samples/bpf: offwaketime example
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 <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index edd638b..c4f8ae0 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -16,6 +16,7 @@
hostprogs-y += tracex6
hostprogs-y += trace_output
hostprogs-y += lathist
+hostprogs-y += offwaketime
test_verifier-objs := test_verifier.o libbpf.o
test_maps-objs := test_maps.o libbpf.o
@@ -32,6 +33,7 @@
tracex6-objs := bpf_load.o libbpf.o tracex6_user.o
trace_output-objs := bpf_load.o libbpf.o trace_output_user.o
lathist-objs := bpf_load.o libbpf.o lathist_user.o
+offwaketime-objs := bpf_load.o libbpf.o offwaketime_user.o
# Tell kbuild to always build the programs
always := $(hostprogs-y)
@@ -47,6 +49,7 @@
always += trace_output_kern.o
always += tcbpf1_kern.o
always += lathist_kern.o
+always += offwaketime_kern.o
HOSTCFLAGS += -I$(objtree)/usr/include
@@ -63,6 +66,7 @@
HOSTLOADLIBES_tracex6 += -lelf
HOSTLOADLIBES_trace_output += -lelf -lrt
HOSTLOADLIBES_lathist += -lelf
+HOSTLOADLIBES_offwaketime += -lelf
# point this to your LLVM backend with bpf support
LLC=$(srctree)/tools/bpf/llvm/bld/Debug+Asserts/bin/llc