
explicitly gives us a value.  Unfortunately it only does this for XL form
branches (eg blr, bctr, bctar) and not I and B form branches (eg b, bc).

Fortunately if we read the instruction from memory we can extract the offset of
a branch and calculate the target address.

This adds a function power_pmu_bhrb_to() to calculate the target/to address of
the corresponding I and B form branches.  It handles branches in both user and
kernel spaces.  It also plumbs this into the perf brhb reading code.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 16:00:22 +10:00
Michael Neuling
506e70d132 powerpc/pmu: Fix order of interpreting BHRB target entries
The current Branch History Rolling Buffer (BHRB) code misinterprets the order
of entries in the hardware buffer.  It assumes that a branch target address
will be read _after_ its corresponding branch.  In reality the branch target
comes before (lower mfbhrb entry) it's corresponding branch.

This is a rewrite of the code to take this into account.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 16:00:22 +10:00
Michael Neuling
d52f2dc40b powerpc/perf: Move BHRB code into CONFIG_PPC64 region
The new Branch History Rolling buffer (BHRB) code is only useful on 64bit
processors, so move it into the #ifdef CONFIG_PPC64 region.

This avoids code bloat on 32bit systems.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 16:00:21 +10:00
Anshuman Khandual
3925f46bb5 powerpc/perf: Enable branch stack sampling framework
Provides basic enablement for perf branch stack sampling framework on
POWER8 processor based platforms. Adds new BHRB related elements into
cpu_hw_event structure to represent current BHRB config, BHRB filter
configuration, manage context and to hold output BHRB buffer during
PMU interrupt before passing to the user space. This also enables
processing of BHRB data and converts them into generic perf branch
stack data format.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26 16:13:02 +10:00
Anshuman Khandual
b1113557fb powerpc/perf: Define BHRB generic functions, data and flags for POWER8
This patch populates BHRB specific data for power_pmu structure. It
also implements POWER8 specific BHRB filter and configuration functions.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26 16:13:01 +10:00
Anshuman Khandual
73760931dc powerpc/perf: Add basic assembly code to read BHRB entries on POWER8
This patch adds the basic assembly code to read BHRB buffer. BHRB entries
are valid only after a PMU interrupt has happened (when MMCR0[PMAO]=1)
and BHRB has been freezed. BHRB read should not be attempted when it is
still enabled (MMCR0[PMAE]=1) and getting updated, as this can produce
non-deterministic results.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26 16:11:11 +10:00
Michael Ellerman
e05b9b9e5c powerpc/perf: Power8 PMU support
This patch adds support for the power8 PMU to perf.

Work is ongoing to add generic cache events.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26 16:11:10 +10:00
Michael Ellerman
8f61aa325f powerpc/perf: Add support for SIER
On power8 we have a new SIER (Sampled Instruction Event Register), which
captures information about instructions when we have random sampling
enabled.

Add support for loading the SIER into pt_regs, overloading regs->dar.
Also set the new NO_SIPR flag in regs->result if we don't have SIPR.

Update regs_sihv/sipr() to look for SIPR/SIHV in SIER.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26 16:11:10 +10:00
Michael Ellerman
860aad71fc powerpc/perf: Add regs_no_sipr()
On power8 the presence or absence of SIPR depends on settings at runtime,
so convert to using a dynamic flag for NO_SIPR. Existing backends that
set NO_SIPR unconditionally set the dynamic flag obviously.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26 16:11:09 +10:00
Michael Ellerman
33904054b4 powerpc/perf: Add an accessor for regs->result
Add an accessor for regs->result so we can use it to store more flags in
future.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26 16:11:08 +10:00
Michael Ellerman
5682c46026 powerpc/perf: Convert mmcra_sipr/sihv() to regs_sipr/sihv()
On power8 the SIPR and SIHV are not in MMCRA, so convert the routines
to take regs and change the names accordingly.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26 16:11:08 +10:00
Michael Ellerman
7a7868326d powerpc/perf: Add an explict flag indicating presence of SLOT field
In perf_ip_adjust() we potentially use the MMCRA[SLOT] field to adjust
the reported IP of a sampled instruction.

Currently the logic is written so that if the backend does NOT have
the PPMU_ALT_SIPR flag set then we assume MMCRA[SLOT] exists.

However on power8 we do not want to set ALT_SIPR (it's in a third
location), and we also do not have MMCRA[SLOT].

