Add ability to filter top B results, both in replay/verifier mode and
comparison mode. Just adding `-n10` will emit only first 10 rows, or
less, if there is not enough rows.
This is not just a shortcut instead of passing veristat output through
`head`, though. Filtering out all the other rows influences final table
formatting, as table column widths are calculated based on actual
emitted test.
To demonstrate the difference, compare two "equivalent" forms below, one
using head and another using -n argument.
TOP N FEATURE
=============
[vmuser@archvm bpf]$ sudo ./veristat -C ~/baseline-results-selftests.csv ~/sanity2-results-selftests.csv -e file,prog,insns,states -s '|insns_diff|' -n10
File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF)
---------------------------------------- --------------------- --------- --------- ------------ ---------- ---------- -------------
test_seg6_loop.bpf.linked3.o __add_egr_x 12440 12360 -80 (-0.64%) 364 357 -7 (-1.92%)
async_stack_depth.bpf.linked3.o async_call_root_check 145 145 +0 (+0.00%) 3 3 +0 (+0.00%)
async_stack_depth.bpf.linked3.o pseudo_call_check 139 139 +0 (+0.00%) 3 3 +0 (+0.00%)
atomic_bounds.bpf.linked3.o sub 7 7 +0 (+0.00%) 0 0 +0 (+0.00%)
bench_local_storage_create.bpf.linked3.o kmalloc 5 5 +0 (+0.00%) 0 0 +0 (+0.00%)
bench_local_storage_create.bpf.linked3.o sched_process_fork 22 22 +0 (+0.00%) 2 2 +0 (+0.00%)
bench_local_storage_create.bpf.linked3.o socket_post_create 23 23 +0 (+0.00%) 2 2 +0 (+0.00%)
bind4_prog.bpf.linked3.o bind_v4_prog 358 358 +0 (+0.00%) 33 33 +0 (+0.00%)
bind6_prog.bpf.linked3.o bind_v6_prog 429 429 +0 (+0.00%) 37 37 +0 (+0.00%)
bind_perm.bpf.linked3.o bind_v4_prog 15 15 +0 (+0.00%) 1 1 +0 (+0.00%)
PIPING TO HEAD
==============
[vmuser@archvm bpf]$ sudo ./veristat -C ~/baseline-results-selftests.csv ~/sanity2-results-selftests.csv -e file,prog,insns,states -s '|insns_diff|' | head -n12
File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF)
----------------------------------------------------- ---------------------------------------------------- --------- --------- ------------ ---------- ---------- -------------
test_seg6_loop.bpf.linked3.o __add_egr_x 12440 12360 -80 (-0.64%) 364 357 -7 (-1.92%)
async_stack_depth.bpf.linked3.o async_call_root_check 145 145 +0 (+0.00%) 3 3 +0 (+0.00%)
async_stack_depth.bpf.linked3.o pseudo_call_check 139 139 +0 (+0.00%) 3 3 +0 (+0.00%)
atomic_bounds.bpf.linked3.o sub 7 7 +0 (+0.00%) 0 0 +0 (+0.00%)
bench_local_storage_create.bpf.linked3.o kmalloc 5 5 +0 (+0.00%) 0 0 +0 (+0.00%)
bench_local_storage_create.bpf.linked3.o sched_process_fork 22 22 +0 (+0.00%) 2 2 +0 (+0.00%)
bench_local_storage_create.bpf.linked3.o socket_post_create 23 23 +0 (+0.00%) 2 2 +0 (+0.00%)
bind4_prog.bpf.linked3.o bind_v4_prog 358 358 +0 (+0.00%) 33 33 +0 (+0.00%)
bind6_prog.bpf.linked3.o bind_v6_prog 429 429 +0 (+0.00%) 37 37 +0 (+0.00%)
bind_perm.bpf.linked3.o bind_v4_prog 15 15 +0 (+0.00%) 1 1 +0 (+0.00%)
Note all the wasted whitespace in the "PIPING TO HEAD" variant.
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
tools/testing/selftests/bpf/veristat.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/tools/testing/selftests/bpf/veristat.c b/tools/testing/selftests/bpf/veristat.c
index 102914f70573..443a29fc6a62 100644
--- a/tools/testing/selftests/bpf/veristat.c
+++ b/tools/testing/selftests/bpf/veristat.c
@@ -149,6 +149,7 @@ static struct env {
bool show_version;
bool comparison_mode;
bool replay_mode;
+ int top_n;
int log_level;
int log_size;
@@ -215,6 +216,7 @@ static const struct argp_option opts[] = {
{ "log-size", OPT_LOG_SIZE, "BYTES", 0, "Customize verifier log size (default to 16MB)" },
{ "test-states", 't', NULL, 0,
"Force frequent BPF verifier state checkpointing (set BPF_F_TEST_STATE_FREQ program flag)" },
+ { "top-n", 'n', "N", 0, "Emit only up to first N results." },
{ "quiet", 'q', NULL, 0, "Quiet mode" },
{ "emit", 'e', "SPEC", 0, "Specify stats to be emitted" },
{ "sort", 's', "SPEC", 0, "Specify sort order" },
@@ -293,6 +295,14 @@ static error_t parse_arg(int key, char *arg, struct argp_state *state)
case 't':
env.force_checkpoints = true;
break;
+ case 'n':
+ errno = 0;
+ env.top_n = strtol(arg, NULL, 10);
+ if (errno) {
+ fprintf(stderr, "invalid top N specifier: %s\n", arg);
+ argp_usage(state);
+ }
+ break;
case 'C':
env.comparison_mode = true;
break;
--
2.34.1
