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Cascade Lake Xeon parts have the same model number as Skylake Xeon
parts, so they are tagged with the intel_pebs_isolation
quirk. However, as with Skylake Xeon H0 stepping parts, the PEBS
isolation issue is fixed in all microcode versions.
Add the Cascade Lake Xeon steppings (5, 6, and 7) to the
isolation_ucodes[] table so that these parts benefit from Andi's
optimization in commit 9b545c04ab ("perf/x86/kvm: Avoid unnecessary
work in guest filtering").
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/20210205191324.2889006-1-jmattson@google.com
With Architectural Performance Monitoring Version 5, CPUID 10.ECX cpu
leaf indicates the fixed counter enumeration. This extends the previous
count to a bitmap which allows disabling even lower fixed counters.
It could be used by a Hypervisor.
The existing intel_ctrl variable is used to remember the bitmask of the
counters. All code that reads all counters is fixed to check this extra
bitmask.
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Originally-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1611873611-156687-6-git-send-email-kan.liang@linux.intel.com
Add perf core PMU support for the Intel Sapphire Rapids server, which is
the successor of the Intel Ice Lake server. The enabling code is based
on Ice Lake, but there are several new features introduced.
The event encoding is changed and simplified, e.g., the event codes
which are below 0x90 are restricted to counters 0-3. The event codes
which above 0x90 are likely to have no restrictions. The event
constraints, extra_regs(), and hardware cache events table are changed
accordingly.
A new Precise Distribution (PDist) facility is introduced, which
further minimizes the skid when a precise event is programmed on the GP
counter 0. Enable the Precise Distribution (PDist) facility with :ppp
event. For this facility to work, the period must be initialized with a
value larger than 127. Add spr_limit_period() to apply the limit for
:ppp event.
Two new data source fields, data block & address block, are added in the
PEBS Memory Info Record for the load latency event. To enable the
feature,
- An auxiliary event has to be enabled together with the load latency
event on Sapphire Rapids. A new flag PMU_FL_MEM_LOADS_AUX is
introduced to indicate the case. A new event, mem-loads-aux, is
exposed to sysfs for the user tool.
Add a check in hw_config(). If the auxiliary event is not detected,
return an unique error -ENODATA.
- The union perf_mem_data_src is extended to support the new fields.
- Ice Lake and earlier models do not support block information, but the
fields may be set by HW on some machines. Add pebs_no_block to
explicitly indicate the previous platforms which don't support the new
block fields. Accessing the new block fields are ignored on those
platforms.
A new store Latency facility is introduced, which leverages the PEBS
facility where it can provide additional information about sampled
stores. The additional information includes the data address, memory
auxiliary info (e.g. Data Source, STLB miss) and the latency of the
store access. To enable the facility, the new event (0x02cd) has to be
programed on the GP counter 0. A new flag PERF_X86_EVENT_PEBS_STLAT is
introduced to indicate the event. The store_latency_data() is introduced
to parse the memory auxiliary info.
The layout of access latency field of PEBS Memory Info Record has been
changed. Two latency, instruction latency (bit 15:0) and cache access
latency (bit 47:32) are recorded.
- The cache access latency is similar to previous memory access latency.
For loads, the latency starts by the actual cache access until the
data is returned by the memory subsystem.
For stores, the latency starts when the demand write accesses the L1
data cache and lasts until the cacheline write is completed in the
memory subsystem.
The cache access latency is stored in low 32bits of the sample type
PERF_SAMPLE_WEIGHT_STRUCT.
- The instruction latency starts by the dispatch of the load operation
for execution and lasts until completion of the instruction it belongs
to.
Add a new flag PMU_FL_INSTR_LATENCY to indicate the instruction
latency support. The instruction latency is stored in the bit 47:32
of the sample type PERF_SAMPLE_WEIGHT_STRUCT.
Extends the PERF_METRICS MSR to feature TMA method level 2 metrics. The
lower half of the register is the TMA level 1 metrics (legacy). The
upper half is also divided into four 8-bit fields for the new level 2
metrics. Expose all eight Topdown metrics events to user space.
The full description for the SPR features can be found at Intel
Architecture Instruction Set Extensions and Future Features
Programming Reference, 319433-041.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1611873611-156687-5-git-send-email-kan.liang@linux.intel.com
Intel Sapphire Rapids server will introduce 8 metrics events. Intel
Ice Lake only supports 4 metrics events. A perf tool user may mistakenly
use the unsupported events via RAW format on Ice Lake. The user can
still get a value from the unsupported Topdown metrics event once the
following Sapphire Rapids enabling patch is applied.
To enable the 8 metrics events on Intel Sapphire Rapids, the
INTEL_TD_METRIC_MAX has to be updated, which impacts the
is_metric_event(). The is_metric_event() is a generic function.
On Ice Lake, the newly added SPR metrics events will be mistakenly
accepted as metric events on creation. At runtime, the unsupported
Topdown metrics events will be updated.
Add a variable num_topdown_events in x86_pmu to indicate the available
number of the Topdown metrics event on the platform. Apply the number
into is_metric_event(). Only the supported Topdown metrics events
should be created as metrics events.
