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 ‘report__setup_sample_type’: > builtin-report.c:296:6: error: ‘dwarf_callchain_users’ 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 ‘./.builtin-report.o.tmp’: 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