Re: Documentation bug in kernelnewbies.org/StartKernelHacking
On Wed, Jan 24, 2018 at 09:40:30PM -0500, Christopher Díaz Riveros wrote: > Hi, I was reading the StartKernelHacking section from kernelnewbies.org > site and found that the command: > > scripts/checkpatch.pl --terse --show-types --strict path/to/source/file > > needs to add the --file option before path/to..., if not, checkpatch.pl > will complain about the non-diff format. fixed. thanks Tobin ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: clang warning: implicit conversion in intel_ddi.c:1481
> > We are interested who is we? ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: [perf] perf test BPF fails on 4.9.20
On Mon, Feb 5, 2018 at 7:24 PM, Masami Hiramatsu wrote: > On Mon, 5 Feb 2018 15:17:41 +0530 > Pintu Kumar wrote: > >> On Sat, Feb 3, 2018 at 6:49 PM, Masami Hiramatsu wrote: >> > Hi Pintu, >> > >> > On Fri, 2 Feb 2018 19:03:30 +0530 >> > Pintu Kumar wrote: >> > >> >> Hi All, >> >> >> >> I have fixed both the issue with perf test. >> >> >> >> 1) 16: Try 'import perf' in python, checking link problems : FAILED! >> >> To fix this issue, I have to install: >> >> pip install --upgrade pip >> >> pip2.7 install perf >> >> >> >> 2) 37.2: Test BPF prologue generation : FAILED! >> >> To fix this issue I had to enable full version of CONFIG_DEBUG_INFO in >> >> kernel. >> >> >> >> Now, my question is: >> >> Is it possible to pass BPF test without enabling CONFIG_DEBUG_INFO in >> >> kernel ? >> > >> > It depends on what BPF test does, but it seems to access local vars. This >> > means >> > you need to enable CONFIG_DEBUG_INFO. With debuginfo we can find the >> > assignment >> > of register/stack for each local variable. >> > >> >> OK. Thank you so much for your reply. >> I think we don't need BPF test at this time. >> Is it possible to disable/skip it ? > > It depends on what you want to do with perf. If you don't use BPF, yes, you > can > skip it :) > Yes I want to skip the BPF. What is the best way to skip it. I found out that by commenting 'bpf' under : tools/build/Makefile.feature -> FEATURE_TESTS_BASIC, I can turn BPF feature OFF during compilation. However, I still need to execute BPF test and check, if it skips. Is this good enough ? > Thank you, > > -- > Masami Hiramatsu ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: [perf] perf test BPF fails on 4.9.20
On Mon, 5 Feb 2018 15:17:41 +0530 Pintu Kumar wrote: > On Sat, Feb 3, 2018 at 6:49 PM, Masami Hiramatsu wrote: > > Hi Pintu, > > > > On Fri, 2 Feb 2018 19:03:30 +0530 > > Pintu Kumar wrote: > > > >> Hi All, > >> > >> I have fixed both the issue with perf test. > >> > >> 1) 16: Try 'import perf' in python, checking link problems : FAILED! > >> To fix this issue, I have to install: > >> pip install --upgrade pip > >> pip2.7 install perf > >> > >> 2) 37.2: Test BPF prologue generation : FAILED! > >> To fix this issue I had to enable full version of CONFIG_DEBUG_INFO in > >> kernel. > >> > >> Now, my question is: > >> Is it possible to pass BPF test without enabling CONFIG_DEBUG_INFO in > >> kernel ? > > > > It depends on what BPF test does, but it seems to access local vars. This > > means > > you need to enable CONFIG_DEBUG_INFO. With debuginfo we can find the > > assignment > > of register/stack for each local variable. > > > > OK. Thank you so much for your reply. > I think we don't need BPF test at this time. > Is it possible to disable/skip it ? It depends on what you want to do with perf. If you don't use BPF, yes, you can skip it :) Thank you, -- Masami Hiramatsu ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Does uio_pci_generic does not use DMA ?
