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Teach objtool a little more about IRET so that we can avoid using the
SAVE/RESTORE annotation. In particular, make the weird corner case in
insn->restore go away.
The purpose of that corner case is to deal with the fact that
UNWIND_HINT_RESTORE lands on the instruction after IRET, but that
instruction can end up being outside the basic block, consider:
if (cond)
sync_core()
foo();
Then the hint will land on foo(), and we'll encounter the restore
hint without ever having seen the save hint.
By teaching objtool about the arch specific exception frame size, and
assuming that any IRET in an STT_FUNC symbol is an exception frame
sized POP, we can remove the use of save/restore hints for this code.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200416115118.631224674@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Instruction sets can include more or less complex operations which might
not fit the currently defined set of stack_ops.
Combining more than one stack_op provides more flexibility to describe
the behaviour of an instruction. This also reduces the need to define
new stack_ops specific to a single instruction set.
Allow instruction decoders to generate multiple stack_op per
instruction.
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200327152847.15294-11-jthierry@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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If the prefix of section name is not '.rodata', the following
function call can never return 0.
strcmp(sec->name, C_JUMP_TABLE_SECTION)
So the name comparison is pointless, just remove it.
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Compiling with Clang and CONFIG_KASAN=y was exposing a few warnings:
call to memset() with UACCESS enabled
Document how to fix these for future travelers.
Link: https://github.com/ClangBuiltLinux/linux/issues/876
Suggested-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Suggested-by: Matt Helsley <mhelsley@vmware.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Some CFI definitions used by generic objtool code have no reason to vary
from one architecture to another. Keep those definitions in generic
code and move the arch-specific ones to a new arch-specific header.
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The jump and call destination relocation offsets are x86-specific.
Abstract them by calling arch-specific implementations.
[ jthierry: Remove superfluous comment; replace other addend offsets
with arch_dest_rela_offset() ]
Signed-off-by: Raphael Gault <raphael.gault@arm.com>
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The initial register state is set up by arch specific code. Use the
value the arch code has set when restoring registers from the stack.
Suggested-by: Raphael Gault <raphael.gault@arm.com>
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The .alternatives section can contain entries with no original
instructions. Objtool will currently crash when handling such an entry.
Just skip that entry, but still give a warning to discourage useless
entries.
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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When a function fails its validation, it might leave a stale state
that will be used for the validation of other functions. That would
cause false warnings on potentially valid functions.
Reset the instruction state before the validation of each individual
function.
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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POP operations are already in the code path where the destination
operand is OP_DEST_REG. There is no need to check the operand type
again.
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Currently, the check of tools files against kernel equivalent is only
done after every object file has been built. This means one might fix
build issues against outdated headers without seeing a warning about
this.
Check headers before any object is built. Also, make it part of a
FORCE'd recipe so every attempt to build objtool will report the
outdated headers (if any).
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Sometimes, WARN_FUNC() and other users of symbol_by_offset() will
associate the first instruction of a symbol with the symbol preceding
it. This is because symbol->offset + symbol->len is already outside of
the symbol's range.
Fixes: 2a362ecc3ec9 ("objtool: Optimize find_symbol_*() and read_symbols()")
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Apparently there's people doing 64bit builds on 32bit machines.
Fixes: 74b873e49d92 ("objtool: Optimize find_rela_by_dest_range()")
Reported-by: youling257@gmail.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge misc fixes from Andrew Morton:
"15 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
tools/vm: fix cross-compile build
coredump: fix null pointer dereference on coredump
mm: shmem: disable interrupt when acquiring info->lock in userfaultfd_copy path
shmem: fix possible deadlocks on shmlock_user_lock
vmalloc: fix remap_vmalloc_range() bounds checks
mm/shmem: fix build without THP
mm/ksm: fix NULL pointer dereference when KSM zero page is enabled
tools/build: tweak unused value workaround
checkpatch: fix a typo in the regex for $allocFunctions
mm, gup: return EINTR when gup is interrupted by fatal signals
mm/hugetlb: fix a addressing exception caused by huge_pte_offset
MAINTAINERS: add an entry for kfifo
mm/userfaultfd: disable userfaultfd-wp on x86_32
slub: avoid redzone when choosing freepointer location
sh: fix build error in mm/init.c
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Pull virtio fixes and cleanups from Michael Tsirkin:
- Some bug fixes
- Cleanup a couple of issues that surfaced meanwhile
- Disable vhost on ARM with OABI for now - to be fixed fully later in
the cycle or in the next release.
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (24 commits)
vhost: disable for OABI
virtio: drop vringh.h dependency
virtio_blk: add a missing include
virtio-balloon: Avoid using the word 'report' when referring to free page hinting
virtio-balloon: make virtballoon_free_page_report() static
vdpa: fix comment of vdpa_register_device()
vdpa: make vhost, virtio depend on menu
vdpa: allow a 32 bit vq alignment
drm/virtio: fix up for include file changes
remoteproc: pull in slab.h
rpmsg: pull in slab.h
virtio_input: pull in slab.h
remoteproc: pull in slab.h
virtio-rng: pull in slab.h
virtgpu: pull in uaccess.h
tools/virtio: make asm/barrier.h self contained
tools/virtio: define aligned attribute
virtio/test: fix up after IOTLB changes
vhost: Create accessors for virtqueues private_data
vdpasim: Return status in vdpasim_get_status
...
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Commit 7ed1c1901fe5 ("tools: fix cross-compile var clobbering") moved
the setup of the CC variable to tools/scripts/Makefile.include to make
the behavior consistent across all the tools Makefiles.