So add a new flag which only indicates whether MMCRA[SLOT] exists.

Naively we'd set it on everything except power6/7, because they set
ALT_SIPR, and we've reversed the polarity of the flag. But it's more
complicated than that.

mpc7450 is 32-bit, and uses its own version of perf_ip_adjust()
which doesn't use MMCRA[SLOT], so it doesn't need the new flag set and
the behaviour is unchanged.

PPC970 (and I assume power4) don't have MMCRA[SLOT], so shouldn't have
the new flag set. This is a behaviour change on those cpus, though we
were probably getting lucky and the bits in question were 0.

power5 and power5+ set the new flag, behaviour unchanged.

power6 & power7 do not set the new flag, behaviour unchanged.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-04-26 16:11:07 +10:00
Ingo Molnar
a0bf225db7 perf/urgent fixes:
. perf probe: Fix segfault due to testing the wrong pointer for NULL,
   from Ananth N Mavinakayanahalli.
 
 . libtraceevent: Remove hard coded include to /usr/local/include in
   Makefile, which causes cross builds to include host header files,
   fix from Jack Mitchell.
 
 . perf record: Use the right target interface for synthesizing
   threads when --cpu/-C option is used, fix from Jiri Olsa.
 
 . Check if -DFORTIFY_SOURCE=2 is allowed, as gcc 4.7.2 defines
   it and then the build is broken when it is redefined in perf,
   fix from Marcin Slusarz.
 
 . Fix build with NO_NEWT=1, that can happen explicitely or when
   the newt-devel package is not installed, from Michael Ellerman.
 
 . perf/POWER7: Create a sysfs format entry for Power7 events, missing
   patch from a patchseries already merged, from Sukadev Bhattiprolu.
 
 . Fix LIBNUMA build with glibc 2.12 and older, from Vinson Lee.
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

. perf probe: Fix segfault due to testing the wrong pointer for NULL,
  from Ananth N Mavinakayanahalli.

. libtraceevent: Remove hard coded include to /usr/local/include in
  Makefile, which causes cross builds to include host header files,
  fix from Jack Mitchell.

. perf record: Use the right target interface for synthesizing
  threads when --cpu/-C option is used, fix from Jiri Olsa.

. Check if -DFORTIFY_SOURCE=2 is allowed, as gcc 4.7.2 defines
  it and then the build is broken when it is redefined in perf,
  fix from Marcin Slusarz.

. Fix build with NO_NEWT=1, that can happen explicitely or when
  the newt-devel package is not installed, from Michael Ellerman.

. perf/POWER7: Create a sysfs format entry for Power7 events, missing
  patch from a patchseries already merged, from Sukadev Bhattiprolu.

. Fix LIBNUMA build with glibc 2.12 and older, from Vinson Lee.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-03-18 10:00:56 +01:00
Sukadev Bhattiprolu
3bf7b07ece perf/POWER7: Create a sysfs format entry for Power7 events
Create a sysfs entry, '/sys/bus/event_source/devices/cpu/format/event'
which describes the format of the POWER7 PMU events.

This code is based on corresponding code in x86.

Changelog[v4]:  [Michael Ellerman, Paul Mckerras] The event format is different
		for other POWER cpus. So move the code to POWER7-specific,
		power7-pmu.c Also, the POWER7 format uses bits 0-19 not 0-20.

Changelog[v2]: [Jiri Osla] Use PMU_FORMAT_ATTR rather than duplicating code.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Tested-by: Michael Ellerman <michael@ellerman.id.au>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anton Blanchard <anton@au1.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: benh@kernel.crashing.org
Cc: linuxppc-dev@ozlabs.org
Link: http://lkml.kernel.org/r/20130306054826.GA14627@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-03-13 17:01:04 -03:00
Linus Torvalds
9d3cae26ac Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc updates from Benjamin Herrenschmidt:
 "So from the depth of frozen Minnesota, here's the powerpc pull request
  for 3.9.  It has a few interesting highlights, in addition to the
  usual bunch of bug fixes, minor updates, embedded device tree updates
  and new boards:

   - Hand tuned asm implementation of SHA1 (by Paulus & Michael
     Ellerman)

   - Support for Doorbell interrupts on Power8 (kind of fast
     thread-thread IPIs) by Ian Munsie

   - Long overdue cleanup of the way we handle relocation of our open
     firmware trampoline (prom_init.c) on 64-bit by Anton Blanchard

   - Support for saving/restoring & context switching the PPR (Processor
     Priority Register) on server processors that support it.  This
     allows the kernel to preserve thread priorities established by
     userspace.  By Haren Myneni.

