linux.git/tools/perf, branch v5.18

perf session: Fix Intel LBR callstack entries and nr print message

2022-05-21T17:56:24+00:00

When generating callstack information from branch_stack(Intel LBR), the
actual number of callstack entry should be bigger than the number of
branch_stack, for example:

	branch_stack records:
		B() -> C()
		A() -> B()
	converted callstack records should be:
		C()
		B()
		A()
though, the number of callstack equals
to the number of branch stack plus 1.

This patch fixes above issue in branch_stack__printf(). For example,

	# echo 'scale=2000; 4*a(1)' > cmd
	# perf record --call-graph lbr bc -l < cmd

Before applying this patch, `perf script -D` output:

	1220022677386876 0x2a40 [0xd8]: PERF_RECORD_SAMPLE(IP, 0x4002): 17990/17990: 0x40a6d6 period: 894172 addr: 0
	... LBR call chain: nr:8
	.....  0: fffffffffffffe00
	.....  1: 000000000040a410
	.....  2: 000000000040573c
	.....  3: 0000000000408650
	.....  4: 00000000004022f2
	.....  5: 00000000004015f5
	.....  6: 00007f5ed6dcb553
	.....  7: 0000000000401698
	... FP chain: nr:2
	.....  0: fffffffffffffe00
	.....  1: 000000000040a6d8
	... branch callstack: nr:6    # which is not consistent with LBR records.
	.....  0: 000000000040a410
	.....  1: 0000000000408650    # ditto
	.....  2: 00000000004022f2
	.....  3: 00000000004015f5
	.....  4: 00007f5ed6dcb553
	.....  5: 0000000000401698
	 ... thread: bc:17990
	 ...... dso: /usr/bin/bc
	bc 17990 1220022.677386:     894172 cycles:
			  40a410 [unknown] (/usr/bin/bc)
			  40573c [unknown] (/usr/bin/bc)
			  408650 [unknown] (/usr/bin/bc)
			  4022f2 [unknown] (/usr/bin/bc)
			  4015f5 [unknown] (/usr/bin/bc)
		    7f5ed6dcb553 __libc_start_main+0xf3 (/usr/lib64/libc-2.17.so)
			  401698 [unknown] (/usr/bin/bc)

After applied:

	1220022677386876 0x2a40 [0xd8]: PERF_RECORD_SAMPLE(IP, 0x4002): 17990/17990: 0x40a6d6 period: 894172 addr: 0
	... LBR call chain: nr:8
	.....  0: fffffffffffffe00
	.....  1: 000000000040a410
	.....  2: 000000000040573c
	.....  3: 0000000000408650
	.....  4: 00000000004022f2
	.....  5: 00000000004015f5
	.....  6: 00007f5ed6dcb553
	.....  7: 0000000000401698
	... FP chain: nr:2
	.....  0: fffffffffffffe00
	.....  1: 000000000040a6d8
	... branch callstack: nr:7
	.....  0: 000000000040a410
	.....  1: 000000000040573c
	.....  2: 0000000000408650
	.....  3: 00000000004022f2
	.....  4: 00000000004015f5
	.....  5: 00007f5ed6dcb553
	.....  6: 0000000000401698
	 ... thread: bc:17990
	 ...... dso: /usr/bin/bc
	bc 17990 1220022.677386:     894172 cycles:
			  40a410 [unknown] (/usr/bin/bc)
			  40573c [unknown] (/usr/bin/bc)
			  408650 [unknown] (/usr/bin/bc)
			  4022f2 [unknown] (/usr/bin/bc)
			  4015f5 [unknown] (/usr/bin/bc)
		    7f5ed6dcb553 __libc_start_main+0xf3 (/usr/lib64/libc-2.17.so)
			  401698 [unknown] (/usr/bin/bc)

Change from v1:
	- refined code style according to Jiri's review comments.

Signed-off-by: Chengdong Li 
Acked-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexey Bayduraev 
Cc: Andi Kleen 
Cc: German Gomez 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Peter Zijlstra 
Cc: Riccardo Mancini 
Cc: likexu@tencent.com
Link: https://lore.kernel.org/r/20220517015726.96131-1-chengdongli@tencent.com
Signed-off-by: Arnaldo Carvalho de Melo

perf test bpf: Skip test if clang is not present

2022-05-21T17:54:21+00:00

Perf BPF filter test fails in environment where "clang" is not
installed.