As the vm tools missed the include we end up with the wrong CC in a
cross-compiling evironment.
Fixes: 7ed1c1901fe5 (tools: fix cross-compile var clobbering)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Martin Kelly <martin@martingkelly.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200416104748.25243-1-l.stach@pengutronix.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Clang has -Wself-assign enabled by default under -Wall, which always
gets -Werror'ed on this file, causing sync-compare-and-swap to be
disabled by default.
The generally-accepted way to spell "this value is intentionally
unused," is casting it to `void`. This is accepted by both GCC and
Clang with -Wall enabled: https://godbolt.org/z/qqZ9r3
Signed-off-by: George Burgess IV <gbiv@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Link: http://lkml.kernel.org/r/20200414195638.156123-1-gbiv@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This file is close enough to being in rst format that I didn't feel
the need to alter it in any way.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Michel Lespinasse <walken@google.com>
Link: https://lore.kernel.org/r/20200401173343.17472-1-willy@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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This patch adds a test to test_verifier that writes the lower 8 bits of
R10 (aka FP) using BPF_B to an array map and reads the result back. The
expected behavior is that the result should be the same as first copying
R10 to R9, and then storing / loading the lower 8 bits of R9.
This test catches a bug that was present in the x86-64 JIT that caused
an incorrect encoding for BPF_STX BPF_B when the source operand is R10.
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200418232655.23870-2-luke.r.nels@gmail.com
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When check_xadd() verifies an XADD operation on a pointer to a stack slot
containing a spilled pointer, check_stack_read() verifies that the read,
which is part of XADD, is valid. However, since the placeholder value -1 is
passed as `value_regno`, check_stack_read() can only return a binary
decision and can't return the type of the value that was read. The intent
here is to verify whether the value read from the stack slot may be used as
a SCALAR_VALUE; but since check_stack_read() doesn't check the type, and
the type information is lost when check_stack_read() returns, this is not
enforced, and a malicious user can abuse XADD to leak spilled kernel
pointers.
Fix it by letting check_stack_read() verify that the value is usable as a
SCALAR_VALUE if no type information is passed to the caller.
To be able to use __is_pointer_value() in check_stack_read(), move it up.
Fix up the expected unprivileged error message for a BPF selftest that,
until now, assumed that unprivileged users can use XADD on stack-spilled
pointers. This also gives us a test for the behavior introduced in this
patch for free.
In theory, this could also be fixed by forbidding XADD on stack spills
entirely, since XADD is a locked operation (for operations on memory with
concurrency) and there can't be any concurrency on the BPF stack; but
Alexei has said that he wants to keep XADD on stack slots working to avoid
changes to the test suite [1].
The following BPF program demonstrates how to leak a BPF map pointer as an
unprivileged user using this bug:
// r7 = map_pointer
BPF_LD_MAP_FD(BPF_REG_7, small_map),
// r8 = launder(map_pointer)
BPF_STX_MEM(BPF_DW, BPF_REG_FP, BPF_REG_7, -8),
BPF_MOV64_IMM(BPF_REG_1, 0),
((struct bpf_insn) {
.code = BPF_STX | BPF_DW | BPF_XADD,
.dst_reg = BPF_REG_FP,
.src_reg = BPF_REG_1,
.off = -8
}),
BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_FP, -8),
// store r8 into map
BPF_MOV64_REG(BPF_REG_ARG1, BPF_REG_7),
BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -4),
BPF_ST_MEM(BPF_W, BPF_REG_ARG2, 0, 0),
BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
BPF_EXIT_INSN(),
BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_8, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN()
[1] https://lore.kernel.org/bpf/20200416211116.qxqcza5vo2ddnkdq@ast-mbp.dhcp.thefacebook.com/
Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200417000007.10734-1-jannh@google.com
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Some broken references happened due to shifting files around
and ReST renames. Those can't be auto-fixed by the script,
so let's fix them manually.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Link: https://lore.kernel.org/r/64773a12b4410aaf3e3be89e3ec7e34de2484eea.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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sleepgraph:
- force usage of python3 instead of using system default
- fix bugzilla 204773 (https://bugzilla.kernel.org/show_bug.cgi?id=204773)
- fix issue of platform info not being reset in -multi (logs fill up)
- change -ftop call to "pm_suspend", this is one level below state_store
- add -wificheck command to read out the current wifi device details
- change -wifi behavior to poll /proc/net/wireless for wifi connect
- add wifi reconnect time to timeline, include time in summary column
- add "fail on wifi_resume" to timeline and summary when wifi fails
- add a set of commands to collect data before/after suspend in the log
- add "-cmdinfo" command which prints out all the data collected
- check for cmd info tools at start, print found/missing in green/red
- fix kernel suspend time calculation: tool used to look for start of
pm_suspend_console, but the order has changed. latest kernel starts
with ksys_sync, use this instead
- include time spent in mem/disk in the header (same as freeze/standby)
- ignore turbostat 32-bit capability warnings
- print to result.txt when -skiphtml is used, just say result: pass
- don't exit on SIGTSTP, it's a ctrl-Z and the tool may come back
- -multi argument supports duration as well as count: hours, minutes, seconds
- update the -multi status output to be more informative
- -maxfail sets maximum consecutive fails before a -multi run is aborted
- in -summary, ignore dmesg/ftrace/html files that are 0 size
bootgraph:
- force usage of python3 instead of using system default
README:
- add endurance testing instructions
Makefile:
- remove pycache on uninstall
Signed-off-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 and objtool fixes from Thomas Gleixner:
"A set of fixes for x86 and objtool:
objtool:
- Ignore the double UD2 which is emitted in BUG() when
CONFIG_UBSAN_TRAP is enabled.