Apply the num_topdown_events in icl_update_topdown_event() as well. The
function can be reused by the following patch.
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1611873611-156687-4-git-send-email-kan.liang@linux.intel.com
Similar to Ice Lake, Intel Sapphire Rapids server also supports the
topdown performance metrics feature. The difference is that Intel
Sapphire Rapids server extends the PERF_METRICS MSR to feature TMA
method level two metrics, which will introduce 8 metrics events. Current
icl_update_topdown_event() only check 4 level one metrics events.
Factor out intel_update_topdown_event() to facilitate the code sharing
between Ice Lake and Sapphire Rapids.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1611873611-156687-3-git-send-email-kan.liang@linux.intel.com
Current PERF_SAMPLE_WEIGHT sample type is very useful to expresses the
cost of an action represented by the sample. This allows the profiler
to scale the samples to be more informative to the programmer. It could
also help to locate a hotspot, e.g., when profiling by memory latencies,
the expensive load appear higher up in the histograms. But current
PERF_SAMPLE_WEIGHT sample type is solely determined by one factor. This
could be a problem, if users want two or more factors to contribute to
the weight. For example, Golden Cove core PMU can provide both the
instruction latency and the cache Latency information as factors for the
memory profiling.
For current X86 platforms, although meminfo::latency is defined as a
u64, only the lower 32 bits include the valid data in practice (No
memory access could last than 4G cycles). The higher 32 bits can be used
to store new factors.
Add a new sample type, PERF_SAMPLE_WEIGHT_STRUCT, to indicate the new
sample weight structure. It shares the same space as the
PERF_SAMPLE_WEIGHT sample type.
Users can apply either the PERF_SAMPLE_WEIGHT sample type or the
PERF_SAMPLE_WEIGHT_STRUCT sample type to retrieve the sample weight, but
they cannot apply both sample types simultaneously.
Currently, only X86 and PowerPC use the PERF_SAMPLE_WEIGHT sample type.
- For PowerPC, there is nothing changed for the PERF_SAMPLE_WEIGHT
sample type. There is no effect for the new PERF_SAMPLE_WEIGHT_STRUCT
sample type. PowerPC can re-struct the weight field similarly later.
- For X86, the same value will be dumped for the PERF_SAMPLE_WEIGHT
sample type or the PERF_SAMPLE_WEIGHT_STRUCT sample type for now.
The following patches will apply the new factors for the
PERF_SAMPLE_WEIGHT_STRUCT sample type.
The field in the union perf_sample_weight should be shared among
different architectures. A generic name is required, but it's hard to
abstract a name that applies to all architectures. For example, on X86,
the fields are to store all kinds of latency. While on PowerPC, it
stores MMCRA[TECX/TECM], which should not be latency. So a general name
prefix 'var$NUM' is used here.
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1611873611-156687-2-git-send-email-kan.liang@linux.intel.com
Perfmon-v4 counter freezing is fundamentally broken; remove this default
disabled code to make sure nobody uses it.
The feature is called Freeze-on-PMI in the SDM, and if it would do that,
there wouldn't actually be a problem, *however* it does something subtly
different. It globally disables the whole PMU when it raises the PMI,
not when the PMI hits.
This means there's a window between the PMI getting raised and the PMI
actually getting served where we loose events and this violates the
perf counter independence. That is, a counting event should not result
in a different event count when there is a sampling event co-scheduled.
This is known to break existing software (RR).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Clean up that CONFIG_RETPOLINE crud and replace the
indirect call x86_pmu.guest_get_msrs with static_call().
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210125121458.181635-1-like.xu@linux.intel.com
The registers used to determine which die a pci bus belongs to don't
contain enough information to uniquely specify more than 8 dies, so
when more than 8 dies are present, use NUMA information instead.
Continue to use the previous method for 8 or fewer because it
works there, and covers cases of NUMA being disabled.
Signed-off-by: Steve Wahl <steve.wahl@hpe.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lkml.kernel.org/r/20210108153549.108989-3-steve.wahl@hpe.com
The phys_id isn't really used other than to map to a logical die id.
Calculate the logical die id earlier, and store that instead of the
phys_id.
Signed-off-by: Steve Wahl <steve.wahl@hpe.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lkml.kernel.org/r/20210108153549.108989-2-steve.wahl@hpe.com
Core:
- Better handling of page table leaves on archictectures which have
architectures have non-pagetable aligned huge/large pages. For such
architectures a leaf can actually be part of a larger entry.
- Prevent a deadlock vs. exec_update_mutex
Architectures:
- The related updates for page size calculation of leaf entries
- The usual churn to support new CPUs
- Small fixes and improvements all over the place
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Merge tag 'perf-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Thomas Gleixner:
"Core:
- Better handling of page table leaves on archictectures which have
architectures have non-pagetable aligned huge/large pages. For such
architectures a leaf can actually be part of a larger entry.
