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linux/samples/bpf/test_overhead_tp.bpf.c

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samples/bpf: add tracepoint vs kprobe performance tests 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 <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07 09:43:31 +08:00
/* Copyright (c) 2016 Facebook
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
samples/bpf: use vmlinux.h instead of implicit headers in BPF test program This commit applies vmlinux.h to BPF functionality testing program. Macros that were not defined despite migration to "vmlinux.h" were defined separately in individual files. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Link: https://lore.kernel.org/r/20230115071613.125791-10-danieltimlee@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-15 15:16:12 +08:00
#include "vmlinux.h"
samples/bpf: Use consistent include paths for libbpf 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 <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk
2020-01-20 21:06:49 +08:00
#include <bpf/bpf_helpers.h>
samples/bpf: add tracepoint vs kprobe performance tests 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 <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07 09:43:31 +08:00
bpf: use canonical ftrace path The canonical location for the tracefs filesystem is at /sys/kernel/tracing. But, from Documentation/trace/ftrace.rst: Before 4.1, all ftrace tracing control files were within the debugfs file system, which is typically located at /sys/kernel/debug/tracing. For backward compatibility, when mounting the debugfs file system, the tracefs file system will be automatically mounted at: /sys/kernel/debug/tracing Many comments and samples in the bpf code still refer to this older debugfs path, so let's update them to avoid confusion. There are a few spots where the bpf code explicitly checks both tracefs and debugfs (tools/bpf/bpftool/tracelog.c and tools/lib/api/fs/fs.c) and I've left those alone so that the tools can continue to work with both paths. Signed-off-by: Ross Zwisler <zwisler@google.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20230313205628.1058720-2-zwisler@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-14 04:56:27 +08:00
/* from /sys/kernel/tracing/events/task/task_rename/format */
samples/bpf: add tracepoint vs kprobe performance tests 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 <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07 09:43:31 +08:00
SEC("tracepoint/task/task_rename")
samples/bpf: convert to vmlinux.h with tracing programs This commit replaces separate headers with a single vmlinux.h to tracing programs. Thanks to that, we no longer need to define the argument structure for tracing programs directly. For example, argument for the sched_switch tracpepoint (sched_switch_args) can be replaced with the vmlinux.h provided trace_event_raw_sched_switch. Additional defines have been added to the BPF program either directly or through the inclusion of net_shared.h. Defined values are PERF_MAX_STACK_DEPTH, IFNAMSIZ constants and __stringify() macro. This change enables the BPF program to access internal structures with BTF generated "vmlinux.h" header. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Link: https://lore.kernel.org/r/20230818090119.477441-3-danieltimlee@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-18 17:01:12 +08:00
int prog(struct trace_event_raw_task_rename *ctx)
samples/bpf: add tracepoint vs kprobe performance tests 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 <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07 09:43:31 +08:00
{
return 0;
}
bpf: use canonical ftrace path The canonical location for the tracefs filesystem is at /sys/kernel/tracing. But, from Documentation/trace/ftrace.rst: Before 4.1, all ftrace tracing control files were within the debugfs file system, which is typically located at /sys/kernel/debug/tracing. For backward compatibility, when mounting the debugfs file system, the tracefs file system will be automatically mounted at: /sys/kernel/debug/tracing Many comments and samples in the bpf code still refer to this older debugfs path, so let's update them to avoid confusion. There are a few spots where the bpf code explicitly checks both tracefs and debugfs (tools/bpf/bpftool/tracelog.c and tools/lib/api/fs/fs.c) and I've left those alone so that the tools can continue to work with both paths. Signed-off-by: Ross Zwisler <zwisler@google.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20230313205628.1058720-2-zwisler@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-14 04:56:27 +08:00
/* from /sys/kernel/tracing/events/fib/fib_table_lookup/format */
samples/bpf: replace broken overhead microbenchmark with fib_table_lookup The test_overhead bpf program is designed to compare performance between tracepoint and kprobe. Initially it used task_rename and urandom_read tracepoint. However, commit 14c174633f34 ("random: remove unused tracepoints") removed urandom_read tracepoint, and for this reason the test_overhead got broken. This commit introduces new microbenchmark using fib_table_lookup. This microbenchmark sends UDP packets to localhost in order to invoke fib_table_lookup. In a nutshell: fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); addr.sin_addr.s_addr = inet_addr(DUMMY_IP); addr.sin_port = htons(DUMMY_PORT); for() { sendto(fd, buf, strlen(buf), 0, (struct sockaddr *)&addr, sizeof(addr)); } on 4 cpus in parallel: lookup per sec base (no tracepoints, no kprobes) 381k with kprobe at fib_table_lookup() 325k with tracepoint at fib:fib_table_lookup 330k with raw_tracepoint at fib:fib_table_lookup 365k Fixes: 14c174633f34 ("random: remove unused tracepoints") Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Link: https://lore.kernel.org/r/20230115071613.125791-6-danieltimlee@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-15 15:16:08 +08:00
SEC("tracepoint/fib/fib_table_lookup")
samples/bpf: convert to vmlinux.h with tracing programs This commit replaces separate headers with a single vmlinux.h to tracing programs. Thanks to that, we no longer need to define the argument structure for tracing programs directly. For example, argument for the sched_switch tracpepoint (sched_switch_args) can be replaced with the vmlinux.h provided trace_event_raw_sched_switch. Additional defines have been added to the BPF program either directly or through the inclusion of net_shared.h. Defined values are PERF_MAX_STACK_DEPTH, IFNAMSIZ constants and __stringify() macro. This change enables the BPF program to access internal structures with BTF generated "vmlinux.h" header. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Link: https://lore.kernel.org/r/20230818090119.477441-3-danieltimlee@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-18 17:01:12 +08:00
int prog2(struct trace_event_raw_fib_table_lookup *ctx)
samples/bpf: add tracepoint vs kprobe performance tests 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 <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07 09:43:31 +08:00
{
return 0;
}
char _license[] SEC("license") = "GPL";
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