- Support clang non-section symbols in objtool ORC dump
- Fix switch table detection in .text.unlikely
- Make the BP scratch register warning more robust.
x86:
- Increase microcode maximum patch size for AMD to cope with new CPUs
which have a larger patch size.
- Fix a crash in the resource control filesystem when the removal of
the default resource group is attempted.
- Preserve Code and Data Prioritization enabled state accross CPU
hotplug.
- Update split lock cpu matching to use the new X86_MATCH macros.
- Change the split lock enumeration as Intel finaly decided that the
IA32_CORE_CAPABILITIES bits are not architectural contrary to what
the SDM claims. !@#%$^!
- Add Tremont CPU models to the split lock detection cpu match.
- Add a missing static attribute to make sparse happy"
* tag 'x86-urgent-2020-04-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/split_lock: Add Tremont family CPU models
x86/split_lock: Bits in IA32_CORE_CAPABILITIES are not architectural
x86/resctrl: Preserve CDP enable over CPU hotplug
x86/resctrl: Fix invalid attempt at removing the default resource group
x86/split_lock: Update to use X86_MATCH_INTEL_FAM6_MODEL()
x86/umip: Make umip_insns static
x86/microcode/AMD: Increase microcode PATCH_MAX_SIZE
objtool: Make BP scratch register warning more robust
objtool: Fix switch table detection in .text.unlikely
objtool: Support Clang non-section symbols in ORC generation
objtool: Support Clang non-section symbols in ORC dump
objtool: Fix CONFIG_UBSAN_TRAP unreachable warnings
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf tooling fixes and updates from Thomas Gleixner:
- Fix the header line of perf stat output for '--metric-only --per-socket'
- Fix the python build with clang
- The usual tools UAPI header synchronization
* tag 'perf-urgent-2020-04-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tools headers: Synchronize linux/bits.h with the kernel sources
tools headers: Adopt verbatim copy of compiletime_assert() from kernel sources
tools headers: Update x86's syscall_64.tbl with the kernel sources
tools headers UAPI: Sync drm/i915_drm.h with the kernel sources
tools headers UAPI: Update tools's copy of drm.h headers
tools headers kvm: Sync linux/kvm.h with the kernel sources
tools headers UAPI: Sync linux/fscrypt.h with the kernel sources
tools include UAPI: Sync linux/vhost.h with the kernel sources
tools arch x86: Sync asm/cpufeatures.h with the kernel sources
tools headers UAPI: Sync linux/mman.h with the kernel
tools headers UAPI: Sync sched.h with the kernel
tools headers: Update linux/vdso.h and grab a copy of vdso/const.h
perf stat: Fix no metric header if --per-socket and --metric-only set
perf python: Check if clang supports -fno-semantic-interposition
tools arch x86: Sync the msr-index.h copy with the kernel sources
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Perf checks the duplicate entries in a callchain before adding an entry.
However the check is very slow especially with deeper call stack.
Almost ~50% elapsed time of perf report is spent on the check when the
call stack is always depth of 32.
The hist_entry__cmp() is used to compare the new entry with the old
entries. It will go through all the available sorts in the sort_list,
and call the specific cmp of each sort, which is very slow.
Actually, for most cases, there are no duplicate entries in callchain.
The symbols are usually different. It's much faster to do a quick check
for symbols first. Only do the full cmp when the symbols are exactly the
same.
The quick check is only to check symbols, not dso. Export
_sort__sym_cmp.
$ perf record --call-graph lbr ./tchain_edit_64
Without the patch
$time perf report --stdio
real 0m21.142s
user 0m21.110s
sys 0m0.033s
With the patch
$time perf report --stdio
real 0m10.977s
user 0m10.948s
sys 0m0.027s
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-18-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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With the LBR stitching approach, the reconstructed LBR call stack can
break the HW limitation. However, it may reconstruct invalid call stacks
in some cases, e.g. exception handing such as setjmp/longjmp. Also, it
may impact the processing time especially when the number of samples
with stitched LBRs are huge.
Add an option to enable the approach.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-17-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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With the LBR stitching approach, the reconstructed LBR call stack
can break the HW limitation. However, it may reconstruct invalid call
stacks in some cases, e.g. exception handing such as setjmp/longjmp.
Also, it may impact the processing time especially when the number of
samples with stitched LBRs are huge.
Add an option to enable the approach.
The option must be used with --call-graph lbr.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-16-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
With the LBR stitching approach, the reconstructed LBR call stack can
break the HW limitation. However, it may reconstruct invalid call stacks
in some cases, e.g. exception handing such as setjmp/longjmp. Also, it
may impact the processing time especially when the number of samples
with stitched LBRs are huge.
Add an option to enable the approach.