- Prevent a deadlock vs exec_update_mutex
Architectures:
- The related updates for page size calculation of leaf entries
- The usual churn to support new CPUs
- Small fixes and improvements all over the place"
* tag 'perf-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
perf/x86/intel: Add Tremont Topdown support
uprobes/x86: Fix fall-through warnings for Clang
perf/x86: Fix fall-through warnings for Clang
kprobes/x86: Fix fall-through warnings for Clang
perf/x86/intel/lbr: Fix the return type of get_lbr_cycles()
perf/x86/intel: Fix rtm_abort_event encoding on Ice Lake
x86/kprobes: Restore BTF if the single-stepping is cancelled
perf: Break deadlock involving exec_update_mutex
sparc64/mm: Implement pXX_leaf_size() support
powerpc/8xx: Implement pXX_leaf_size() support
arm64/mm: Implement pXX_leaf_size() support
perf/core: Fix arch_perf_get_page_size()
mm: Introduce pXX_leaf_size()
mm/gup: Provide gup_get_pte() more generic
perf/x86/intel: Add event constraint for CYCLE_ACTIVITY.STALLS_MEM_ANY
perf/x86/intel/uncore: Add Rocket Lake support
perf/x86/msr: Add Rocket Lake CPU support
perf/x86/cstate: Add Rocket Lake CPU support
perf/x86/intel: Add Rocket Lake CPU support
perf,mm: Handle non-page-table-aligned hugetlbfs
...
(Gabriel Krisman Bertazi)
- All kinds of minor cleanups all over the tree.
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Merge tag 'x86_cleanups_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Borislav Petkov:
"Another branch with a nicely negative diffstat, just the way I
like 'em:
- Remove all uses of TIF_IA32 and TIF_X32 and reclaim the two bits in
the end (Gabriel Krisman Bertazi)
- All kinds of minor cleanups all over the tree"
* tag 'x86_cleanups_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
x86/ia32_signal: Propagate __user annotation properly
x86/alternative: Update text_poke_bp() kernel-doc comment
x86/PCI: Make a kernel-doc comment a normal one
x86/asm: Drop unused RDPID macro
x86/boot/compressed/64: Use TEST %reg,%reg instead of CMP $0,%reg
x86/head64: Remove duplicate include
x86/mm: Declare 'start' variable where it is used
x86/head/64: Remove unused GET_CR2_INTO() macro
x86/boot: Remove unused finalize_identity_maps()
x86/uaccess: Document copy_from_user_nmi()
x86/dumpstack: Make show_trace_log_lvl() static
x86/mtrr: Fix a kernel-doc markup
x86/setup: Remove unused MCA variables
x86, libnvdimm/test: Remove COPY_MC_TEST
x86: Reclaim TIF_IA32 and TIF_X32
x86/mm: Convert mmu context ia32_compat into a proper flags field
x86/elf: Use e_machine to check for x32/ia32 in setup_additional_pages()
elf: Expose ELF header on arch_setup_additional_pages()
x86/elf: Use e_machine to select start_thread for x32
elf: Expose ELF header in compat_start_thread()
...
Tremont has four L1 Topdown events, TOPDOWN_FE_BOUND.ALL,
TOPDOWN_BAD_SPECULATION.ALL, TOPDOWN_BE_BOUND.ALL and
TOPDOWN_RETIRING.ALL. They are available on GP counters.
Export them to sysfs and facilitate the perf stat tool.
$perf stat --topdown -- sleep 1
Performance counter stats for 'sleep 1':
retiring bad speculation frontend bound
backend bound
24.9% 16.8% 31.7%
26.6%
1.001224610 seconds time elapsed
0.001150000 seconds user
0.000000000 seconds sys
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1607457952-3519-1-git-send-email-kan.liang@linux.intel.com
The cycle count of a timed LBR is always 1 in perf record -D.
The cycle count is stored in the first 16 bits of the IA32_LBR_x_INFO
register, but the get_lbr_cycles() return Boolean type.
Use u16 to replace the Boolean type.
Fixes: 47125db27e ("perf/x86/intel/lbr: Support Architectural LBR")
Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20201125213720.15692-2-kan.liang@linux.intel.com
According to the event list from icelake_core_v1.09.json, the encoding
of the RTM_RETIRED.ABORTED event on Ice Lake should be,
"EventCode": "0xc9",
"UMask": "0x04",
"EventName": "RTM_RETIRED.ABORTED",
Correct the wrong encoding.
Fixes: 6017608936 ("perf/x86/intel: Add Icelake support")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20201125213720.15692-1-kan.liang@linux.intel.com
The kernel cannot disambiguate when 2+ PEBS counters overflow at the
same time. This is what the comment for this code suggests. However,
I see the comparison is done with the unfiltered p->status which is a
copy of IA32_PERF_GLOBAL_STATUS at the time of the sample. This
register contains more than the PEBS counter overflow bits. It also
includes many other bits which could also be set.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201126110922.317681-2-namhyung@kernel.org
The commit 3966c3feca ("x86/perf/amd: Remove need to check "running"
bit in NMI handler") introduced this. It seems x86_pmu_stop can be
called recursively (like when it losts some samples) like below:
x86_pmu_stop
intel_pmu_disable_event (x86_pmu_disable)
intel_pmu_pebs_disable
intel_pmu_drain_pebs_nhm (x86_pmu_drain_pebs_buffer)
x86_pmu_stop
While commit 35d1ce6bec ("perf/x86/intel/ds: Fix x86_pmu_stop
warning for large PEBS") fixed it for the normal cases, there's
another path to call x86_pmu_stop() recursively when a PEBS error was
detected (like two or more counters overflowed at the same time).
