lkml.org 
[lkml]   [2015]   [Nov]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: perf BPF/elfdep intermitent build problems


On 2015/11/19 10:21, Wangnan (F) wrote:
>
>
> On 2015/11/19 9:24, Wangnan (F) wrote:
>>
>>
>> On 2015/11/19 6:44, Arnaldo Carvalho de Melo wrote:
>>> Have you guys ever saw this?
>>>
>>> [acme@zoo linux]$ alias m
>>> alias m='perf stat -e cycles make O=/tmp/build/perf -C tools/perf
>>> install-bin'
>>> [acme @zoo linux]$ m
>>> make: Entering directory '/home/git/linux/tools/perf'
>>> BUILD: Doing 'make -j4' parallel build
>>> make[2]: Nothing to be done for 'fixdep'.
>>> CC /tmp/build/perf/util/machine.o
>>> LD /tmp/build/perf/util/libperf-in.o
>>> No libelf found
>>> BPF API too old
>>
>> This error message means the kernel header in rootfs is too old,
>> causes tools/build/feature/test-bpf.c failed to be built.
>
> Strange... even in feature detection it should check BPF API through
> kernel source where you are using to build perf...
>
> I guess you are not using NFS or share it with other people?
>
>>
>>> Makefile:191: recipe for target 'elfdep' failed
>>> make[2]: *** [elfdep] Error 255
>>> make[2]: *** Waiting for unfinished jobs....
>>> Makefile:194: recipe for target 'bpfdep' failed
>>> make[2]: *** [bpfdep] Error 255
>>> Makefile.perf:434: recipe for target '/tmp/build/perf/libbpf.a' failed
>>> make[1]: *** [/tmp/build/perf/libbpf.a] Error 2
>>> make[1]: *** Waiting for unfinished jobs....
>>> LD /tmp/build/perf/libperf-in.o
>>> Makefile:87: recipe for target 'install-bin' failed
>>> make: *** [install-bin] Error 2
>>> make: Leaving directory '/home/git/linux/tools/perf'
>>>
>>> Performance counter stats for 'make O=/tmp/build/perf -C tools/perf
>>> install-bin':
>>>
>>> 10,265,920,369 cycles
>>>
>>> 3.002799545 seconds time elapsed
>>>
>>> [acme@zoo linux]$
>>>
>>>
>>> If I go and try doing a clean on the libbpf dir I see another problem:
>>>
>>> [acme@zoo linux]$ cd tools/lib/bpf
>>> [acme@zoo bpf]$ make clean
>>>
>>> Auto-detecting system features:
>>> ... libelf: [ OFF ]
>>> ... bpf: [ OFF ]
>>>
>>> CLEAN libbpf
>>> CLEAN core-gen
>>> [acme@zoo bpf]$
>>>
>>> No need for feature detection when doing a plain 'make clean', right?
>>>
>
> Right. It should be
>
> $ cd tools/lib/bpf
> $ make clean
> CLEAN libbpf
> CLEAN core-gen
> $
>
>
> After cleaning can you trigger this problem again?
>

Tiggered part of your problem:

$ make

Auto-detecting system features:
... libelf: [ on ]
... bpf: [ on ]

CC libbpf.o
CC bpf.o
LD libbpf-in.o
LINK libbpf.a
LINK libbpf.so
$ make clean
CLEAN libbpf
CLEAN core-gen
$ make clean

Auto-detecting system features:
... libelf: [ on ]
... bpf: [ on ]

CLEAN libbpf
CLEAN core-gen

Feature check would be triggered the second time we make clean.

Will look into it.

Thank you.





\
 
 \ /
  Last update: 2015-11-19 03:41    [W:0.061 / U:4.080 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site