Committer testing:
Using the same perf.data as with the latest cset committer testing
section:
$ perf script --stitch-lbr
<SNIP>
tchain_edit 11131 15164.984292: 437491 cycles:u:
401106 f43+0x0 (/wb/tchain_edit)
40114c f42+0x18 (/wb/tchain_edit)
401172 f41+0xe (/wb/tchain_edit)
401194 f40+0x0 (/wb/tchain_edit)
40119b f39+0x0 (/wb/tchain_edit)
4011a2 f38+0x0 (/wb/tchain_edit)
4011a9 f37+0x0 (/wb/tchain_edit)
4011b0 f36+0x0 (/wb/tchain_edit)
4011b7 f35+0x0 (/wb/tchain_edit)
4011be f34+0x0 (/wb/tchain_edit)
4011c5 f33+0x0 (/wb/tchain_edit)
4011cc f32+0x0 (/wb/tchain_edit)
401207 f31+0x34 (/wb/tchain_edit)
401212 f30+0x0 (/wb/tchain_edit)
401219 f29+0x0 (/wb/tchain_edit)
401220 f28+0x0 (/wb/tchain_edit)
401227 f27+0x0 (/wb/tchain_edit)
40122e f26+0x0 (/wb/tchain_edit)
401235 f25+0x0 (/wb/tchain_edit)
40123c f24+0x0 (/wb/tchain_edit)
401243 f23+0x0 (/wb/tchain_edit)
40124a f22+0x0 (/wb/tchain_edit)
401251 f21+0x0 (/wb/tchain_edit)
401258 f20+0x0 (/wb/tchain_edit)
40125f f19+0x0 (/wb/tchain_edit)
401266 f18+0x0 (/wb/tchain_edit)
40126d f17+0x0 (/wb/tchain_edit)
401274 f16+0x0 (/wb/tchain_edit)
40127b f15+0x0 (/wb/tchain_edit)
401282 f14+0x0 (/wb/tchain_edit)
401289 f13+0x0 (/wb/tchain_edit)
401290 f12+0x0 (/wb/tchain_edit)
401297 f11+0x0 (/wb/tchain_edit)
40129e f10+0x0 (/wb/tchain_edit)
4012a5 f9+0x0 (/wb/tchain_edit)
4012ac f8+0x0 (/wb/tchain_edit)
4012b3 f7+0x0 (/wb/tchain_edit)
4012ba f6+0x0 (/wb/tchain_edit)
4012c1 f5+0x0 (/wb/tchain_edit)
4012c8 f4+0x0 (/wb/tchain_edit)
4012cf f3+0x0 (/wb/tchain_edit)
4012d6 f2+0x0 (/wb/tchain_edit)
4012dd f1+0x0 (/wb/tchain_edit)
4012e4 main+0x0 (/wb/tchain_edit)
7f41a5016f41 __libc_start_main+0xf1 (/usr/lib64/libc-2.29.so)
<SNIP>
$
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-15-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
With the LBR stitching approach, the reconstructed LBR call stack can
break the HW limitation. However, it may reconstruct invalid call stacks
in some cases, e.g. exception handing such as setjmp/longjmp. Also, it
may impact the processing time especially when the number of samples
with stitched LBRs are huge.
Add an option to enable the approach.
# To display the perf.data header info, please use
# --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 6K of event 'cycles'
# Event count (approx.): 6492797701
#
# Children Self Command Shared Object Symbol
# ........ ........ ............... ..................
# .................................
#
99.99% 99.99% tchain_edit tchain_edit [.] f43
|
---main
f1
f2
f3
f4
f5
f6
f7
f8
f9
f10
f11
f12
f13
f14
f15
f16
f17
f18
f19
f20
f21
f22
f23
f24
f25
f26
f27
f28
f29
f30
f31
|
--99.65%--f32
f33
f34
f35
f36
f37
f38
f39
f40
f41
f42
f43
Committer testing:
$ perf record --call-graph lbr /wb/tchain_edit
[ perf record: Woken up 23 times to write data ]
[ perf record: Captured and wrote 5.578 MB perf.data (6839 samples) ]
$ perf report --header-only | egrep 'cpu(desc|.*capabilities)'
# cpudesc : Intel(R) Core(TM) i5-7500 CPU @ 3.40GHz
# cpu pmu capabilities: branches=32, max_precise=3, pmu_name=skylake
$
Before:
$ perf report --no-children --stdio
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 6K of event 'cycles:u'
# Event count (approx.): 6459523879
#
# Overhead Command Shared Object Symbol
# ........ ........... ................ .......................
#
99.95% tchain_edit tchain_edit [.] f43
|
--99.92%--f43
f42
f41
f40
f39
f38
f37
f36
f35
f34
f33
f32
f31
f30
f29
f28
f27
f26
f25
f24
f23
f22
f21
f20
f19
f18
f17
f16
f15
f14
f13
f12
f11
0.03% tchain_edit tchain_edit [.] f42
0.01% tchain_edit tchain_edit [.] f41
0.00% tchain_edit tchain_edit [.] f31
0.00% tchain_edit ld-2.29.so [.] _dl_relocate_object
0.00% tchain_edit ld-2.29.so [.] memmove
0.00% tchain_edit [unknown] [k] 0xffffffff93a00b17
After:
$ perf report --stitch-lbr --no-children --stdio
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 6K of event 'cycles:u'
# Event count (approx.): 6459496645
#
# Overhead Command Shared Object Symbol
# ........ ........... ................ ........................
#
99.97% tchain_edit tchain_edit [.] f43
|
--99.93%--f43
f42
f41
f40
f39
f38
f37
f36
f35
f34
f33
f32
f31
f30
f29
f28
f27
f26
f25
f24
f23
f22
f21
f20
f19
f18
f17
f16
f15
f14
f13
f12
f11
f10
f9
f8
f7
f6
f5
f4
f3
f2
f1
main
__libc_start_main
0.02% tchain_edit [unknown] [k] 0xffffffff93a00b17
0.01% tchain_edit tchain_edit [.] f31
0.00% tchain_edit ld-2.29.so [.] _dl_important_hwcaps
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-14-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
In LBR call stack mode, the depth of reconstructed LBR call stack limits
to the number of LBR registers.