Like in the Kan's previous fix, we can skip the interrupt accounting
for large PEBS, so check the iregs which is set for PMI only.
Fixes: 3966c3feca ("x86/perf/amd: Remove need to check "running" bit in NMI handler")
Reported-by: John Sperbeck <jsperbeck@google.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201126110922.317681-1-namhyung@kernel.org
This change switches rapl to use PMU_FORMAT_ATTR, and fixes two other
macros to use device_attribute instead of kobj_attribute to avoid
callback type mismatches that trip indirect call checking with Clang's
Control-Flow Integrity (CFI).
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20201113183126.1239404-1-samitolvanen@google.com
gcc -Wextra points out a duplicate initialization of one array
member:
arch/x86/events/intel/uncore_snb.c:478:37: warning: initialized field overwritten [-Woverride-init]
478 | [SNB_PCI_UNCORE_IMC_DATA_READS] = { SNB_UNCORE_PCI_IMC_DATA_WRITES_BASE,
The only sensible explanation is that a duplicate 'READS' was used
instead of the correct 'WRITES', so change it back.
Fixes: 24633d901e ("perf/x86/intel/uncore: Add BW counters for GT, IA and IO breakdown")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201026215203.3893972-1-arnd@kernel.org
Starting with Arch Perfmon v5, the anythread filter on generic counters may be
deprecated. The current kernel was exporting the any filter without checking.
On Icelake, it means you could do cpu/event=0x3c,any/ even though the filter
does not exist. This patch corrects the problem by relying on the CPUID 0xa leaf
function to determine if anythread is supported or not as described in the
Intel SDM Vol3b 18.2.5.1 AnyThread Deprecation section.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201028194247.3160610-1-eranian@google.com
Having pt_regs on-stack is unfortunate, it's 168 bytes. Since it isn't
actually used, make it a static variable. This both gets if off the
stack and ensures it gets 0 initialized, just in case someone does
look at it.
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201030151955.324273677@infradead.org
intel_pmu_drain_pebs_*() is typically called from handle_pmi_common(),
both have an on-stack struct perf_sample_data, which is *big*. Rewire
things so that drain_pebs() can use the one handle_pmi_common() has.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201030151955.054099690@infradead.org
__perf_output_begin() has an on-stack struct perf_sample_data in the
unlikely case it needs to generate a LOST record. However, every call
to perf_output_begin() must already have a perf_sample_data on-stack.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201030151954.985416146@infradead.org
The event CYCLE_ACTIVITY.STALLS_MEM_ANY (0x14a3) should be available on
all 8 GP counters on ICL, but it's only scheduled on the first four
counters due to the current ICL constraint table.
Add a line for the CYCLE_ACTIVITY.STALLS_MEM_ANY event in the ICL
constraint table.
Correct the comments for the CYCLE_ACTIVITY.CYCLES_MEM_ANY event.
Fixes: 6017608936 ("perf/x86/intel: Add Icelake support")
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20201019164529.32154-1-kan.liang@linux.intel.com
For Rocket Lake, the MSR uncore, e.g., CBOX, ARB and CLOCKBOX, are the
same as Tiger Lake. Share the perf code with it.
For Rocket Lake and Tiger Lake, the 8th CBOX is not mapped into a
different MSR space anymore. Add rkl_uncore_msr_init_box() to replace
skl_uncore_msr_init_box().
The IMC uncore is the similar to Ice Lake. Add new PCIIDs of IMC for
Rocket Lake.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201019153528.13850-4-kan.liang@linux.intel.com
From the perspective of Intel cstate residency counters, Rocket Lake is
the same as Ice Lake and Tiger Lake. Share the code with them. Update
the comments for Rocket Lake.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201019153528.13850-2-kan.liang@linux.intel.com
From the perspective of Intel PMU, Rocket Lake is the same as Ice Lake
and Tiger Lake. Share the perf code with them.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201019153528.13850-1-kan.liang@linux.intel.com
The new sample type, PERF_SAMPLE_DATA_PAGE_SIZE, requires the virtual
address. Update the data->addr if the sample type is set.
The large PEBS is disabled with the sample type, because perf doesn't
support munmap tracking yet. The PEBS buffer for large PEBS cannot be
flushed for each munmap. Wrong page size may be calculated. The large
PEBS can be enabled later separately when munmap tracking is supported.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201001135749.2804-3-kan.liang@linux.intel.com
In preparation to remove TIF_IA32, stop using it in perf events code.
Tested by running perf on 32-bit, 64-bit and x32 applications.
