From: Willem de Bruijn willemb@google.com
[ Upstream commit 16f6458f2478b55e2b628797bc81a4455045c74e ]
The msg_zerocopy test pins the sender and receiver threads to separate cores to reduce variance between runs.
But it hardcodes the cores and skips core 0, so it fails on machines with the selected cores offline, or simply fewer cores.
The test mainly gives code coverage in automated runs. The throughput of zerocopy ('-z') and non-zerocopy runs is logged for manual inspection.
Continue even when sched_setaffinity fails. Just log to warn anyone interpreting the data.
Fixes: 07b65c5b31ce ("test: add msg_zerocopy test") Reported-by: Colin Ian King colin.king@canonical.com Signed-off-by: Willem de Bruijn willemb@google.com Acked-by: Colin Ian King colin.king@canonical.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/testing/selftests/net/msg_zerocopy.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
--- a/tools/testing/selftests/net/msg_zerocopy.c +++ b/tools/testing/selftests/net/msg_zerocopy.c @@ -125,9 +125,8 @@ static int do_setcpu(int cpu) CPU_ZERO(&mask); CPU_SET(cpu, &mask); if (sched_setaffinity(0, sizeof(mask), &mask)) - error(1, 0, "setaffinity %d", cpu); - - if (cfg_verbose) + fprintf(stderr, "cpu: unable to pin, may increase variance.\n"); + else if (cfg_verbose) fprintf(stderr, "cpu: %u\n", cpu);
return 0;