For example, on skylake, the depth of reconstructed LBR call stack is
always <= 32.
# To display the perf.data header info, please use
# --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 6K of event 'cycles'
# Event count (approx.): 6487119731
#
# Children Self Command Shared Object Symbol
# ........ ........ ............... ..................
# ................................
99.97% 99.97% tchain_edit tchain_edit [.] f43
|
--99.64%--f11
f12
f13
f14
f15
f16
f17
f18
f19
f20
f21
f22
f23
f24
f25
f26
f27
f28
f29
f30
f31
f32
f33
f34
f35
f36
f37
f38
f39
f40
f41
f42
f43
For a call stack which is deeper than LBR limit, HW will overwrite the
LBR register with oldest branch. Only partial call stacks can be
reconstructed.
However, the overwritten LBRs may still be retrieved from previous
sample. At that moment, HW hasn't overwritten the LBR registers yet.
Perf tools can stitch those overwritten LBRs on current call stacks to
get a more complete call stack.
To determine if LBRs can be stitched, perf tools need to compare current
sample with previous sample.
- They should have identical LBR records (Same from, to and flags
values, and the same physical index of LBR registers).
- The searching starts from the base-of-stack of current sample.
Once perf determines to stitch the previous LBRs, the corresponding LBR
cursor nodes will be copied to 'lists'. The 'lists' is to track the LBR
cursor nodes which are going to be stitched.
When the stitching is over, the nodes will not be freed immediately.
They will be moved to 'free_lists'. Next stitching may reuse the space.
Both 'lists' and 'free_lists' will be freed when all samples are
processed.
Committer notes:
Fix the intel-pt.c initialization of the union with 'struct
branch_flags', that breaks the build with its unnamed union on older gcc
versions.
Uninline thread__free_stitch_list(), as it grew big and started dragging
includes to thread.h, so move it to thread.c where what it needs in
terms of headers are already there.
This fixes the build in several systems such as debian:experimental when
cross building to the MIPS32 architecture, i.e. in the other cases what
was needed was being included by sheer luck.
In file included from builtin-sched.c:11:
util/thread.h: In function 'thread__free_stitch_list':
util/thread.h:169:3: error: implicit declaration of function 'free' [-Werror=implicit-function-declaration]
169 | free(pos);
| ^~~~
util/thread.h:169:3: error: incompatible implicit declaration of built-in function 'free' [-Werror]
util/thread.h:19:1: note: include '<stdlib.h>' or provide a declaration of 'free'
18 | #include "callchain.h"
+++ |+#include <stdlib.h>
19 |
util/thread.h:174:3: error: incompatible implicit declaration of built-in function 'free' [-Werror]
174 | free(pos);
| ^~~~
util/thread.h:174:3: note: include '<stdlib.h>' or provide a declaration of 'free'
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-13-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
The cursor nodes which generates from sample are eventually added into
callchain. To avoid generating cursor nodes from previous samples again,
the previous cursor nodes are also saved for LBR stitching approach.
Some option, e.g. hide-unresolved, may hide some LBRs. Add a variable
'valid' in struct callchain_cursor_node to indicate this case. The LBR
stitching approach will only append the valid cursor nodes from previous
samples later.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-12-kan.liang@linux.intel.com
[ Use zfree() instead of open coded equivalent, and use it when freeing members of structs ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
To retrieve the overwritten LBRs from previous sample for LBR stitching
approach, perf has to save the previous sample.
Only allocate the struct lbr_stitch once, when LBR stitching approach is
enabled and kernel supports hw_idx.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-11-kan.liang@linux.intel.com
[ Use zalloc()/zfree() for thread->lbr_stitch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
The LBR stitch approach should be disabled by default. Because
- The stitching approach base on LBR call stack technology. The known
limitations of LBR call stack technology still apply to the approach,
e.g. Exception handing such as setjmp/longjmp will have calls/returns
not match.
- This approach is not foolproof. There can be cases where it creates
incorrect call stacks from incorrect matches. There is no attempt to
validate any matches in another way.
The 'lbr_stitch_enable' is used to indicate whether enable LBR stitch
approach, which is disabled by default. The following patch will
introduce a new option for each tools to enable the LBR stitch
approach.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-10-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
Both caller and callee needs to add ip from LBR to callchain.
Factor out lbr_callchain_add_lbr_ip() to improve code readability.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-9-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
Both caller and callee needs to add kernel ip to callchain. Factor out
lbr_callchain_add_kernel_ip() to improve code readability.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-8-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
LBR only collect the user call stack. To reconstruct a call stack, both
kernel call stack and user call stack are required. The function
resolve_lbr_callchain_sample() mix the kernel call stack and user call
stack.
Now, with the help of HW idx, perf tool can reconstruct a more complete
call stack by adding some user call stack from previous sample. However,
current implementation is hard to be extended to support it.
Current code path for resolve_lbr_callchain_sample()
for (j = 0; j < mix_chain_nr; j++) {
if (ORDER_CALLEE) {
if (kernel callchain)
Fill callchain info
else if (LBR callchain)
Fill callchain info
} else {
if (LBR callchain)
Fill callchain info
else if (kernel callchain)
Fill callchain info
}
add_callchain_ip();
}
With the patch,
if (ORDER_CALLEE) {
for (j = 0; j < NUM of kernel callchain) {
Fill callchain info
add_callchain_ip();
}
for (; j < mix_chain_nr) {
Fill callchain info
add_callchain_ip();
}
} else {
for (; j < NUM of LBR callchain) {
Fill callchain info
add_callchain_ip();
}
for (j = 0; j < mix_chain_nr) {
Fill callchain info
add_callchain_ip();
}
}
No functional changes.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-7-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
The indent is unnecessary in resolve_lbr_callchain_sample. Removing it
will make the following patch simpler.