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20201004032536.1229030-2-krisman@collabora.com
x86 Intel updates:
- Add Jasper Lake support
- Add support for TopDown metrics on Ice Lake
- Fix Ice Lake & Tiger Lake uncore support, add Snow Ridge support
- Add a PCI sub driver to support uncore PMUs where the PCI resources
have been claimed already - extending the range of supported systems.
x86 AMD updates:
- Restore 'perf stat -a' behaviour to program the uncore PMU
to count all CPU threads.
- Fix setting the proper count when sampling Large Increment
per Cycle events / 'paired' events.
- Fix IBS Fetch sampling on F17h and some other IBS fine tuning,
greatly reducing the number of interrupts when large sample
periods are specified.
- Extends Family 17h RAPL support to also work on compatible
F19h machines.
Core code updates:
- Fix race in perf_mmap_close()
- Add PERF_EV_CAP_SIBLING, to denote that sibling events should be
closed if the leader is removed.
- Smaller fixes and updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull performance events updates from Ingo Molnar:
"x86 Intel updates:
- Add Jasper Lake support
- Add support for TopDown metrics on Ice Lake
- Fix Ice Lake & Tiger Lake uncore support, add Snow Ridge support
- Add a PCI sub driver to support uncore PMUs where the PCI resources
have been claimed already - extending the range of supported
systems.
x86 AMD updates:
- Restore 'perf stat -a' behaviour to program the uncore PMU to count
all CPU threads.
- Fix setting the proper count when sampling Large Increment per
Cycle events / 'paired' events.
- Fix IBS Fetch sampling on F17h and some other IBS fine tuning,
greatly reducing the number of interrupts when large sample periods
are specified.
- Extends Family 17h RAPL support to also work on compatible F19h
machines.
Core code updates:
- Fix race in perf_mmap_close()
- Add PERF_EV_CAP_SIBLING, to denote that sibling events should be
closed if the leader is removed.
- Smaller fixes and updates"
* tag 'perf-core-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits)
perf/core: Fix race in the perf_mmap_close() function
perf/x86: Fix n_metric for cancelled txn
perf/x86: Fix n_pair for cancelled txn
x86/events/amd/iommu: Fix sizeof mismatch
perf/x86/intel: Check perf metrics feature for each CPU
perf/x86/intel: Fix Ice Lake event constraint table
perf/x86/intel/uncore: Fix the scale of the IMC free-running events
perf/x86/intel/uncore: Fix for iio mapping on Skylake Server
perf/x86/msr: Add Jasper Lake support
perf/x86/intel: Add Jasper Lake support
perf/x86/intel/uncore: Reduce the number of CBOX counters
perf/x86/intel/uncore: Update Ice Lake uncore units
perf/x86/intel/uncore: Split the Ice Lake and Tiger Lake MSR uncore support
perf/x86/intel/uncore: Support PCIe3 unit on Snow Ridge
perf/x86/intel/uncore: Generic support for the PCI sub driver
perf/x86/intel/uncore: Factor out uncore_pci_pmu_unregister()
perf/x86/intel/uncore: Factor out uncore_pci_pmu_register()
perf/x86/intel/uncore: Factor out uncore_pci_find_dev_pmu()
perf/x86/intel/uncore: Factor out uncore_pci_get_dev_die_info()
perf/amd/uncore: Inform the user how many counters each uncore PMU has
...
It might be possible that different CPUs have different CPU metrics on a
platform. In this case, writing the GLOBAL_CTRL_EN_PERF_METRICS bit to
the GLOBAL_CTRL register of a CPU, which doesn't support the TopDown
perf metrics feature, causes MSR access error.
Current TopDown perf metrics feature is enumerated using the boot CPU's
PERF_CAPABILITIES MSR. The MSR only indicates the boot CPU supports this
feature.
Check the PERF_CAPABILITIES MSR for each CPU. If any CPU doesn't support
the perf metrics feature, disable the feature globally.
Fixes: 59a854e2f3 ("perf/x86/intel: Support TopDown metrics on Ice Lake")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201001211711.25708-1-kan.liang@linux.intel.com
An error occues when sampling non-PEBS INST_RETIRED.PREC_DIST(0x01c0)
event.
perf record -e cpu/event=0xc0,umask=0x01/ -- sleep 1
Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument)
for event (cpu/event=0xc0,umask=0x01/).
/bin/dmesg | grep -i perf may provide additional information.
The idxmsk64 of the event is set to 0. The event never be successfully
scheduled.
The event should be limit to the fixed counter 0.
Fixes: 6017608936 ("perf/x86/intel: Add Icelake support")
Reported-by: Yi, Ammy <ammy.yi@intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200928134726.13090-1-kan.liang@linux.intel.com
The "MiB" result of the IMC free-running bandwidth events,
uncore_imc_free_running/read/ and uncore_imc_free_running/write/ are 16
times too small.
The "MiB" value equals the raw IMC free-running bandwidth counter value
times a "scale" which is inaccurate.
The IMC free-running bandwidth events should be incremented per 64B
cache line, not DWs (4 bytes). The "scale" should be 6.103515625e-5.
