linux_dsm_epyc7002/tools
Andrii Nakryiko 783b8f01f5 libbpf: Don't attach perf_buffer to offline/missing CPUs
It's quite common on some systems to have more CPUs enlisted as "possible",
than there are (and could ever be) present/online CPUs. In such cases,
perf_buffer creationg will fail due to inability to create perf event on
missing CPU with error like this:

libbpf: failed to open perf buffer event on cpu #16: No such device

This patch fixes the logic of perf_buffer__new() to ignore CPUs that are
missing or currently offline. In rare cases where user explicitly listed
specific CPUs to connect to, behavior is unchanged: libbpf will try to open
perf event buffer on specified CPU(s) anyways.

Fixes: fb84b82246 ("libbpf: add perf buffer API")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191212013609.1691168-1-andriin@fb.com
2019-12-13 13:00:09 -08:00
..
accounting
arch perf/core improvements and fixes: 2019-11-29 06:56:05 +01:00
bpf tools, bpf: Fix build for 'make -s tools/bpf O=<dir>' 2019-11-24 16:58:45 -08:00
build perf tools: Allow to link with libbpf dynamicaly 2019-11-26 11:17:45 -03:00
cgroup
debugging
firewire
firmware
gpio tools: gpio: Correctly add make dependencies for gpio_utils 2019-11-13 13:46:04 +01:00
hv tools: hv: add vmbus testing tool 2019-11-21 20:10:44 -05:00
iio
include Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 15:04:47 -08:00
io_uring
kvm/kvm_stat
laptop
leds
lib libbpf: Don't attach perf_buffer to offline/missing CPUs 2019-12-13 13:00:09 -08:00
memory-model
nfsd
objtool Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 15:04:47 -08:00
pci
pcmcia
perf Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2019-12-02 10:50:29 -08:00
power platform-drivers-x86 for v5.5-1 2019-12-01 18:24:25 -08:00
scripts
spi
testing selftests/bpf: Add CPU mask parsing tests 2019-12-13 12:59:55 -08:00
thermal/tmon
time
usb
virtio
vm
wmi
Makefile