Current code path for resolve_lbr_callchain_sample()
/* LBR only affects the user callchain */
if (i != chain_nr) {
body of the function
....
return 1;
}
return 0;
With the patch,
/* LBR only affects the user callchain */
if (i == chain_nr)
return 0;
body of the function
...
return 1;
No functional changes.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-6-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
To stitch LBR call stack, the max LBR information is required. So the
CPU PMU capabilities information has to be stored in perf header.
Add a new feature HEADER_CPU_PMU_CAPS for CPU PMU capabilities.
Retrieve all CPU PMU capabilities, not just max LBR information.
Add variable max_branches to facilitate future usage.
Committer testing:
# ls -la /sys/devices/cpu/caps/
total 0
drwxr-xr-x. 2 root root 0 Apr 17 10:53 .
drwxr-xr-x. 6 root root 0 Apr 17 07:02 ..
-r--r--r--. 1 root root 4096 Apr 17 10:53 max_precise
#
# cat /sys/devices/cpu/caps/max_precise
0
# perf record sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.033 MB perf.data (7 samples) ]
#
# perf report --header-only | egrep 'cpu(desc|.*capabilities)'
# cpudesc : AMD Ryzen 5 3600X 6-Core Processor
# cpu pmu capabilities: max_precise=0
#
And then on an Intel machine:
$ ls -la /sys/devices/cpu/caps/
total 0
drwxr-xr-x. 2 root root 0 Apr 17 10:51 .
drwxr-xr-x. 6 root root 0 Apr 17 10:04 ..
-r--r--r--. 1 root root 4096 Apr 17 11:37 branches
-r--r--r--. 1 root root 4096 Apr 17 10:51 max_precise
-r--r--r--. 1 root root 4096 Apr 17 11:37 pmu_name
$ cat /sys/devices/cpu/caps/max_precise
3
$ cat /sys/devices/cpu/caps/branches
32
$ cat /sys/devices/cpu/caps/pmu_name
skylake
$ perf record sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.001 MB perf.data (8 samples) ]
$ perf report --header-only | egrep 'cpu(desc|.*capabilities)'
# cpudesc : Intel(R) Core(TM) i5-7500 CPU @ 3.40GHz
# cpu pmu capabilities: branches=32, max_precise=3, pmu_name=skylake
$
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-3-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
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The current rXXXX event specification creates event under PERF_TYPE_RAW
pmu type. This change allows to use rXXXX within pmu syntax, so it's
type is used via the following syntax:
-e 'cpu/r3c/'
-e 'cpum_cf/r0/'
The XXXX number goes directly to perf_event_attr::config the same way as
in '-e rXXXX' event. The perf_event_attr::type is filled with pmu type.
Committer testing:
So, lets see what goes in perf_event_attr::config for, say, the
'instructions' PERF_TYPE_HARDWARE (0) event, first we should look at how
to encode this event as a PERF_TYPE_RAW event for this specific CPU, an
AMD Ryzen 5:
# cat /sys/devices/cpu/events/instructions
event=0xc0
#
Then try with it _and_ the instruction, just to see that they are close
enough:
# perf stat -e rc0,instructions sleep 1
Performance counter stats for 'sleep 1':
919,794 rc0
919,898 instructions
1.000754579 seconds time elapsed
0.000715000 seconds user
0.000000000 seconds sys
#
Now we should try, before this patch, the PMU event encoding:
# perf stat -e cpu/rc0/ sleep 1
event syntax error: 'cpu/rc0/'
\___ unknown term
valid terms: event,edge,inv,umask,cmask,config,config1,config2,name,period,percore
#
Now with this patch, the three ways of specifying the 'instructions' CPU
counter are accepted:
# perf stat -e cpu/rc0/,rc0,instructions sleep 1
Performance counter stats for 'sleep 1':
892,948 cpu/rc0/
893,052 rc0
893,156 instructions
1.000931819 seconds time elapsed
0.000916000 seconds user
0.000000000 seconds sys
#
Requested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20200416221405.437788-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
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This will allow parent makefiles to pass values to asciidoc.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Jiwei Sun <jiwei.sun@windriver.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: yuzhoujian <yuzhoujian@didichuxing.com>
Link: http://lore.kernel.org/lkml/20200416162058.201954-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
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The PMU capabilities information, which is located at
/sys/bus/event_source/devices/<dev>/caps, is required by perf tool. For
example, the max LBR information is required to stitch LBR call stack.
Add perf_pmu__caps_parse() to parse the PMU capabilities information.
The information is stored in a list.
The following patch will store the capabilities information in perf
header.
Committer notes:
Here's an example of such directories and its files in an i5 7th gen
machine:
[root@seventh ~]# ls -lad /sys/bus/event_source/devices/*/caps
drwxr-xr-x. 2 root root 0 Apr 14 13:33 /sys/bus/event_source/devices/cpu/caps
drwxr-xr-x. 2 root root 0 Apr 14 13:33 /sys/bus/event_source/devices/intel_pt/caps
[root@seventh ~]# ls -la /sys/bus/event_source/devices/intel_pt/caps
total 0
drwxr-xr-x. 2 root root 0 Apr 14 13:33 .
drwxr-xr-x. 5 root root 0 Apr 14 13:12 ..
