On Thu, 12 Dec 2019 at 07:05, Andrii Nakryiko <andriin@xxxxxx> wrote: > > This patch set fixes perf_buffer__new() behavior on systems which have some of > the CPUs offline/missing (due to difference between "possible" and "online" > sets). perf_buffer will create per-CPU buffer and open/attach to corresponding > perf_event only on CPUs present and online at the moment of perf_buffer > creation. Without this logic, perf_buffer creation has no chances of > succeeding on such systems, preventing valid and correct BPF applications from > starting. > > Andrii Nakryiko (4): > libbpf: extract and generalize CPU mask parsing logic > selftests/bpf: add CPU mask parsing tests > libbpf: don't attach perf_buffer to offline/missing CPUs perf build failed on stable-rc 5.5 branch. libbpf.c: In function '__perf_buffer__new': libbpf.c:6159:8: error: implicit declaration of function 'parse_cpu_mask_file'; did you mean 'parse_uint_from_file'? [-Werror=implicit-function-declaration] err = parse_cpu_mask_file(online_cpus_file, &online, &n); ^~~~~~~~~~~~~~~~~~~ parse_uint_from_file libbpf.c:6159:8: error: nested extern declaration of 'parse_cpu_mask_file' [-Werror=nested-externs] build log, https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-stable-rc-5.5/DISTRO=lkft,MACHINE=hikey,label=docker-lkft/11/console -- Linaro LKFT https://lkft.linaro.org