Fix the "scale" for both Snow Ridge and Ice Lake.
Fixes: 2b3b76b5ec ("perf/x86/intel/uncore: Add Ice Lake server uncore support")
Fixes: ee49532b38 ("perf/x86/intel/uncore: Add IMC uncore support for Snow Ridge")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200928133240.12977-1-kan.liang@linux.intel.com
Introduced early attributes /sys/devices/uncore_iio_<pmu_idx>/die* are
initialized by skx_iio_set_mapping(), however, for example, for multiple
segment platforms skx_iio_get_topology() returns -EPERM before a list of
attributes in skx_iio_mapping_group will have been initialized.
As a result the list is being NULL. Thus the warning
"sysfs: (bin_)attrs not set by subsystem for group: uncore_iio_*/" appears
and uncore_iio pmus are not available in sysfs. Clear IIO attr_update
to properly handle the cases when topology information cannot be
retrieved.
Fixes: bb42b3d397 ("perf/x86/intel/uncore: Expose an Uncore unit to IIO PMON mapping")
Reported-by: Kyle Meyer <kyle.meyer@hpe.com>
Suggested-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Alexander Antonov <alexander.antonov@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alexei Budankov <alexey.budankov@linux.intel.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lkml.kernel.org/r/20200928102133.61041-1-alexander.antonov@linux.intel.com
The Jasper Lake processor is also a Tremont microarchitecture. From the
perspective of Intel PMU, there is nothing changed compared with
Elkhart Lake.
Share the perf code with Elkhart Lake.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1601296242-32763-1-git-send-email-kan.liang@linux.intel.com
An oops is triggered by the fuzzy test.
[ 327.853081] unchecked MSR access error: RDMSR from 0x70c at rIP:
0xffffffffc082c820 (uncore_msr_read_counter+0x10/0x50 [intel_uncore])
[ 327.853083] Call Trace:
[ 327.853085] <IRQ>
[ 327.853089] uncore_pmu_event_start+0x85/0x170 [intel_uncore]
[ 327.853093] uncore_pmu_event_add+0x1a4/0x410 [intel_uncore]
[ 327.853097] ? event_sched_in.isra.118+0xca/0x240
There are 2 GP counters for each CBOX, but the current code claims 4
counters. Accessing the invalid registers triggers the oops.
Fixes: 6e394376ee ("perf/x86/intel/uncore: Add Intel Icelake uncore support")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200925134905.8839-3-kan.liang@linux.intel.com
There are some updates for the Icelake model specific uncore performance
monitors. (The update can be found at 10th generation intel core
processors families specification update Revision 004, ICL068)
1) Counter 0 of ARB uncore unit is not available for software use
2) The global 'enable bit' (bit 29) and 'freeze bit' (bit 31) of
MSR_UNC_PERF_GLOBAL_CTRL cannot be used to control counter behavior.
Needs to use local enable in event select MSR.
Accessing the modified bit/registers will be ignored by HW. Users may
observe inaccurate results with the current code.
The changes of the MSR_UNC_PERF_GLOBAL_CTRL imply that groups cannot be
read atomically anymore. Although the error of the result for a group
becomes a bit bigger, it still far lower than not using a group. The
group support is still kept. Only Remove the *_box() related
implementation.
Since the counter 0 of ARB uncore unit is not available, update the MSR
address for the ARB uncore unit.
There is no change for IMC uncore unit, which only include free-running
counters.
Fixes: 6e394376ee ("perf/x86/intel/uncore: Add Intel Icelake uncore support")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200925134905.8839-2-kan.liang@linux.intel.com
Previously, the MSR uncore for the Ice Lake and Tiger Lake are
identical. The code path is shared. However, with recent update, the
global MSR_UNC_PERF_GLOBAL_CTRL register and ARB uncore unit are changed
for the Ice Lake. Split the Ice Lake and Tiger Lake MSR uncore support.
The changes only impact the MSR ops() and the ARB uncore unit. Other
codes can still be shared between the Ice Lake and the Tiger Lake.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200925134905.8839-1-kan.liang@linux.intel.com
The Snow Ridge integrated PCIe3 uncore unit can be used to collect
performance data, e.g. utilization, between PCIe devices, plugged into
the PCIe port, and the components (in M2IOSF) responsible for
translating and managing requests to/from the device. The performance
data is very useful for analyzing the performance of PCIe devices.
The device with the PCIe3 uncore PMON units is owned by the portdrv_pci
driver. Create a PCI sub driver for the PCIe3 uncore PMON units.
Here are some difference between PCIe3 uncore unit and other uncore
pci units.
- There may be several Root Ports on a system. But the uncore counters
only exist in the Root Port A. A user can configure the channel mask
to collect the data from other Root Ports.
- The event format of the PCIe3 uncore unit is the same as IIO unit of
SKX.
- The Control Register of PCIe3 uncore unit is 64 bits.
- The offset of each counters is 8, which is the same as M2M unit of
SNR.
