From f66f88383848565f65db3029b4c4fbfc424906e1 Mon Sep 17 00:00:00 2001 From: Dave Barach Date: Thu, 23 Jan 2020 08:44:40 -0500 Subject: [PATCH] api: mark api_trace_command_fn thread-safe Binary API trace replay with multiple worker threads depends in many cases on worker thread graph replica maintenance. If we (implicitly) assert a worker thread barrier at the debug CLI level, all graph replica changes are deferred until the replay operation completes. If an interface is deleted, the wheels may fall off. Type: fix Ticket: VPP-1824 Signed-off-by: Dave Barach Change-Id: I9b07d43f8501caa5519e5ff9ae4c19dc2661cc84 --- src/vlibmemory/vlib_api_cli.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/src/vlibmemory/vlib_api_cli.c b/src/vlibmemory/vlib_api_cli.c index db4871179d6..c79ac2bc75a 100755 --- a/src/vlibmemory/vlib_api_cli.c +++ b/src/vlibmemory/vlib_api_cli.c @@ -671,6 +671,16 @@ vl_msg_api_process_file (vlib_main_t * vm, u8 * filename, am->replay_in_progress = 0; } +/** api_trace_command_fn - control the binary API trace / replay feature + + Note: this command MUST be marked thread-safe. Replay with + multiple worker threads depends in many cases on worker thread + graph replica maintenance. If we (implicitly) assert a worker + thread barrier at the debug CLI level, all graph replica changes + are deferred until the replay operation completes. If an interface + is deleted, the wheels fall off. + */ + static clib_error_t * api_trace_command_fn (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd) @@ -691,12 +701,16 @@ api_trace_command_fn (vlib_main_t * vm, { if (unformat (input, "nitems %d", &nitems)) ; + vlib_worker_thread_barrier_sync (vm); vl_msg_api_trace_configure (am, which, nitems); vl_msg_api_trace_onoff (am, which, 1 /* on */ ); + vlib_worker_thread_barrier_release (vm); } else if (unformat (input, "off")) { + vlib_worker_thread_barrier_sync (vm); vl_msg_api_trace_onoff (am, which, 0); + vlib_worker_thread_barrier_release (vm); } else if (unformat (input, "save %s", &filename)) { @@ -718,7 +732,9 @@ api_trace_command_fn (vlib_main_t * vm, vlib_cli_output (vm, "Couldn't create %s\n", chroot_filename); goto out; } + vlib_worker_thread_barrier_sync (vm); rv = vl_msg_api_trace_save (am, which, fp); + vlib_worker_thread_barrier_release (vm); fclose (fp); if (rv == -1) vlib_cli_output (vm, "API Trace data not present\n"); @@ -775,8 +791,10 @@ api_trace_command_fn (vlib_main_t * vm, } else if (unformat (input, "free")) { + vlib_worker_thread_barrier_sync (vm); vl_msg_api_trace_onoff (am, which, 0); vl_msg_api_trace_free (am, which); + vlib_worker_thread_barrier_release (vm); } else if (unformat (input, "post-mortem-on")) vl_msg_api_post_mortem_dump_enable_disable (1 /* enable */ ); @@ -801,8 +819,9 @@ VLIB_CLI_COMMAND (api_trace_command, static) = { .path = "api trace", .short_help = "api trace [on|off][first ][last ][status][free]" - "[post-mortem-on][dump|custom-dump|save|replay ]", + "[post-mortem-on][dump|custom-dump|save|replay ]", .function = api_trace_command_fn, + .is_mp_safe = 1, }; /* *INDENT-ON* */ -- 2.16.6