Hello, I don't find in uio_pci_generic.c any usage of DMA. Is it that the driver does not use DMA in transactions between device and host ? Regards, Ran ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: [perf] perf test BPF fails on 4.9.20
On Sat, Feb 3, 2018 at 6:49 PM, Masami Hiramatsu wrote: > Hi Pintu, > > On Fri, 2 Feb 2018 19:03:30 +0530 > Pintu Kumar wrote: > >> Hi All, >> >> I have fixed both the issue with perf test. >> >> 1) 16: Try 'import perf' in python, checking link problems : FAILED! >> To fix this issue, I have to install: >> pip install --upgrade pip >> pip2.7 install perf >> >> 2) 37.2: Test BPF prologue generation : FAILED! >> To fix this issue I had to enable full version of CONFIG_DEBUG_INFO in >> kernel. >> >> Now, my question is: >> Is it possible to pass BPF test without enabling CONFIG_DEBUG_INFO in kernel >> ? > > It depends on what BPF test does, but it seems to access local vars. This > means > you need to enable CONFIG_DEBUG_INFO. With debuginfo we can find the > assignment > of register/stack for each local variable. > OK. Thank you so much for your reply. I think we don't need BPF test at this time. Is it possible to disable/skip it ? > Thank you, >> >> >> Thanks, >> Pintu >> >> >> On Fri, Feb 2, 2018 at 1:25 PM, Pintu Kumar wrote: >> > Hi, >> > >> > perf test bpf prologue generation is failing. >> > 37.2: Test BPF prologue generation : FAILED! >> > >> > Try to find probe point from debuginfo. >> > Matched function: null_lseek [105be32] >> > Probe point found: null_lseek+0 >> > Searching 'file' variable in context. >> > Converting variable file into trace event. >> > converting f_mode in file >> > file(type:file) has no member f_mode. >> > An error occurred in debuginfo analysis (-22). >> > 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! >> > >> > >> > Is there any fix available for this issue? >> > I searched 4.15, but could not relate any of the patches to this. >> > >> > >> > Thanks, >> > Pintu >> > >> > >> > >> > On Thu, Feb 1, 2018 at 7:34 PM, Pintu Kumar wrote: >> >> Hi, >> >> >> >> After enabling DEBUG_INFO in kernel I still get this error for BPF test. >> >> Please help. >> >> >> >> # perf test BPF -v >> >> . >> >> Looking at the vmlinux_path (8 entries long) >> >> Using >> >> /usr/lib/debug/boot/vmlinux-4.9.00--amd-x86-64-00071-gd94c220-dirty >> >> for symbols >> >> Open Debuginfo file: >> >> /usr/lib/debug/boot/vmlinux-4.9.00--amd-x86-64-00071-gd94c220-dirty >> >> Try to find probe point from debuginfo. >> >> Matched function: null_lseek [105be32] >> >> Probe point found: null_lseek+0 >> >> Searching 'file' variable in context. >> >> Converting variable file into trace event. >> >> converting f_mode in file >> >> file(type:file) has no member f_mode. >> >> An error occurred in debuginfo analysis (-22). >> >> 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! >> >> >> >> >> >> >> >> On Thu, Feb 1, 2018 at 10:50 AM, Pintu Kumar wrote: >> >>> Dear Masami, >> >>> >> >>> Now I am stuck again with 'perf test' failure on 4.9 >> >>> >> >>> # perf --version >> >>> perf version 4.9.20- >> >>> >> >>> # 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 "", line 1, in >> >>> 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 >> >>> wrote: >> On Tue, 30 Jan 2018 19:20:36 +0530 >> Pintu Kumar wrote: >> >> > On Tue, Jan 30, 2018 at 11:13 AM, Masami Hiramatsu >> > wrote: >> > > >> > >
PCI & DMA
Hello, In PCI documentation https://www.mjmwired.net/kernel/Documentation/PCI/pci.txt there is a lot of reference to "DMA". Is it DMA on cpu side or device side ? Best Regards, Ran ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