- New MSR addresses for unit control, counter and counter config.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1600094060-82746-7-git-send-email-kan.liang@linux.intel.com
Some uncore counters may be located in the configuration space of a PCI
device, which already has a bonded driver. Currently, the uncore driver
cannot register a PCI uncore PMU for these counters, because, to
register a PCI uncore PMU, the uncore driver must be bond to the device.
However, one device can only have one bonded driver.
Add an uncore PCI sub driver to support such kind of devices.
The sub driver doesn't own the device. In initialization, the sub
driver searches the device via pci_get_device(), and register the
corresponding PMU for the device. In the meantime, the sub driver
registers a PCI bus notifier, which is used to notify the sub driver
once the device is removed. The sub driver can unregister the PMU
accordingly.
The sub driver only searches the devices defined in its id table. The
id table varies on different platforms, which will be implemented in the
following platform-specific patch.
Suggested-by: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1600094060-82746-6-git-send-email-kan.liang@linux.intel.com
The PMU unregistration in the uncore PCI sub driver is similar as the
normal PMU unregistration for a PCI device. The codes to unregister a
PCI PMU can be shared.
Factor out uncore_pci_pmu_unregister(), which will be used later.
Use uncore_pci_get_dev_die_info() to replace the codes which retrieve
the socket and die informaion.
The pci_set_drvdata() is not included in uncore_pci_pmu_unregister() as
well, because the uncore PCI sub driver will not touch the private
driver data pointer of the device.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1600094060-82746-5-git-send-email-kan.liang@linux.intel.com
The PMU registration in the uncore PCI sub driver is similar as the
normal PMU registration for a PCI device. The codes to register a PCI
PMU can be shared.
Factor out uncore_pci_pmu_register(), which will be used later.
The pci_set_drvdata() is not included in uncore_pci_pmu_register(). The
uncore PCI sub driver doesn't own the PCI device. It will not touch the
private driver data pointer for the device.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1600094060-82746-4-git-send-email-kan.liang@linux.intel.com
When an uncore PCI sub driver gets a remove notification, the
corresponding PMU has to be retrieved and unregistered. The codes, which
find the corresponding PMU by comparing the pci_device_id table, can be
shared.
Factor out uncore_pci_find_dev_pmu(), which will be used later.
There is no functional change.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1600094060-82746-3-git-send-email-kan.liang@linux.intel.com
The socket and die information is required to register/unregister a PMU
in the uncore PCI sub driver. The codes, which get the socket and die
information from a BUS number, can be shared.
Factor out uncore_pci_get_dev_die_info(), which will be used later.
There is no functional change.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1600094060-82746-2-git-send-email-kan.liang@linux.intel.com
A warning as below may be triggered when sampling with large PEBS.
[ 410.411250] perf: interrupt took too long (72145 > 71975), lowering
kernel.perf_event_max_sample_rate to 2000
[ 410.724923] ------------[ cut here ]------------
[ 410.729822] WARNING: CPU: 0 PID: 16397 at arch/x86/events/core.c:1422
x86_pmu_stop+0x95/0xa0
[ 410.933811] x86_pmu_del+0x50/0x150
[ 410.937304] event_sched_out.isra.0+0xbc/0x210
[ 410.941751] group_sched_out.part.0+0x53/0xd0
[ 410.946111] ctx_sched_out+0x193/0x270
[ 410.949862] __perf_event_task_sched_out+0x32c/0x890
[ 410.954827] ? set_next_entity+0x98/0x2d0
[ 410.958841] __schedule+0x592/0x9c0
[ 410.962332] schedule+0x5f/0xd0
[ 410.965477] exit_to_usermode_loop+0x73/0x120
[ 410.969837] prepare_exit_to_usermode+0xcd/0xf0
[ 410.974369] ret_from_intr+0x2a/0x3a
[ 410.977946] RIP: 0033:0x40123c
[ 411.079661] ---[ end trace bc83adaea7bb664a ]---
In the non-overflow context, e.g., context switch, with large PEBS, perf
may stop an event twice. An example is below.
//max_samples_per_tick is adjusted to 2
//NMI is triggered
intel_pmu_handle_irq()
handle_pmi_common()
drain_pebs()
__intel_pmu_pebs_event()
perf_event_overflow()
__perf_event_account_interrupt()
hwc->interrupts = 1
return 0
//A context switch happens right after the NMI.
//In the same tick, the perf_throttled_seq is not changed.
perf_event_task_sched_out()
perf_pmu_sched_task()
intel_pmu_drain_pebs_buffer()
__intel_pmu_pebs_event()
perf_event_overflow()
__perf_event_account_interrupt()
++hwc->interrupts >= max_samples_per_tick
return 1
x86_pmu_stop(); # First stop
perf_event_context_sched_out()
task_ctx_sched_out()
ctx_sched_out()
event_sched_out()
x86_pmu_del()
x86_pmu_stop(); # Second stop and trigger the warning
Perf should only invoke the perf_event_overflow() in the overflow
context.