Test failure logs:

<<>>
 42: BPF filter                    :
 42.1: Basic BPF filtering         : Skip
 42.2: BPF pinning                 : FAILED!
 42.3: BPF prologue generation     : FAILED!
<<>>

Enabling verbose option provided debug logs which says clang/llvm needs
to be installed. Snippet of verbose logs:

<<>>
 42.2: BPF pinning                  :
 --- start ---
test child forked, pid 61423
ERROR:	unable to find clang.
Hint:	Try to install latest clang/llvm to support BPF.
        Check your $PATH

<>

Failed to compile test case: 'Basic BPF llvm compile'
Unable to get BPF object, fix kbuild first
test child finished with -1
 ---- end ----
BPF filter subtest 2: FAILED!
<<>>

Here subtests, "BPF pinning" and "BPF prologue generation" failed and
logs shows clang/llvm is needed. After installing clang, testcase
passes.

Reason on why subtest failure happens though logs has proper debug
information:

Main function __test__bpf calls test_llvm__fetch_bpf_obj by
passing 4th argument as true ( 4th arguments maps to parameter
"force" in test_llvm__fetch_bpf_obj ). But this will cause
test_llvm__fetch_bpf_obj to skip the check for clang/llvm.

Snippet of code part which checks for clang based on
parameter "force" in test_llvm__fetch_bpf_obj:

<<>>
if (!force && (!llvm_param.user_set_param &&
<<>>

Since force is set to "false", test won't get skipped and fails to
compile test case. The BPF code compilation needs clang, So pass the
fourth argument as "false" and also skip the test if reason for return
is "TEST_SKIP"

After the patch:

<<>>
 42: BPF filter                    :
 42.1: Basic BPF filtering         : Skip
 42.2: BPF pinning                 : Skip
 42.3: BPF prologue generation     : Skip
<<>>

Fixes: ba1fae431e74bb42 ("perf test: Add 'perf test BPF'")
Reviewed-by: Kajol Jain 
Signed-off-by: Athira Jajeev 
Acked-by: Ian Rogers 
Cc: Disha Goel 
Cc: Jiri Olsa 
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Madhavan Srinivasan 
Cc: Michael Ellerman 
Cc: Nageswara R Sastry 
Cc: Wang Nan 
Link: https://lore.kernel.org/r/20220511115438.84032-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf test session topology: Fix test to skip the test in guest environment

2022-05-21T17:52:33+00:00

The session topology test fails in powerpc pSeries platform.

Test logs:

  <<>>
  Session topology : FAILED!
  <<>>

This testcases tests cpu topology by checking the core_id and socket_id
stored in perf_env from perf session. The data from perf session is
compared with the cpu topology information from
"/sys/devices/system/cpu/cpuX/topology" like core_id,
physical_package_id.

In case of virtual environment, detail like physical_package_id is
restricted to be exposed. Hence physical_package_id is set to -1. The
testcase fails on such platforms since socket_id can't be fetched from
topology info.

Skip the testcase in powerpc if physical_package_id returns -1.

Reviewed-by: Kajol Jain 
Signed-off-by: Athira Rajeev ---
Tested-by: Disha Goel 
Acked-by: Ian Rogers 
Cc: Jiri Olsa 
Cc: Madhavan Srinivasan 
Cc: Michael Ellerman 
Cc: Nageswara R Sastry 
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20220511114959.84002-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf bench numa: Address compiler error on s390

2022-05-21T17:45:19+00:00

The compilation on s390 results in this error:

  # make DEBUG=y bench/numa.o
  ...
  bench/numa.c: In function ‘__bench_numa’:
  bench/numa.c:1749:81: error: ‘%d’ directive output may be truncated
              writing between 1 and 11 bytes into a region of size between
              10 and 20 [-Werror=format-truncation=]
  1749 |        snprintf(tname, sizeof(tname), "process%d:thread%d", p, t);
                                                               ^~
  ...
  bench/numa.c:1749:64: note: directive argument in the range
                 [-2147483647, 2147483646]
  ...
  #

The maximum length of the %d replacement is 11 characters because of the
negative sign.  Therefore extend the array by two more characters.

Output after:

  # make  DEBUG=y bench/numa.o > /dev/null 2>&1; ll bench/numa.o
  -rw-r--r-- 1 root root 418320 May 19 09:11 bench/numa.o
  #

Fixes: 3aff8ba0a4c9c919 ("perf bench numa: Avoid possible truncation when using snprintf()")
Suggested-by: Namhyung Kim 
Signed-off-by: Thomas Richter 
Cc: Heiko Carstens 
Cc: Sumanth Korikkar 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Link: https://lore.kernel.org/r/20220520081158.2990006-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Avoid shell test description infinite loop

2022-05-21T17:45:19+00:00

for_each_shell_test() is already strict in expecting tests to be files
and executable. It is sometimes possible when it iterates over all files
that it finds one that is executable and lacks a newline character. When
this happens the loop never terminates as it doesn't check for EOF.

