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Linux Kernel contains only C code?
by inventsekar Feb. 2, 2018

Feb. 2, 2018

Hi all, ... 1. May i know, other than C language, is there any other programming language is/are used inside Linux Kernel?!?! is there any c++, Perl, python programs are used for peculiar tasks inside Linux Kernel?!?! 2. I believe some assembly language and shell scripting also used.. how can I check them? Can you point me which part of the source code contains the assembly and shell scripting Best regards Sekar

10 17

Re: clang warning: implicit conversion in intel_ddi.c:1481
by Greg KH Feb. 2, 2018

Feb. 2, 2018

On Fri, Feb 02, 2018 at 12:44:38PM +0200, Jani Nikula wrote: > > +Knut, Fengguang > > On Fri, 02 Feb 2018, Greg KH <gregkh(a)linuxfoundation.org> wrote: > > - If clang now builds the kernel "cleanly", yes, I want to take > > warning fixes in the stable tree. And even better yet, if you > > keep working to ensure the tree is "clean", that would be > > wonderful. > > So we can run sparse using 'make C=1' and friends, or other static > analysis tools using 'make CHECK=foo C=1', as long as the passed command > line params work. There was work by Knut to extend this make checker > stuff [1]. Since mixing different HOSTCC's in a single workdir seems > like a bad idea, I wonder how hard it would be to make clang work like > this: > > $ make CHECK=clang C=1 > > Or using Knut's wrapper. Feels like that could increase the use of clang > for static analysis of patches. Why not just build with clang itself: make CC=clang thanks, greg k-h

2 1

Re: clang warning: implicit conversion in intel_ddi.c:1481
by Lukas Bulwahn Feb. 2, 2018

Feb. 2, 2018

On Fri, 2 Feb 2018, Jani Nikula wrote: > Being brutally honest, please write shorter reports and shorter emails > to the lists. > > The static analysis reports are welcome, but only when 1) we didn't > already fix it in linux-next, or 2) it reveals an actual bug, not just a > warning, warranting a backport. That will be our policy. Lukas

4 3

[usb-serial] Support for console read from usb serial driver
by Ivid Suvarna Feb. 1, 2018

Feb. 1, 2018

Hi All, I was going through usb serial driver console related source code (drivers/usb/serial/console.c) in linux kernel and came across "usb_console_write" function and was wondering if any usb serial convertor drivers were using this function? If so any pointers on how it is being used? Also can we implement something like "usb_console_read" which can be useful for interactive debugging like in kgdb. I saw kgdb using something like "poll_get_char and poll_put_char". I found them in most of serial drivers like 8250 and so on. I am using pl2303 usb to serial convertor for getting a serial console. Is there any way to implement something like usb_console_read in usb serial drivers? Can you guys give me some pointers on this. Thanks, IVID

2 1

Re: [perf] perf probe fails sometimes on 4.9
by Pintu Kumar Feb. 1, 2018

Feb. 1, 2018

Dear Masami, Now I am stuck again with 'perf test' failure on 4.9 # perf --version perf version 4.9.20-<product name> # perf test 16: Try 'import perf' in python, checking link problems : FAILED! 37.2: Test BPF prologue generation : FAILED! If you have any clue about these failure please hep me. Here are the verbose output: ----------------------------------------------------------------------------- 1) # perf test python -v 16: Try 'import perf' in python, checking link problems : --- start --- test child forked, pid 24562 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! ------------------------------------------------------------------------------ 2) # perf test BPF -v ------------------------------------------------------------------------------- ..... bpf: config 'func=null_lseek file->f_mode offset orig' is ok 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 31, 2018 at 9:01 AM, Masami Hiramatsu <mhiramat(a)kernel.org> wrote: > On Tue, 30 Jan 2018 19:20:36 +0530 > Pintu Kumar <pintu.ping(a)gmail.com> wrote: > >> On Tue, Jan 30, 2018 at 11:13 AM, Masami Hiramatsu <mhiramat(a)kernel.org> wrote: >> > >> > On Mon, 29 Jan 2018 22:00:52 +0530 >> > Pintu Kumar <pintu.ping(a)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(a)kernel.org> wrote: >> > > > On Mon, 29 Jan 2018 13:40:34 +0530 >> > > > Pintu Kumar <pintu.ping(a)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? >> > >> >> Yes these functions are present in kallsyms. >> >> # cat /proc/kallsyms | grep -w schedule ; cat /proc/kallsyms | grep -w _etext >> ffffffff829328e0 T schedule >> ffffffff8293e751 T _etext >> >> >> > > 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. >> > >> >> Fortunately or unfortunately, now it is passing every time. >> Still not sure about the cause. >> If it fails again, I will collect info with -v and report again. >> Any specific info that I need to check when it fails ? > > OK, if you hit it again, please run perf-probe with -vvv option > (-v is enough usually, if it is unknown bug, -vvv will be better) > > Thank you, > > >> >> Thank You, >> Pintu >> >> >> > Thank you, >> > >> > > >> > > >> > > > Thank you, >> > > > >> > > > >> > > >> >> > > >> >> > > >> Thank You! >> > > >> Regards, >> > > >> Pintu >> > > >> >> > > >> >> > > >> On Thu, Jan 25, 2018 at 7:09 PM, Pintu Kumar <pintu.ping(a)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(a)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(a)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(a)kernel.org> >> > >> > >> > -- >> > Masami Hiramatsu <mhiramat(a)kernel.org> > > > -- > Masami Hiramatsu <mhiramat(a)kernel.org>