Current drain_pebs() is called from:
- handle_pmi_common() -- overflow context
- intel_pmu_pebs_sched_task() -- non-overflow context
- intel_pmu_pebs_disable() -- non-overflow context
- intel_pmu_auto_reload_read() -- possible overflow context
With PERF_SAMPLE_READ + PERF_FORMAT_GROUP, the function may be
invoked in the NMI handler. But, before calling the function, the
PEBS buffer has already been drained. The __intel_pmu_pebs_event()
will not be called in the possible overflow context.
To fix the issue, an indicator is required to distinguish between the
overflow context aka handle_pmi_common() and other cases.
The dummy regs pointer can be used as the indicator.
In the non-overflow context, perf should treat the last record the same
as other PEBS records, and doesn't invoke the generic overflow handler.
Fixes: 21509084f9 ("perf/x86/intel: Handle multiple records in the PEBS buffer")
Reported-by: Like Xu <like.xu@linux.intel.com>
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Like Xu <like.xu@linux.intel.com>
Link: https://lkml.kernel.org/r/20200902210649.2743-1-kan.liang@linux.intel.com
Starts from Ice Lake, the TopDown metrics are directly available as
fixed counters and do not require generic counters. Also, the TopDown
metrics can be collected per thread. Extend the RDPMC usage to support
per-thread TopDown metrics.
The RDPMC index of the PERF_METRICS will be output if RDPMC users ask
for the RDPMC index of the metrics events.
To support per thread RDPMC TopDown, the metrics and slots counters have
to be saved/restored during the context switching.
The last_period and period_left are not used in the counting mode. Use
the fields for saved_metric and saved_slots.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200723171117.9918-12-kan.liang@linux.intel.com
Ice Lake supports the hardware TopDown metrics feature, which can free
up the scarce GP counters.
Update the event constraints for the metrics events. The metric counters
do not exist, which are mapped to a dummy offset. The sharing between
multiple users of the same metric without multiplexing is not allowed.
Implement set_topdown_event_period for Ice Lake. The values in
PERF_METRICS MSR are derived from the fixed counter 3. Both registers
should start from zero.
Implement update_topdown_event for Ice Lake. The metric is reported by
multiplying the metric (fraction) with slots. To maintain accurate
measurements, both registers are cleared for each update. The fixed
counter 3 should always be cleared before the PERF_METRICS.
Implement td_attr for the new metrics events and the new slots fixed
counter. Make them visible to the perf user tools.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200723171117.9918-11-kan.liang@linux.intel.com
Intro
=====
The TopDown Microarchitecture Analysis (TMA) Method is a structured
analysis methodology to identify critical performance bottlenecks in
out-of-order processors. Current perf has supported the method.
The method works well, but there is one problem. To collect the TopDown
events, several GP counters have to be used. If a user wants to collect
other events at the same time, the multiplexing probably be triggered,
which impacts the accuracy.
To free up the scarce GP counters, the hardware TopDown metrics feature
is introduced from Ice Lake. The hardware implements an additional
"metrics" register and a new Fixed Counter 3 that measures pipeline
"slots". The TopDown events can be calculated from them instead.
Events
======
The level 1 TopDown has four metrics. There is no event-code assigned to
the TopDown metrics. Four metric events are exported as separate perf
events, which map to the internal "metrics" counter register. Those
events do not exist in hardware, but can be allocated by the scheduler.
For the event mapping, a special 0x00 event code is used, which is
reserved for fake events. The metric events start from umask 0x10.
When setting up the metric events, they point to the Fixed Counter 3.
They have to be specially handled.
- Add the update_topdown_event() callback to read the additional metrics
MSR and generate the metrics.
- Add the set_topdown_event_period() callback to initialize metrics MSR
and the fixed counter 3.
- Add a variable n_metric_event to track the number of the accepted
metrics events. The sharing between multiple users of the same metric
without multiplexing is not allowed.
- Only enable/disable the fixed counter 3 when there are no other active
TopDown events, which avoid the unnecessary writing of the fixed
control register.
- Disable the PMU when reading the metrics event. The metrics MSR and
the fixed counter 3 are read separately. The values may be modified by
an NMI.
All four metric events don't support sampling. Since they will be
handled specially for event update, a flag PERF_X86_EVENT_TOPDOWN is
introduced to indicate this case.
The slots event can support both sampling and counting.
For counting, the flag is also applied.
For sampling, it will be handled normally as other normal events.
Groups
======
The slots event is required in a Topdown group.
To avoid reading the METRICS register multiple times, the metrics and
slots value can only be updated by slots event in a group.
All active slots and metrics events will be updated one time.
Therefore, the slots event must be before any metric events in a Topdown
group.
NMI
======
The METRICS related register may be overflow. The bit 48 of the STATUS
register will be set. If so, PERF_METRICS and Fixed counter 3 are
required to be reset. The patch also update all active slots and
metrics events in the NMI handler.
The update_topdown_event() has to read two registers separately. The
values may be modified by an NMI. PMU has to be disabled before calling
the function.
RDPMC
======
RDPMC is temporarily disabled. A later patch will enable it.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200723171117.9918-9-kan.liang@linux.intel.com