Add the EOF check to make this loop at least bounded by the file size.

If the description is returned as NULL then also skip the test.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Marco Elver 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Riccardo Mancini 
Cc: Sohaib Mohamed 
Cc: Stephane Eranian 
Link: https://lore.kernel.org/r/20220517204144.645913-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf regs x86: Fix arch__intr_reg_mask() for the hybrid platform

2022-05-21T17:45:19+00:00

The X86 specific arch__intr_reg_mask() is to check whether the kernel
and hardware can collect XMM registers. But it doesn't work on some
hybrid platform.

Without the patch on ADL-N:

  $ perf record -I?
  available registers: AX BX CX DX SI DI BP SP IP FLAGS CS SS R8 R9 R10
  R11 R12 R13 R14 R15

The config of the test event doesn't contain the PMU information. The
kernel may fail to initialize it on the correct hybrid PMU and return
the wrong non-supported information.

Add the PMU information into the config for the hybrid platform. The
same register set is supported among different hybrid PMUs. Checking
the first available one is good enough.

With the patch on ADL-N:

  $ perf record -I?
  available registers: AX BX CX DX SI DI BP SP IP FLAGS CS SS R8 R9 R10
  R11 R12 R13 R14 R15 XMM0 XMM1 XMM2 XMM3 XMM4 XMM5 XMM6 XMM7 XMM8 XMM9
  XMM10 XMM11 XMM12 XMM13 XMM14 XMM15

Fixes: 6466ec14aaf44ff1 ("perf regs x86: Add X86 specific arch__intr_reg_mask()")
Reported-by: Ammy Yi 
Signed-off-by: Kan Liang 
Acked-by: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Xing Zhengjun 
Link: https://lore.kernel.org/r/20220518145125.1494156-1-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Fix "all PMU test" to skip hv_24x7/hv_gpci tests on powerpc

2022-05-21T17:45:06+00:00

"perf all PMU test" picks the input events from "perf list --raw-dump
pmu" list and runs "perf stat -e" for each of the event in the list. In
case of powerpc, the PowerVM environment supports events from hv_24x7
and hv_gpci PMU which is of example format like below:

- hv_24x7/CPM_ADJUNCT_INST,domain=?,core=?/
- hv_gpci/event,partition_id=?/

The value for "?" needs to be filled in depending on system and
respective event. CPM_ADJUNCT_INST needs have core value and domain
value. hv_gpci event needs partition_id.  Similarly, there are other
events for hv_24x7 and hv_gpci having "?" in event format. Hence skip
these events on powerpc platform since values like partition_id, domain
is specific to system and event.

Fixes: 3d5ac9effcc640d5 ("perf test: Workload test of all PMUs")
Signed-off-by: Athira Jajeev 
Acked-by: Ian Rogers 
Cc: Disha Goel 
Cc: Jiri Olsa 
Cc: Kajol Jain 
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Madhavan Srinivasan 
Cc: Michael Ellerman 
Cc: Nageswara R Sastry 
Link: https://lore.kernel.org/r/20220520101236.17249-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Fix and validate CPU map inputs in synthetic PERF_RECORD_STAT events

2022-05-20T13:54:06+00:00

Stat events can come from disk and so need a degree of validation. They
contain a CPU which needs looking up via CPU map to access a counter.

Add the CPU to index translation, alongside validity checking.

Discussion thread:

  https://lore.kernel.org/linux-perf-users/CAP-5=fWQR=sCuiSMktvUtcbOLidEpUJLCybVF6=BRvORcDOq+g@mail.gmail.com/

Fixes: 7ac0089d138f80dc ("perf evsel: Pass cpu not cpu map index to synthesize")
Reported-by: Michael Petlan 
Suggested-by: Michael Petlan 
Signed-off-by: Ian Rogers 
Cc: Alexander Shishkin 
Cc: Alexei Starovoitov 
Cc: Andrii Nakryiko 
Cc: Daniel Borkmann 
Cc: Dave Marchevsky 
Cc: Ian Rogers 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: John Fastabend 
Cc: Kan Liang 
Cc: KP Singh 
Cc: Lv Ruyi 
Cc: Mark Rutland 
Cc: Martin KaFai Lau 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: netdev@vger.kernel.org
Cc: Peter Zijlstra 
Cc: Quentin Monnet 
Cc: Song Liu 
Cc: Stephane Eranian 
Cc: Xing Zhengjun 
Cc: Yonghong Song 
Link: http://lore.kernel.org/lkml/20220519032005.1273691-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf build: Fix check for btf__load_from_kernel_by_id() in libbpf

2022-05-20T12:45:41+00:00

Avi Kivity reported a problem where the __weak
btf__load_from_kernel_by_id() in tools/perf/util/bpf-event.c was being
used and it called btf__get_from_id() in tools/lib/bpf/btf.c that in
turn called back to btf__load_from_kernel_by_id(), resulting in an
endless loop.