   - DAWR (new watchpoint facility) support on Power8 by Michael Neuling

   - Ability to change the DSCR (Data Stream Control Register) which
     controls cache prefetching on a running process via ptrace by
     Alexey Kardashevskiy

   - Support for context switching the TAR register on Power8 (new
     branch target register meant to be used by some new specific
     userspace perf event interrupt facility which is yet to be enabled)
     by Ian Munsie.

   - Improve preservation of the CFAR register (which captures the
     origin of a branch) on various exception conditions by Paulus.

   - Move the Bestcomm DMA driver from arch powerpc to drivers/dma where
     it belongs by Philippe De Muyter

   - Support for Transactional Memory on Power8 by Michael Neuling
     (based on original work by Matt Evans).  For those curious about
     the feature, the patch contains a pretty good description."

(See commit db8ff90702: "powerpc: Documentation for transactional
memory on powerpc" for the mentioned description added to the file
Documentation/powerpc/transactional_memory.txt)

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (140 commits)
  powerpc/kexec: Disable hard IRQ before kexec
  powerpc/85xx: l2sram - Add compatible string for BSC9131 platform
  powerpc/85xx: bsc9131 - Correct typo in SDHC device node
  powerpc/e500/qemu-e500: enable coreint
  powerpc/mpic: allow coreint to be determined by MPIC version
  powerpc/fsl_pci: Store the pci ctlr device ptr in the pci ctlr struct
  powerpc/85xx: Board support for ppa8548
  powerpc/fsl: remove extraneous DIU platform functions
  arch/powerpc/platforms/85xx/p1022_ds.c: adjust duplicate test
  powerpc: Documentation for transactional memory on powerpc
  powerpc: Add transactional memory to pseries and ppc64 defconfigs
  powerpc: Add config option for transactional memory
  powerpc: Add transactional memory to POWER8 cpu features
  powerpc: Add new transactional memory state to the signal context
  powerpc: Hook in new transactional memory code
  powerpc: Routines for FP/VSX/VMX unavailable during a transaction
  powerpc: Add transactional memory unavaliable execption handler
  powerpc: Add reclaim and recheckpoint functions for context switching transactional memory processes
  powerpc: Add FP/VSX and VMX register load functions for transactional memory
  powerpc: Add helper functions for transactional memory context switching
  ...
2013-02-23 17:09:55 -08:00
Sukadev Bhattiprolu
886c3b2d67 perf/POWER7: Make some POWER7 events available in sysfs
Make some POWER7-specific perf events available in sysfs.

	$ /bin/ls -1 /sys/bus/event_source/devices/cpu/events/
	branch-instructions
	branch-misses
	cache-misses
	cache-references
	cpu-cycles
	instructions
	PM_BRU_FIN
	PM_BRU_MPRED
	PM_CMPLU_STALL
	PM_CYC
	PM_GCT_NOSLOT_CYC
	PM_INST_CMPL
	PM_LD_MISS_L1
	PM_LD_REF_L1
	stalled-cycles-backend
	stalled-cycles-frontend

where the 'PM_*' events are POWER specific and the others are the
generic events.

This will enable users to specify these events with their symbolic
names rather than with their raw code.

	perf stat -e 'cpu/PM_CYC' ...

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anton Blanchard <anton@au1.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: linuxppc-dev@ozlabs.org
Link: http://lkml.kernel.org/r/20130123062528.GE13720@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-01-31 13:07:51 -03:00
Sukadev Bhattiprolu
1c53a27072 perf/POWER7: Make generic event translations available in sysfs
Make the generic perf events in POWER7 available via sysfs.