-r--r--r--. 1 root root 4096 Apr 16 13:10 cr3_filtering
-r--r--r--. 1 root root 4096 Apr 16 11:42 cycle_thresholds
-r--r--r--. 1 root root 4096 Apr 16 13:10 ip_filtering
-r--r--r--. 1 root root 4096 Apr 16 13:10 max_subleaf
-r--r--r--. 1 root root 4096 Apr 14 13:33 mtc
-r--r--r--. 1 root root 4096 Apr 14 13:33 mtc_periods
-r--r--r--. 1 root root 4096 Apr 16 13:10 num_address_ranges
-r--r--r--. 1 root root 4096 Apr 16 13:10 output_subsys
-r--r--r--. 1 root root 4096 Apr 16 13:10 payloads_lip
-r--r--r--. 1 root root 4096 Apr 16 13:10 power_event_trace
-r--r--r--. 1 root root 4096 Apr 14 13:33 psb_cyc
-r--r--r--. 1 root root 4096 Apr 14 13:33 psb_periods
-r--r--r--. 1 root root 4096 Apr 16 13:10 ptwrite
-r--r--r--. 1 root root 4096 Apr 16 13:10 single_range_output
-r--r--r--. 1 root root 4096 Apr 16 12:03 topa_multiple_entries
-r--r--r--. 1 root root 4096 Apr 16 13:10 topa_output
[root@seventh ~]# cat /sys/bus/event_source/devices/intel_pt/caps/topa_output
1
[root@seventh ~]# cat /sys/bus/event_source/devices/intel_pt/caps/topa_multiple_entries
1
[root@seventh ~]# cat /sys/bus/event_source/devices/intel_pt/caps/mtc
1
[root@seventh ~]# cat /sys/bus/event_source/devices/intel_pt/caps/power_event_trace
0
[root@seventh ~]#
[root@seventh ~]# ls -la /sys/bus/event_source/devices/cpu/caps/
total 0
drwxr-xr-x. 2 root root 0 Apr 14 13:33 .
drwxr-xr-x. 6 root root 0 Apr 14 13:12 ..
-r--r--r--. 1 root root 4096 Apr 16 13:10 branches
-r--r--r--. 1 root root 4096 Apr 14 13:33 max_precise
-r--r--r--. 1 root root 4096 Apr 16 13:10 pmu_name
[root@seventh ~]# cat /sys/bus/event_source/devices/cpu/caps/max_precise
3
[root@seventh ~]# cat /sys/bus/event_source/devices/cpu/caps/branches
32
[root@seventh ~]# cat /sys/bus/event_source/devices/cpu/caps/pmu_name
skylake
[root@seventh ~]#
Wow, first time I've heard about
/sys/bus/event_source/devices/cpu/caps/max_precise, I think I'll use it!
:-)
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pavel Gerasimov <pavel.gerasimov@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Link: http://lore.kernel.org/lkml/20200319202517.23423-2-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
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According to the API, if memory allocation wasn't possible, or some
other error occurs, asprintf will return -1, and the contents of strp
below are undefined.
int asprintf(char **strp, const char *fmt, ...);
This patch takes care of return value of asprintf to make it less error
prone and prevent the following build warning.
ignoring return value of ‘asprintf’, declared with attribute warn_unused_result [-Wunused-result]
Signed-off-by: He Zhe <zhe.he@windriver.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: hewenliang4@huawei.com
Link: http://lore.kernel.org/lkml/1582163930-233692-1-git-send-email-zhe.he@windriver.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
When it is not possible for a non-privilege perf command to monitor at
the kernel level (:k), the fallback code forces a :u. That works if the
event was previously monitoring both levels. But if the event was
already constrained to kernel only, then it does not make sense to
restrict it to user only.
Given the code works by exclusion, a kernel only event would have:
attr->exclude_user = 1
The fallback code would add:
attr->exclude_kernel = 1
In the end the end would not monitor in either the user level or kernel
level. In other words, it would count nothing.
An event programmed to monitor kernel only cannot be switched to user
only without seriously warning the user.
This patch forces an error in this case to make it clear the request
cannot really be satisfied.
Behavior with paranoid 1:
$ sudo bash -c "echo 1 > /proc/sys/kernel/perf_event_paranoid"
$ perf stat -e cycles:k sleep 1
Performance counter stats for 'sleep 1':
1,520,413 cycles:k
1.002361664 seconds time elapsed
0.002480000 seconds user
0.000000000 seconds sys
Old behavior with paranoid 2:
$ sudo bash -c "echo 2 > /proc/sys/kernel/perf_event_paranoid"
$ perf stat -e cycles:k sleep 1
Performance counter stats for 'sleep 1':
0 cycles:ku
1.002358127 seconds time elapsed
0.002384000 seconds user
0.000000000 seconds sys
New behavior with paranoid 2:
$ sudo bash -c "echo 2 > /proc/sys/kernel/perf_event_paranoid"
$ perf stat -e cycles:k sleep 1
Error:
You may not have permission to collect stats.
Consider tweaking /proc/sys/kernel/perf_event_paranoid,
which controls use of the performance events system by
unprivileged users (without CAP_PERFMON or CAP_SYS_ADMIN).
