linux-stable.git/samples/bpf/Makefile, branch v4.7.2

samples/bpf: add 'pointer to packet' tests

2016-05-06T20:01:54+00:00

parse_simple.c - packet parser exapmle with single length check that
filters out udp packets for port 9

parse_varlen.c - variable length parser that understand multiple vlan headers,
ipip, ipip6 and ip options to filter out udp or tcp packets on port 9.
The packet is parsed layer by layer with multitple length checks.

parse_ldabs.c - classic style of packet parsing using LD_ABS instruction.
Same functionality as parse_simple.

simple = 24.1Mpps per core
varlen = 22.7Mpps
ldabs  = 21.4Mpps

Parser with LD_ABS instructions is slower than full direct access parser
which does more packet accesses and checks.

These examples demonstrate the choice bpf program authors can make between
flexibility of the parser vs speed.

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

samples/bpf: like LLC also verify and allow redefining CLANG command

2016-04-29T18:26:08+00:00

Users are likely to manually compile both LLVM 'llc' and 'clang'
tools.  Thus, also allow redefining CLANG and verify command exist.

Makefile implementation wise, the target that verify the command have
been generalized.

Signed-off-by: Jesper Dangaard Brouer 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

samples/bpf: allow make to be run from samples/bpf/ directory

2016-04-29T18:25:33+00:00

It is not intuitive that 'make' must be run from the top level
directory with argument "samples/bpf/" to compile these eBPF samples.

Introduce a kbuild make file trick that allow make to be run from the
"samples/bpf/" directory itself.  It basically change to the top level
directory and call "make samples/bpf/" with the "/" slash after the
directory name.

Also add a clean target that only cleans this directory, by taking
advantage of the kbuild external module setting M=$PWD.

Signed-off-by: Jesper Dangaard Brouer 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

samples/bpf: Makefile verify LLVM compiler avail and bpf target is supported

2016-04-29T18:25:32+00:00

Make compiling samples/bpf more user friendly, by detecting if LLVM
compiler tool 'llc' is available, and also detect if the 'bpf' target
is available in this version of LLVM.

Signed-off-by: Jesper Dangaard Brouer 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

samples/bpf: add back functionality to redefine LLC command

2016-04-29T18:25:32+00:00

It is practical to be-able-to redefine the location of the LLVM
command 'llc', because not all distros have a LLVM version with bpf
target support.  Thus, it is sometimes required to compile LLVM from
source, and sometimes it is not desired to overwrite the distros
default LLVM version.

This feature was removed with 128d1514be35 ("samples/bpf: Use llc in
PATH, rather than a hardcoded value").

Add this features back. Note that it is possible to redefine the LLC
on the make command like:

 make samples/bpf/ LLC=~/git/llvm/build/bin/llc

Fixes: 128d1514be35 ("samples/bpf: Use llc in PATH, rather than a hardcoded value")
Signed-off-by: Jesper Dangaard Brouer 
Acked-by: Alexei Starovoitov 
Acked-by: Naveen N. Rao 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-04-09T21:41:41+00:00

samples/bpf: add tracepoint vs kprobe performance tests

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

the first microbenchmark does
fd=open("/proc/self/comm");
for() {
  write(fd, "test");
}
and on 4 cpus in parallel:
                                      writes per sec
base (no tracepoints, no kprobes)         930k
with kprobe at __set_task_comm()          420k
with tracepoint at task:task_rename       730k

For kprobe + full bpf program manully fetches oldcomm, newcomm via bpf_probe_read.
For tracepint bpf program does nothing, since arguments are copied by tracepoint.

2nd microbenchmark does:
fd=open("/dev/urandom");
for() {
  read(fd, buf);
}
and on 4 cpus in parallel:
                                       reads per sec
base (no tracepoints, no kprobes)         300k
with kprobe at urandom_read()             279k
with tracepoint at random:urandom_read    290k

bpf progs attached to kprobe and tracepoint are noop.

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

samples/bpf: Use llc in PATH, rather than a hardcoded value

2016-04-06T20:01:28+00:00

While at it, remove the generation of .s files and fix some typos in the
related comment.

Cc: Alexei Starovoitov 
Cc: David S. Miller 
Cc: Daniel Borkmann 
Cc: Ananth N Mavinakayanahalli 
Cc: Michael Ellerman 
Signed-off-by: Naveen N. Rao 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

samples/bpf: add map performance test

2016-03-09T04:22:03+00:00

performance tests for hash map and per-cpu hash map
with and without pre-allocation

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

samples/bpf: add bpf map stress test

2016-03-09T04:22:02+00:00

this test calls bpf programs from different contexts:
from inside of slub, from rcu, from pretty much everywhere,
since it kprobes all spin_lock functions.
It stresses the bpf hash and percpu map pre-allocation,
deallocation logic and call_rcu mechanisms.
User space part adding more stress by walking and deleting map elements.

Note that due to nature bpf_load.c the earlier kprobe+bpf programs are
already active while loader loads new programs, creates new kprobes and
attaches them.

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