Re: 4.9.208 regression in perf building

[Akemi Yagi]

Adding Arnaldo and Jiri to the CC list.

On Sun, Jan 5, 2020 at 9:01 AM Gordan Bobic <gordan@xxxxxxxxxxxxx> wrote:
>
> It looks like 4.9.208 introduces a build regression for perf:
>
> make -f /builddir/build/BUILD/kernel-4.9.208/linux-4.9.208-1.el7.x86_64/tools/build/Makefile.build
> dir=. obj=perf

>  -c -o builtin-report.o builtin-report.c
> builtin-report.c: In function âreport__setup_sample_typeâ:
> builtin-report.c:296:6: error: âdwarf_callchain_usersâ undeclared
> (first use in this function)
>   if (dwarf_callchain_users) {
>       ^
> builtin-report.c:296:6: note: each undeclared identifier is reported
> only once for each function it appears in
> mv: cannot stat â./.builtin-report.o.tmpâ: No such file or directory
> make[3]: *** [builtin-report.o] Error 1
> make[2]: *** [perf-in.o] Error 2
> make[1]: *** [sub-make] Error 2
> make: *** [all] Error 2
>
> 4,9.207 works fine.

The regression was caused by the following patch:

https://lore.kernel.org/lkml/20191021133834.25998-7-acme@xxxxxxxxxx/

To fix this, 'dwarf_callchain_users' needs to be declared.

Akemi