Commit 80057b20 authored by Dmitry Safonov's avatar Dmitry Safonov Committed by David S. Miller
Browse files

selftest/tcp-ao: Work on namespace-ified sysctl_optmem_max 



Since commit f5769fae ("net: Namespace-ify sysctl_optmem_max")
optmem_max is per-netns, so need of switching to root namespace.
It seems trivial to keep the old logic working, so going to keep it for
a while (at least, until kernel with netns-optmem_max will be release).

Currently, there is a test that checks that optmem_max limit applies to
TCP-AO keys and a little benchmark that measures linked-list TCP-AO keys
scaling, those are fixed by this.

Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDmitry Safonov <dima@arista.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 72cd9f8d

tools/testing/selftests/net/tcp_ao/lib/setup.c

+27 −8
Original line number Diff line number Diff line
@@ -277,21 +277,37 @@ void __test_init(unsigned int ntests, int family, unsigned int prefix, 


/* /proc/sys/net/core/optmem_max artifically limits the amount of memory

 * that can be allocated with sock_kmalloc() on each socket in the system.

 * It is not virtualized, so it has to written outside test namespaces.

 * To be nice a test will revert optmem back to the old value.

 * It is not virtualized in v6.7, so it has to written outside test

 * namespaces. To be nice a test will revert optmem back to the old value.

 * Keeping it simple without any file lock, which means the tests that

 * need to set/increase optmem value shouldn't run in parallel.

 * Also, not re-entrant.

 * Since commit f5769faeec36 ("net: Namespace-ify sysctl_optmem_max")

 * it is per-namespace, keeping logic for non-virtualized optmem_max

 * for v6.7, which supports TCP-AO.

 */

static const char *optmem_file = "/proc/sys/net/core/optmem_max";

static size_t saved_optmem;

static int optmem_ns = -1;



static bool is_optmem_namespaced(void)

{

	if (optmem_ns == -1) {

		int old_ns = switch_save_ns(nsfd_child);



		optmem_ns = !access(optmem_file, F_OK);

		switch_ns(old_ns);

	}

	return !!optmem_ns;

}



size_t test_get_optmem(void)

{

	int old_ns = 0;

	FILE *foptmem;

	int old_ns;

	size_t ret;



	if (!is_optmem_namespaced())

		old_ns = switch_save_ns(nsfd_outside);

	foptmem = fopen(optmem_file, "r");

	if (!foptmem)
@@ -300,18 +316,20 @@ size_t test_get_optmem(void) 
	if (fscanf(foptmem, "%zu", &ret) != 1)

		test_error("can't read from %s", optmem_file);

	fclose(foptmem);

	if (!is_optmem_namespaced())

		switch_ns(old_ns);

	return ret;

}



static void __test_set_optmem(size_t new, size_t *old)

{

	int old_ns = 0;

	FILE *foptmem;

	int old_ns;



	if (old != NULL)

		*old = test_get_optmem();



	if (!is_optmem_namespaced())

		old_ns = switch_save_ns(nsfd_outside);

	foptmem = fopen(optmem_file, "w");

	if (!foptmem)
@@ -320,6 +338,7 @@ static void __test_set_optmem(size_t new, size_t *old) 
	if (fprintf(foptmem, "%zu", new) <= 0)

		test_error("can't write %zu to %s", new, optmem_file);

	fclose(foptmem);

	if (!is_optmem_namespaced())

		switch_ns(old_ns);

}