The current value is 2:
-1: Allow use of (almost) all events by all users
Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK
>= 0: Disallow ftrace function tracepoint by users without CAP_PERFMON or CAP_SYS_ADMIN
Disallow raw tracepoint access by users without CAP_SYS_PERFMON or CAP_SYS_ADMIN
>= 1: Disallow CPU event access by users without CAP_PERFMON or CAP_SYS_ADMIN
>= 2: Disallow kernel profiling by users without CAP_PERFMON or CAP_SYS_ADMIN
To make this setting permanent, edit /etc/sysctl.conf too, e.g.:
kernel.perf_event_paranoid = -1
v2 of this patch addresses the review feedback from jolsa@redhat.com.
Signed-off-by: Stephane Eranian <eranian@google.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20200414161550.225588-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
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When AUX area events are used in sampling mode, they must be the group
leader, but the group leader is also used for leader-sampling. However,
it is not desirable to use an AUX area event as the leader for
leader-sampling, because it doesn't have any samples of its own. To support
leader-sampling with AUX area events, use the 2nd event of the group as the
"leader" for the purposes of leader-sampling.
Example:
# perf record --kcore --aux-sample -e '{intel_pt//,cycles,instructions}:S' -c 10000 uname
[ perf record: Woken up 3 times to write data ]
[ perf record: Captured and wrote 0.786 MB perf.data ]
# perf report
Samples: 380 of events 'anon group { cycles, instructions }', Event count (approx.): 3026164
Children Self Command Shared Object Symbol
+ 38.76% 42.65% 0.00% 0.00% uname [kernel.kallsyms] [k] __x86_indirect_thunk_rax
+ 35.82% 31.33% 0.00% 0.00% uname ld-2.28.so [.] _dl_start_user
+ 34.29% 29.74% 0.55% 0.47% uname ld-2.28.so [.] _dl_start
+ 33.73% 28.62% 1.60% 0.97% uname ld-2.28.so [.] dl_main
+ 33.19% 29.04% 0.52% 0.32% uname ld-2.28.so [.] _dl_sysdep_start
+ 27.83% 33.74% 0.00% 0.00% uname [kernel.kallsyms] [k] do_syscall_64
+ 26.76% 33.29% 0.00% 0.00% uname [kernel.kallsyms] [k] entry_SYSCALL_64_after_hwframe
+ 23.78% 20.33% 5.97% 5.25% uname [kernel.kallsyms] [k] page_fault
+ 23.18% 24.60% 0.00% 0.00% uname libc-2.28.so [.] __libc_start_main
+ 22.64% 24.37% 0.00% 0.00% uname uname [.] _start
+ 21.04% 23.27% 0.00% 0.00% uname uname [.] main
+ 19.48% 18.08% 3.72% 3.64% uname ld-2.28.so [.] _dl_relocate_object
+ 19.47% 21.81% 0.00% 0.00% uname libc-2.28.so [.] setlocale
+ 19.44% 21.56% 0.52% 0.61% uname libc-2.28.so [.] _nl_find_locale
+ 17.87% 19.66% 0.00% 0.00% uname libc-2.28.so [.] _nl_load_locale_from_archive
+ 15.71% 13.73% 0.53% 0.52% uname [kernel.kallsyms] [k] do_page_fault
+ 15.18% 13.21% 1.03% 0.68% uname [kernel.kallsyms] [k] handle_mm_fault
+ 14.15% 12.53% 1.01% 1.12% uname [kernel.kallsyms] [k] __handle_mm_fault
+ 12.03% 9.67% 0.54% 0.32% uname ld-2.28.so [.] _dl_map_object
+ 10.55% 8.48% 0.00% 0.00% uname ld-2.28.so [.] openaux
+ 10.55% 20.20% 0.52% 0.61% uname libc-2.28.so [.] __run_exit_handlers
Comnmitter notes:
Fixed up this problem:
util/record.c: In function ‘perf_evlist__config’:
util/record.c:256:3: error: too few arguments to function ‘perf_evsel__config_leader_sampling’
256 | perf_evsel__config_leader_sampling(evsel);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
util/record.c:190:13: note: declared here
190 | static void perf_evsel__config_leader_sampling(struct evsel *evsel,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200401101613.6201-17-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
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Tools find the correct evsel, and therefore read format, using the event
ID, so it isn't necessary for all read formats to be the same. In the
case of leader-sampling of AUX area events, dummy tracking events will
have a different read format, so relax the validation to become a debug
message only.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200401101613.6201-16-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
In preparation for adding support for leader sampling with AUX area events.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200401101613.6201-15-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
Move leader-sampling configuration in preparation for adding support for
leader sampling with AUX area events.
Committer notes:
It only makes sense when configuring an evsel that is part of an evlist,
so the only case where it is called outside perf_evlist__config(), in
some 'perf test' entry, is safe, and even there we should just use
perf_evlist__config(), but since in that case we have just one evsel in
the evlist, it is equivalent.
Also fixed up this problem:
util/record.c: In function ‘perf_evlist__config’:
util/record.c:223:3: error: too many arguments to function ‘perf_evsel__config_leader_sampling’
223 | perf_evsel__config_leader_sampling(evsel, evlist);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
util/record.c:170:13: note: declared here
170 | static void perf_evsel__config_leader_sampling(struct evsel *evsel)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200401101613.6201-14-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
perf_evsel__is_aux_event()
Move and globalize 2 functions from the auxtrace specific sources so
that they can be reused.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200401101613.6201-13-adrian.hunter@intel.com
[ Move to pmu.c, as moving to evsel.h breaks the python binding ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
We are using abort() so let's include stdlib.h
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
|
|
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
|
