[PATCH 02/28] perf test: Auto bump rlimit(MEMLOCK) for BPF test sake

From: Arnaldo Carvalho de Melo
Date: Mon Jul 15 2019 - 17:12:28 EST


From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

I noticed that the 'perf test bpf' was failing:

# perf test bpf
41: BPF filter :
41.1: Basic BPF filtering : Skip
41.2: BPF pinning : Skip
41.3: BPF prologue generation : Skip
41.4: BPF relocation checker : Skip
# ulimit -l
64
#

Using verbose mode we get just a line bout -EPERF being returned from
libbpf's bpf_load_program_xattr(), that ends up being used in 'perf
test bpf' initial program loading capability query:

Missing basic BPF support, skip this test: Operation not permitted

Not that informative, but on a separate problem when creating BPF maps
bumping rlimit(MEMLOCK) helped, so I tried it here as well, works:

# ulimit -l 128
# perf test bpf
41: BPF filter :
41.1: Basic BPF filtering : Ok
41.2: BPF pinning : Ok
41.3: BPF prologue generation : Ok
41.4: BPF relocation checker : Ok
#

So use the recently added rlimit__bump_memlock() helper:

# ulimit -l 64
# perf test bpf
41: BPF filter :
41.1: Basic BPF filtering : Ok
41.2: BPF pinning : Ok
41.3: BPF prologue generation : Ok
41.4: BPF relocation checker : Ok
# ulimit -l
64
#

I.e. the bumping of memlock is restricted to the 'perf test' instance,
not changing the global value.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: https://lkml.kernel.org/n/tip-b9fubkhr4jm192lu7y8hgjvo@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/tests/builtin-test.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 66a82badc1d1..c3bec9d2c201 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -21,6 +21,7 @@
#include <subcmd/parse-options.h>
#include "string2.h"
#include "symbol.h"
+#include "util/rlimit.h"
#include <linux/kernel.h>
#include <linux/string.h>
#include <subcmd/exec-cmd.h>
@@ -727,6 +728,11 @@ int cmd_test(int argc, const char **argv)

if (skip != NULL)
skiplist = intlist__new(skip);
+ /*
+ * Tests that create BPF maps, for instance, need more than the 64K
+ * default:
+ */
+ rlimit__bump_memlock();

return __cmd_test(argc, argv, skiplist);
}
--
2.21.0