samples/bpf: Use getppid instead of getpgrp for array map stress

Joel Fernandes · davem330 · commit 95ec66968571 · 2017-09-21T11:59:16.000-07:00
When cross-compiling the bpf sample map_perf_test for aarch64, I find that
__NR_getpgrp is undefined. This causes build errors. This syscall is deprecated
and requires defining __ARCH_WANT_SYSCALL_DEPRECATED. To avoid having to define
that, just use a different syscall (getppid) for the array map stress test.

Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Joel Fernandes &lt;joelaf@google.com&gt;
Acked-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/samples/bpf/map_perf_test_kern.c b/samples/bpf/map_perf_test_kern.c
@@ -266,7 +266,7 @@ int stress_hash_map_lookup(struct pt_regs *ctx)
 	return 0;
 }
 
-SEC("kprobe/sys_getpgrp")
+SEC("kprobe/sys_getppid")
 int stress_array_map_lookup(struct pt_regs *ctx)
 {
 	u32 key = 1, i;
diff --git a/samples/bpf/map_perf_test_user.c b/samples/bpf/map_perf_test_user.c
@@ -282,7 +282,7 @@ static void test_array_lookup(int cpu)
 
 	start_time = time_get_ns();
 	for (i = 0; i < max_cnt; i++)
-		syscall(__NR_getpgrp, 0);
+		syscall(__NR_getppid, 0);
 	printf("%d:array_lookup %lld lookups per sec\n",
 	       cpu, max_cnt * 1000000000ll * 64 / (time_get_ns() - start_time));
 }

Original file line number	Diff line number	Diff line change
`@@ -266,7 +266,7 @@ int stress_hash_map_lookup(struct pt_regs *ctx)`
`266`	`266`	`return 0;`
`267`	`267`	`}`
`268`	`268`
`269`		`-SEC("kprobe/sys_getpgrp")`
	`269`	`+SEC("kprobe/sys_getppid")`
`270`	`270`	`int stress_array_map_lookup(struct pt_regs *ctx)`
`271`	`271`	`{`
`272`	`272`	`u32 key = 1, i;`
Original file line number	Diff line number	Diff line change
`@@ -282,7 +282,7 @@ static void test_array_lookup(int cpu)`
`282`	`282`
`283`	`283`	`start_time = time_get_ns();`
`284`	`284`	`for (i = 0; i < max_cnt; i++)`
`285`		`- syscall(__NR_getpgrp, 0);`
	`285`	`+ syscall(__NR_getppid, 0);`
`286`	`286`	`printf("%d:array_lookup %lld lookups per sec\n",`
`287`	`287`	`cpu, max_cnt * 1000000000ll * 64 / (time_get_ns() - start_time));`
`288`	`288`	`}`