linux-toradex.git/samples/bpf/offwaketime_kern.c, branch v5.16

samples/bpf: Define MAX_ENTRIES instead of a magic number in offwaketime

2021-08-15T07:08:40+00:00

Define MAX_ENTRIES instead of using 10000 as a magic number in various
places.

Signed-off-by: Muhammad Falak R Wani 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20210815065013.15411-1-falakreyaz@gmail.com

samples: bpf: Refactor tracepoint tracing programs with libbpf

2020-08-25T03:59:35+00:00

For the problem of increasing fragmentation of the bpf loader programs,
instead of using bpf_loader.o, which is used in samples/bpf, this
commit refactors the existing tracepoint tracing programs with libbbpf
bpf loader.

    - Adding a tracepoint event and attaching a bpf program to it was done
    through bpf_program_attach().
    - Instead of using the existing BPF MAP definition, MAP definition
    has been refactored with the new BTF-defined MAP format.

Signed-off-by: Daniel T. Lee 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20200823085334.9413-4-danieltimlee@gmail.com

samples/bpf, selftests/bpf: Use bpf_probe_read_kernel

2020-07-21T20:26:26+00:00

A handful of samples and selftests fail to build on s390, because
after commit 0ebeea8ca8a4 ("bpf: Restrict bpf_probe_read{, str}()
only to archs where they work") bpf_probe_read is not available
anymore.

Fix by using bpf_probe_read_kernel.

Signed-off-by: Ilya Leoshkevich 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20200720114806.88823-1-iii@linux.ibm.com

samples/bpf: Remove compiler warnings

2020-05-13T19:30:50+00:00

Commit 5fbc220862fc ("tools/libpf: Add offsetof/container_of macro
in bpf_helpers.h") added macros offsetof/container_of to
bpf_helpers.h. Unfortunately, it caused compilation warnings
below for a few samples/bpf programs:
  In file included from /data/users/yhs/work/net-next/samples/bpf/sockex2_kern.c:4:
  In file included from /data/users/yhs/work/net-next/include/uapi/linux/in.h:24:
  In file included from /data/users/yhs/work/net-next/include/linux/socket.h:8:
  In file included from /data/users/yhs/work/net-next/include/linux/uio.h:8:
  /data/users/yhs/work/net-next/include/linux/kernel.h:992:9: warning: 'container_of' macro redefined [-Wmacro-redefined]
          ^
  /data/users/yhs/work/net-next/tools/lib/bpf/bpf_helpers.h:46:9: note: previous definition is here
          ^
  1 warning generated.
    CLANG-bpf  samples/bpf/sockex3_kern.o

In all these cases, bpf_helpers.h is included first, followed by other
standard headers. The macro container_of is defined unconditionally
in kernel.h, causing the compiler warning.

The fix is to move bpf_helpers.h after standard headers.

Signed-off-by: Yonghong Song 
Signed-off-by: Alexei Starovoitov 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20200513180223.2949987-1-yhs@fb.com

samples/bpf: Use consistent include paths for libbpf

2020-01-21T00:37:45+00:00

Fix all files in samples/bpf to include libbpf header files with the bpf/
prefix, to be consistent with external users of the library. Also ensure
that all includes of exported libbpf header files (those that are exported
on 'make install' of the library) use bracketed includes instead of quoted.

To make sure no new files are introduced that doesn't include the bpf/
prefix in its include, remove tools/lib/bpf from the include path entirely,
and use tools/lib instead.

Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Alexei Starovoitov 
Acked-by: Jesper Dangaard Brouer 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk

selftests/bpf: Split off tracing-only helpers into bpf_tracing.h

2019-10-08T21:16:03+00:00

Split-off PT_REGS-related helpers into bpf_tracing.h header. Adjust
selftests and samples to include it where necessary.

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Acked-by: John Fastabend 
Acked-by: Song Liu 
Link: https://lore.kernel.org/bpf/20191008175942.1769476-5-andriin@fb.com

bpf, samples: don't zero data when not needed

2016-04-15T01:40:42+00:00

Remove the zero initialization in the sample programs where appropriate.
Note that this is an optimization which is now possible, old programs
still doing the zero initialization are just fine as well. Also, make
sure we don't have padding issues when we don't memset() the entire
struct anymore.

Signed-off-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

samples/bpf: tracepoint example

2016-04-08T01:04:27+00:00

modify offwaketime to work with sched/sched_switch tracepoint
instead of kprobe into finish_task_switch

Signed-off-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

samples/bpf: offwaketime example

2016-02-20T05:21:44+00:00

This is simplified version of Brendan Gregg's offwaketime:
This program shows kernel stack traces and task names that were blocked and
"off-CPU", along with the stack traces and task names for the threads that woke
them, and the total elapsed time from when they blocked to when they were woken
up. The combined stacks, task names, and total time is summarized in kernel
context for efficiency.

Example:
$ sudo ./offwaketime | flamegraph.pl > demo.svg
Open demo.svg in the browser as FlameGraph visualization.

Signed-off-by: Alexei Starovoitov 
Signed-off-by: David S. Miller