1 1

Re: Mark dma buffer readonly
by Rohan Puri Jan. 31, 2018

Jan. 31, 2018

On 31-Jan-2018 11:36 PM, "Saket Sinha" <saket.sinha89(a)gmail.com> wrote: > >> However, I am using this in kthreads and I want to protect it without >> using mutex/spilock. >> Apart from protecting it with spinlock or mutex, is their anyway to >> mark this dma buffer as read-only so that other threads(after >> concerned thread has accessed it) cannot access the dma buffer. > > Basic locking theory states that if one section of code is already using one > type of locking primitive, and you want a lock on the resource, you need to > use the same type of lock, and the same instance. > I just love this above sentence, well put in a general sense, Valdis. > In other words, you need to use a spinlock on dma_spin_lock as well, or > things *will* fail (and when it's a DMA controller in question, the failure will > almost certainly be spectacular). So using a mutex is probably out of > the question. > > Have you considered restructuring your code so a spinlock is usable? > Thanks Valdis for the prompt reply. I would go ahead and check if spinlock could work instead of mutex which I am currently using. However, let me also explain the context how I am using mutex by below pseudo code- MUTEX_INIT(dma_lock); void dummy_worker_thread() { ................... mutex_lock(&dma_lock) CHECK_BIT(hw_register, nth_bit); mutex_unlock(&dma_lock); .................... } Lets suppose the nth_bit is set in hw_register every X ms. Do you think spinlock will be more advantageous here than mutex ? See basic difference between mutex and spinlock is, the former puts the thread waiting on the lock to sleep and later does a busy wait. Since the nth bit is set every X ms, I think sleeping and waking up would turn out to be costly operations/overhead so no mutex. Spinlock would be good enough here. Note: I am on ARMv8 SMP system using kernel version 4.4 . Regards, Saket Sinha Regards, Saket Sinha _______________________________________________ Kernelnewbies mailing list Kernelnewbies(a)kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies - Rohan

2 1

Mark dma buffer readonly
by Saket Sinha Jan. 31, 2018

Jan. 31, 2018

Hi, This is regarding dma memory usage in my kernel driver on arm64 processor. I have a structure in my kernel driver as shown below- struct dummy_dc_dmabuf { struct dma_buf *buf; struct dma_buf_attachment *attach; struct sg_table *sgt; }; For this I am able to get memory allocated like below void pin_window(struct dummy_dmabuf **dum_buf, int fd, struct device *dev) { struct dummy_dmabuf *dum_dmabuf; dma_addr_t dma_addr; dum_dmabuf = kzalloc(sizeof(*dum_dmabuf), GFP_KERNEL); if (!dum_dmabuf) return -ENOMEM; dum_dmabuf->buf = dma_buf_get(fd); dum_dmabuf->attach = dma_buf_attach(dum_dmabuf->buf, dev->parent); dum_dmabuf->sgt = dma_buf_map_attachment(dum_dmabuf->attach, DMA_TO_DEVICE); *dum_buf = dum_dmabuf; } As per ldd3 , Chapter 15 - "The DMA controller is a shared resource, and confusion could arise if more than one processor attempts to program it simultaneously. For that reason, the controller is protected by a spinlock, called dma_spin_lock. Drivers should not manipulate the lock directly;" However, I am using this in kthreads and I want to protect it without using mutex/spilock. Apart from protecting it with spinlock or mutex, is their anyway to mark this dma buffer as read-only so that other threads(after concerned thread has accessed it) cannot access the dma buffer. Regards, Saket Sinha

2 2

Re: [perf] perf probe fails sometimes on 4.9
by Pintu Kumar Jan. 31, 2018

Jan. 31, 2018

On Tue, Jan 30, 2018 at 11:13 AM, Masami Hiramatsu <mhiramat(a)kernel.org> wrote: > > On Mon, 29 Jan 2018 22:00:52 +0530 > Pintu Kumar <pintu.ping(a)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(a)kernel.org> wrote: > > > On Mon, 29 Jan 2018 13:40:34 +0530 > > > Pintu Kumar <pintu.ping(a)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? > Yes these functions are present in kallsyms. # cat /proc/kallsyms | grep -w schedule ; cat /proc/kallsyms | grep -w _etext ffffffff829328e0 T schedule ffffffff8293e751 T _etext > > 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. > Fortunately or unfortunately, now it is passing every time. Still not sure about the cause. If it fails again, I will collect info with -v and report again. Any specific info that I need to check when it fails ? Thank You, Pintu > Thank you, > > > > > > > > Thank you, > > > > > > > > >> > > >> > > >> Thank You! > > >> Regards, > > >> Pintu > > >> > > >> > > >> On Thu, Jan 25, 2018 at 7:09 PM, Pintu Kumar <pintu.ping(a)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(a)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(a)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(a)kernel.org> > > > -- > Masami Hiramatsu <mhiramat(a)kernel.org>

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Re: [perf] perf probe fails sometimes on 4.9
by Pintu Kumar Jan. 30, 2018

Jan. 30, 2018

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(a)kernel.org> wrote: > On Mon, 29 Jan 2018 13:40:34 +0530 > Pintu Kumar <pintu.ping(a)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. I still needs to figure out, in which condition it works and which condition it fails. Usually I noticed that in fresh reboot case it works. > Thank you, > > >> >> >> Thank You! >> Regards, >> Pintu >> >> >> On Thu, Jan 25, 2018 at 7:09 PM, Pintu Kumar <pintu.ping(a)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(a)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(a)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(a)kernel.org>

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Re: [perf] perf probe fails sometimes on 4.9
by Pintu Kumar Jan. 29, 2018

Jan. 29, 2018

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. Note: I don't have CONFIG_DEBUG_INFO enabled in kernel. Is this the problem? However, I manually copied the vmlinux file to /boot/ directory, but still it does not work. 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. Thank You! Regards, Pintu On Thu, Jan 25, 2018 at 7:09 PM, Pintu Kumar <pintu.ping(a)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(a)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(a)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 >>> >>> >>>

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