	$ ls /sys/bus/event_source/devices/cpu/events
	branch-instructions
	branch-misses
	cache-misses
	cache-references
	cpu-cycles
	instructions
	stalled-cycles-backend
	stalled-cycles-frontend

	$ cat /sys/bus/event_source/devices/cpu/events/cache-misses
	event=0x400f0

This patch is based on commits that implement this functionality on x86.
Eg:
	commit a47473939d
	Author: Jiri Olsa <jolsa@redhat.com>
	Date:   Wed Oct 10 14:53:11 2012 +0200

	    perf/x86: Make hardware event translations available in sysfs

Changelog:[v2]
	[Jiri Osla] Drop EVENT_ID() macro since it is only used once.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anton Blanchard <anton@au1.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: linuxppc-dev@ozlabs.org
Link: http://lkml.kernel.org/r/20130123062454.GD13720@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-01-31 13:07:50 -03:00
Sukadev Bhattiprolu
bbdc7aa442 perf/Power7: Use macros to identify perf events
Define and use macros to identify perf events codes This would make it
easier and more readable when these event codes need to be used in more
than one place.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anton Blanchard <anton@au1.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: linuxppc-dev@ozlabs.org
Link: http://lkml.kernel.org/r/20130123062353.GB13720@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-01-31 13:07:50 -03:00
sukadev@linux.vnet.ibm.com
f53d168c02 perf/Power: PERF_EVENT_IOC_ENABLE does not reenable event
perf/Power: PERF_EVENT_IOC_ENABLE does not reenable event

If we disable a perf event because we exceeded the specified ->event_limit,
power_pmu_stop() sets the PERF_HES_STOPPED flag on the event.

If the application then re-enables the event using PERF_EVENT_IOC_ENABLE
ioctl, we don't ever clear this STOPPED flag. Consequently, the user space
is never notified of the event.

Following message has more background and test case.

    http://lists.eecs.utk.edu/pipermail/ptools-perfapi/2012-October/002528.html

Used the following test cases to verify that this patch works on latest PAPI.

	$ papi.git/src/ctests/nonthread PAPI_TOT_CYC@5000000

	$ papi.git/src/ctests/overflow_single_event

Changelog[v2]:
	- [Paul Mackerras] Also clear PERF_HES_UPTODATE flag since we are
	  restarting the event; cleanup comments and patch description.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-29 11:35:07 +11:00
Michael Neuling
e13e895f84 powerpc/perf: Fix for PMCs not making progress
On POWER7 when we have really small counts left before overflow, we can take a
PMU IRQ, but the PMC gets wound back to just before the overflow.

If the kernel is setting the PMC to a value just before the overflow, we can
get interrupted again without the PMC making any progress (ie another buggy
overflow).  In this case, we can end up making no forward progress, with the
PMC interrupt returning us to the same count over and over.

The below detects when we are making no forward progress (ie. delta = 0) and
then increases the amount left before the overflow.  This stops us from locking
up.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
cc: Paul Mackerras <paulus@samba.org>
cc: Anton Blanchard <anton@samba.org>
cc: Linux PPC dev <linuxppc-dev@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-10 17:02:04 +11:00
Michael Neuling
bc09c219b2 powerpc/perf: Fix finding overflowed PMC in interrupt
If a PMC is about to overflow on a counter that's on an active perf event
(ie. less than 256 from the end) and a _different_ PMC overflows just at this
time (a PMC that's not on an active perf event), we currently mark the event as
found, but in reality it's not as it's likely the other PMC that caused the
IRQ.  Since we mark it as found the second catch all for overflows doesn't run,
and we don't reset the overflowing PMC ever.  Hence we keep hitting that same
PMC IRQ over and over and don't reset the actual overflowing counter.

This is a rewrite of the perf interrupt handler for book3s to get around this.
We now check to see if any of the PMCs have actually overflowed (ie >=
0x80000000).  If yes, record it for active counters and just reset it for
inactive counters.  If it's not overflowed, then we check to see if it's one of
the buggy power7 counters and if it is, record it and continue.  If none of the
PMCs match this, then we make note that we couldn't find the PMC that caused
the IRQ.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
cc: Paul Mackerras <paulus@samba.org>
cc: Anton Blanchard <anton@samba.org>
cc: Linux PPC dev <linuxppc-dev@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-10 17:02:01 +11:00
Chris Freehill
15fab56eca powerpc/perf: Add stalled-cycles events
Support for stalled-cycles-frontend and stalled-cycles-backend is
added for e500-based processors.

The following mappings are used:

stalled-cycles-frontend or idle-cycles-frontend:
Com:18 Cycles decode stalled

stalled-cycles-backend or idle-cycles-backend
Com:19 cycles issue stalled

Signed-off-by: Chris Freehill <chrisf@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-10 17:00:56 +11:00
Michael Ellerman
da11195779 powerpc/perf: Add missing L2 constraint handling in Power7 PMU
If we have two cache events that require different settings of the L2SEL
bits in MMCR1 then we can not schedule those events simultaneously. Add
logic to the constraint handling to express that.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15 13:00:36 +11:00
Benjamin Herrenschmidt
72523d8082 Revert "powerpc/perf: Use pmc_overflow() to detect rolled back events"
This reverts commit 813312110b.

