On Mon, 29 Jan 2018 22:00:52 +0530 Pintu Kumar <pintu.ping@gmail.com> wrote:
Dear Masami,
Thank you so much for your reply. Please find some of my answers inline.
On Mon, Jan 29, 2018 at 7:47 PM, Masami Hiramatsu <mhiramat@kernel.org> wrote:
On Mon, 29 Jan 2018 13:40:34 +0530 Pintu Kumar <pintu.ping@gmail.com> wrote:
Hi All,
'perf probe' is failing sometimes on 4.9.20 with AMD-64. # perf probe --add schedule schedule is out of .text, skip it. Error: Failed to add events.
If any one have come across this problem please let me know the cause.
Hi Pintu,
Could you run it with --vv?
Ok, I will send verbose output by tomorrow.
Note: I don't have CONFIG_DEBUG_INFO enabled in kernel. Is this the problem?
Without it, you can not probe source-level probe nor trace local variable.
Currently I am facing problem in enabling DEBUG_INFO in our kernel 4.9.20 However, I will try to manually include "-g" option during compilation.
However, I manually copied the vmlinux file to /boot/ directory, but still it does not work.
That doesn't work. CONFIG_DEBUG_INFO option enables gcc to compile kernel with extra debuginfo. Without that option, debuginfo is not generated with vmlinux.
I checked upstream patches until 4.15 but could not find any clue. Please let me know if there is any fixes available for this.
Could you also ensure that you run perf by root user?
Yes I am running with root user.
My concern is sometimes it works but sometimes it fails.
What I thought was that your kernel enables kptr_strict(but maybe not.) Can you also try to find "schedule" and "_etext" functions in /proc/kallsyms?
I still needs to figure out, in which condition it works and which condition it fails.
Yeah, it is important.
Usually I noticed that in fresh reboot case it works.
So, after a while, it doesn't work again? If so, it sounds like a daemon process changes settings in background. Thank you,
Thank you,
Thank You! Regards, Pintu
On Thu, Jan 25, 2018 at 7:09 PM, Pintu Kumar <pintu.ping@gmail.com> wrote:
Hi,
** Changed the subject now, since these issues are related to general perf commands.
Following are the issues:
1) perf probe --add schedule - FAILED output: schedule is out of .text, skip it. Error: Failed to add events.
what is the issue here? Sometimes it pass and sometimes it fails... Similar is the case of 'perf inject' as well.
2) perf test - 1 FAILURE 37.1: Test basic BPF filtering : FAILED! 37.2: Test BPF prologue generation : Skip 37.3: Test BPF relocation checker : Skip
bpf: config program 'func=SyS_epoll_wait' symbol:SyS_epoll_wait file:(null) line:0 offset:0 return:0 lazy:(null) bpf: config 'func=SyS_epoll_wait' is ok Looking at the vmlinux_path (8 entries long) Using /boot/vmlinux for symbols Could not open debuginfo. Try to use symbols. SyS_epoll_wait is out of .text, skip it. bpf_probe: failed to convert perf probe eventsFailed to add events selected by BPF test child finished with -1 ---- end ---- Test BPF filter subtest 0: FAILED!
Looks like both 1,2 are related. Since, CONFIG_DEBUG_INFO is not enabled, I manually copied the vmlinux to /boot/ folder.
------- Some more info:
Kernel build dir is set to /lib/modules/4.9.20-sc-amd-x86-64/build set env: KBUILD_DIR=/lib/modules/4.9.20-sc-amd-x86-64/build unset env: KBUILD_OPTS include option is set to -nostdinc -isystem /usr/lib/gcc/x86_64-linux-gnu/5/include -I./arch/x86/include -I./arch/x86/include/generated/uapi -I./arch/x86/include/generated -I./include -I./arch/x86/include/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h set env: NR_CPUS=8 set env: LINUX_VERSION_CODE=0x40914 set env: CLANG_EXEC=/usr/bin/clang set env: CLANG_OPTIONS=-xc set env: KERNEL_INC_OPTIONS= -nostdinc -isystem /usr/lib/gcc/x86_64-linux-gnu/5/include -I./arch/x86/include -I./arch/x86/include/generated/uapi -I./arch/x86/include/generated -I./include -I./arch/x86/include/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h set env: WORKING_DIR=/lib/modules/4.9.20-sc-amd-x86-64/build
If you have any clue about these failure please help me.
