diff options
author | Niklas Söderlund <niklas.soderlund@corigine.com> | 2022-03-15 13:29:48 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-08 15:40:21 +0300 |
commit | f9a666100955b3af5a083de2952bd1b2b4e3046a (patch) | |
tree | ae6344a6910906aac803bb810550b023467395ef /samples | |
parent | cd84ea3920aef936c559b63099ef0013ce6b2325 (diff) | |
download | linux-f9a666100955b3af5a083de2952bd1b2b4e3046a.tar.xz |
samples/bpf, xdpsock: Fix race when running for fix duration of time
[ Upstream commit 8fa42d78f6354bb96ad3a079dcbef528ca9fa9e0 ]
When running xdpsock for a fix duration of time before terminating
using --duration=<n>, there is a race condition that may cause xdpsock
to terminate immediately.
When running for a fixed duration of time the check to determine when to
terminate execution is in is_benchmark_done() and is being executed in
the context of the poller thread,
if (opt_duration > 0) {
unsigned long dt = (get_nsecs() - start_time);
if (dt >= opt_duration)
benchmark_done = true;
}
However start_time is only set after the poller thread have been
created. This leaves a small window when the poller thread is starting
and calls is_benchmark_done() for the first time that start_time is not
yet set. In that case start_time have its initial value of 0 and the
duration check fails as it do not correlate correctly for the
applications start time and immediately sets benchmark_done which in
turn terminates the xdpsock application.
Fix this by setting start_time before creating the poller thread.
Fixes: d3f11b018f6c ("samples/bpf: xdpsock: Add duration option to specify how long to run")
Signed-off-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220315102948.466436-1-niklas.soderlund@corigine.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'samples')
-rw-r--r-- | samples/bpf/xdpsock_user.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index 2e4508a6cb3a..cf5b0a895225 100644 --- a/samples/bpf/xdpsock_user.c +++ b/samples/bpf/xdpsock_user.c @@ -1520,14 +1520,15 @@ int main(int argc, char **argv) setlocale(LC_ALL, ""); + prev_time = get_nsecs(); + start_time = prev_time; + if (!opt_quiet) { ret = pthread_create(&pt, NULL, poller, NULL); if (ret) exit_with_error(ret); } - prev_time = get_nsecs(); - start_time = prev_time; if (opt_bench == BENCH_RXDROP) rx_drop_all(); |