This revert was requested by the author of the patch as it seems
to cause system hangs with some low frequency events
2012-10-18 10:36:11 +11:00
sukadev@linux.vnet.ibm.com
e6878835ac powerpc/perf: Sample only if SIAR-Valid bit is set in P7+
powerpc/perf: Sample only if SIAR-Valid bit is set in P7+

On POWER7+ two new bits (mmcra[35] and mmcra[36]) indicate whether the
contents of SIAR and SDAR are valid.

For marked instructions on P7+, we must save the contents of SIAR and
SDAR registers only if these new bits are set.

This code/check for the SIAR-Valid bit is specific to P7+, so rather than
waste a CPU-feature bit use the PVR flag.

Note that Carl Love proposed a similar change for oprofile:

        https://lkml.org/lkml/2012/6/22/309

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-27 12:51:05 +10:00
Benjamin Herrenschmidt
fff34b3412 Merge branch 'merge' into next
Brings in various bug fixes from 3.6-rcX
2012-09-07 09:48:59 +10:00
Michael Ellerman
d3dbeef657 powerpc: Rename 64-bit PVR constants to PVR_foo
We have an old FIXME in reg.h which points out that we should standardise
on PVR_foo for our PVR #defines. Currently we use PVR_ on 32-bit and PV_
on 64-bit.

So do that rename and remove the FIXME.

Seeing as we're touching all but one usage of __is_processor(), rename it
to something less ugly and more indicative of what it does, which is
simply to check the PVR version.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-05 15:19:35 +10:00
Sukadev Bhattiprolu
813312110b powerpc/perf: Use pmc_overflow() to detect rolled back events
For certain speculative events on Power7, 'perf stat' reports far higher
event count than 'perf record' for the same event.

As described in following commit, a performance monitor exception is raised
even when the the performance events are rolled back.

        commit 0837e3242c
        Author: Anton Blanchard <anton@samba.org>
        Date:   Wed Mar 9 14:38:42 2011 +1100

perf_event_interrupt() records an event only when an overflow occurs. But
this check for overflow is a simple 'if (val < 0)'.

Because the events are rolled back, this check for overflow fails and the
event is not recorded. perf_event_interrupt() later uses pmc_overflow() to
detect the overflow and resets the counters and the events are lost completely.

To properly detect the overflow of rolled back events, use pmc_overflow()
even when recording events.

To reproduce:
        $ cat strcpy.c
        #include <stdio.h>
        #include <string.h>
        main()
        {
                char buf[256];

                alarm(5);
                while(1)
                        strcpy(buf, "string1");
        }

        $ perf record -e r20014 ./strcpy
        $ perf report -n > report.1
        $ perf stat -e r20014 > report.2
        # Compare report.1 and report.2

Reported-by: Maynard Johnson <mpjohn@us.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-08-24 20:26:10 +10:00
Anton Blanchard
6da7094810 powerpc/perf: Use perf_instruction_pointer in callchains
We use SIAR or regs->nip for the instruction pointer depending on
the PMU configuration, but we always use regs->nip in the callchain.

Use perf_instruction_pointer so the backtrace is consistent.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-07-10 19:18:46 +10:00
Anton Blanchard
5c093efa6f powerpc/perf: Always use pt_regs for userspace samples
At the moment we always use the SIAR if the PMU supports continuous
sampling. Unfortunately the SIAR and the PMU exception are not
synchronised for non marked events so we can end up with callchains
that dont make sense.

The following patch checks the HV and PR bits for samples coming from
userspace and always uses pt_regs for them. Userspace will never have
interrupts off so there is no real advantage to using the SIAR for
non marked events in userspace.

I had experimented with a patch that did a similar thing for kernel
samples but we lost a significant amount of information. I was
unable to profile any of our early exception code for example.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-07-10 19:18:43 +10:00
Anton Blanchard
75382aa72f powerpc/perf: Move code to select SIAR or pt_regs into perf_read_regs
The logic to choose whether to use the SIAR or get the information
out of pt_regs is going to get more complicated, so do it once in
perf_read_regs.

We overload regs->result which is gross but we are already doing it
with regs->dsisr.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-07-10 19:18:41 +10:00