Thanks, Pintu
On Wed, Jan 24, 2018 at 8:23 PM, Pintu Kumar <pintu.ping@gmail.com> wrote:
Hi,
Thanks for your help. Yes it was a sub version issue.
Earlier, while building the kernel I left the SUBLEVEL as blank.
make -j8 bindeb-pkg SUBLEVEL=20
After passing the correct sublevel now the test is working.
But still following are failing:
16: Try 'import perf' in python, checking link problems : FAILED! 37.2: Test BPF prologue generation : FAILED!
This is the error I get:
16: Try 'import perf' in python, checking link problems : --- start --- test child forked, pid 7637 Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named perf test child finished with -1 ---- end ---- Try 'import perf' in python, checking link problems: FAILED!
Looking at the vmlinux_path (8 entries long) symsrc__init: cannot get elf header. Failed to find the path for kernel: Invalid ELF file bpf_probe: failed to convert perf probe eventsFailed to add events selected by BPF test child finished with -1 ---- end ---- Test BPF filter subtest 1: FAILED!
Thanks, Pintu
On Wed, Jan 24, 2018 at 6:39 AM, Wangnan (F) <wangnan0@huawei.com> wrote:
On 2018/1/23 20:37, Pintu Kumar wrote:
Hi All,
I am verifying all perf tests on Ubuntu-16 x86-64 platform using the kernel version 4.9.20. I have installed several others packages including: clang, llvm
But, when I run 'perf test' I get some FAILURE. Specially, 'perf test LLVM' is failing.
Please check the below error logs:
---------------------------------------------------- # perf test LLVM 35: Test LLVM searching and compiling : 35.1: Basic BPF llvm compiling test : FAILED! 35.2: Test kbuild searching : Skip 35.3: Compile source for BPF prologue generation test : Skip 35.4: Compile source for BPF relocation test : Skip ----------------------------------------------------
When I run with -v I get this:
----------------------------------------------------- # perf test -v LLVM 35: Test LLVM searching and compiling : 35.1: Basic BPF llvm compiling test : --- start --- test child forked, pid 3304 Unablt to get kernel version from uname '4.9-xxxx-amd-x86-64' WARNING: unable to get correct kernel building directory. Hint: Set correct kbuild directory using 'kbuild-dir' option in [llvm] section of ~/.perfconfig or set it to "" to suppress kbuild detection.
Unablt to get kernel version from uname '4.9-xxxx-amd-x86-64'
int _version SEC("version") = LINUX_VERSION_CODE; ' | $CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS -DLINUX_VERSION_CODE=$LINUX_VERSION_CODE $CLANG_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf -O2 -o - libbpf: 2129190-4a0 doesn't provide kernel version Failed to parse test case 'Basic BPF llvm compiling test' test child finished with -1 ---- end ---- Test LLVM searching and compiling subtest 0: FAILED! -----------------------------------------------------
Basic BPF LLVM compiling test is failing. It reports that bpf could not able to read the kernel version from uname. Is it because of this that 'perf test LLVM' is failing ?
My uname says: 4.9-xxxx-amd-x86-64
'perf test LLVM' requires a well formed uname string (%d.%d.%d). Please see tools/perf/fetch_kernel_version . If your distro uses another method to report kernel version number (from your uname string, sublevel can't be determined), please help us improve that function like what we have done for ubuntu (checking /proc/version_signature).
My kernel version is: 4.9.20 (from Makefile)
So, I dont think there is any problem with kernel version.
If any body have come across this problem please let me know how to resolve this issue.
Thank You!
Regards, Pintu
-- Masami Hiramatsu <mhiramat@kernel.org>
-- Masami Hiramatsu <mhiramat@kernel.org>