Fix this by adding a feature test to check if
btf__load_from_kernel_by_id() is available when building perf with
LIBBPF_DYNAMIC=1, and if not then provide the fallback to the old
btf__get_from_id(), that doesn't call back to btf__load_from_kernel_by_id()
since at that time it didn't exist at all.

Tested on Fedora 35 where we have libbpf-devel 0.4.0 with LIBBPF_DYNAMIC
where we don't have btf__load_from_kernel_by_id() and thus its feature
test fail, not defining HAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID:

  $ cat /tmp/build/perf-urgent/feature/test-libbpf-btf__load_from_kernel_by_id.make.output
  test-libbpf-btf__load_from_kernel_by_id.c: In function ‘main’:
  test-libbpf-btf__load_from_kernel_by_id.c:6:16: error: implicit declaration of function ‘btf__load_from_kernel_by_id’ [-Werror=implicit-function-declaration]
      6 |         return btf__load_from_kernel_by_id(20151128, NULL);
        |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors
  $

  $ nm /tmp/build/perf-urgent/perf | grep btf__load_from_kernel_by_id
  00000000005ba180 T btf__load_from_kernel_by_id
  $

  $ objdump --disassemble=btf__load_from_kernel_by_id -S /tmp/build/perf-urgent/perf

  /tmp/build/perf-urgent/perf:     file format elf64-x86-64
  
  00000000005ba180 :
  #include "record.h"
  #include "util/synthetic-events.h"

  #ifndef HAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID
  struct btf *btf__load_from_kernel_by_id(__u32 id)
  {
    5ba180:	55                   	push   %rbp
    5ba181:	48 89 e5             	mov    %rsp,%rbp
    5ba184:	48 83 ec 10          	sub    $0x10,%rsp
    5ba188:	64 48 8b 04 25 28 00 	mov    %fs:0x28,%rax
    5ba18f:	00 00
    5ba191:	48 89 45 f8          	mov    %rax,-0x8(%rbp)
    5ba195:	31 c0                	xor    %eax,%eax
         struct btf *btf;
  #pragma GCC diagnostic push
  #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
         int err = btf__get_from_id(id, &btf);
    5ba197:	48 8d 75 f0          	lea    -0x10(%rbp),%rsi
    5ba19b:	e8 a0 57 e5 ff       	call   40f940 
    5ba1a0:	89 c2                	mov    %eax,%edx
  #pragma GCC diagnostic pop

         return err ? ERR_PTR(err) : btf;
    5ba1a2:	48 98                	cltq
    5ba1a4:	85 d2                	test   %edx,%edx
    5ba1a6:	48 0f 44 45 f0       	cmove  -0x10(%rbp),%rax
  }
  

Fixes: 218e7b775d368f38 ("perf bpf: Provide a weak btf__load_from_kernel_by_id() for older libbpf versions")
Reported-by: Avi Kivity 
Link: https://lore.kernel.org/linux-perf-users/f0add43b-3de5-20c5-22c4-70aff4af959f@scylladb.com
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lore.kernel.org/linux-perf-users/YobjjFOblY4Xvwo7@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tests: Fix coresight `perf test` failure.

2022-05-09T00:48:49+00:00

Currently the `perf test` always fails the coresight test like:

  89: Check Arm CoreSight trace data recording and synthesized samples: FAILED!

That is because the test_arm_coresight.sh is attempting to SIGINT the
parent but is using $$ rather than $PPID and it sigint's itself when
run under the perf test framework.

Since this is done in a trap clause it ends up returning a non zero
return.

Since $PPID is a bash ism and not all distros are linking /bin/sh to
bash, the alternative parent pid lookups are uglier than just dropping
the kill, and its not strictly needed, lets pick the simple solution and
drop the sigint.

Fixes: 133fe2e617e48ca0 ("perf tests: Improve temp file cleanup in test_arm_coresight.sh")
Reviewed-by: James Clark 
Signed-off-by: Jeremy Linton 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Jeremy Linton 
Link: https://lore.kernel.org/r/20220428151947.290146-1-jeremy.linton@arm.com
Signed-off-by: Arnaldo Carvalho de Melo