[v5] testpmd: cleanup cleanly from signal

Message ID 20221109172927.71411-1-stephen@networkplumber.org (mailing list archive)
State Superseded, archived
Delegated to: Andrew Rybchenko
Headers
Series [v5] testpmd: cleanup cleanly from signal |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/github-robot: build success github build: passed
ci/Intel-compilation success Compilation OK
ci/intel-Testing success Testing PASS
ci/iol-mellanox-Performance success Performance Testing PASS
ci/iol-aarch64-unit-testing success Testing PASS
ci/iol-intel-Performance success Performance Testing PASS
ci/iol-intel-Functional success Functional Testing PASS
ci/iol-x86_64-compile-testing success Testing PASS
ci/iol-x86_64-unit-testing success Testing PASS
ci/iol-aarch64-compile-testing success Testing PASS

Commit Message

Stephen Hemminger Nov. 9, 2022, 5:29 p.m. UTC
  Do a clean shutdown of testpmd when a signal is received;
instead of having testpmd kill itself.
This fixes problem where a signal could be received
in the middle of a PMD and then the signal handler would call
PMD's close routine which could cause a deadlock.

Added benefit is it gets rid of Windows specific code.

Fixes: d9a191a00e81 ("app/testpmd: fix quitting in container")
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
v5 - fix build on Windows.
     Windows has select() function but the prototype is in winsock.h
     not sys/select.h

 app/test-pmd/testpmd.c | 63 +++++++++++++++++++++++-------------------
 1 file changed, 34 insertions(+), 29 deletions(-)
  

Comments

Andrew Rybchenko Nov. 10, 2022, 7:14 a.m. UTC | #1
On 11/9/22 20:29, Stephen Hemminger wrote:
> Do a clean shutdown of testpmd when a signal is received;
> instead of having testpmd kill itself.
> This fixes problem where a signal could be received
> in the middle of a PMD and then the signal handler would call
> PMD's close routine which could cause a deadlock.
> 
> Added benefit is it gets rid of Windows specific code.
> 
> Fixes: d9a191a00e81 ("app/testpmd: fix quitting in container")

Cc to stable?

> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

with one nit below:

Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>

[snip]

> @@ -4476,15 +4459,37 @@ main(int argc, char** argv)
>   				prev_time = cur_time;
>   				rte_delay_us_sleep(US_PER_S);
>   			}
> -		}
> +		} else {
> +			char c;
> +			fd_set fds;
>   
> -		printf("Press enter to exit\n");
> -		rc = read(0, &c, 1);
> -		pmd_test_exit();
> -		if (rc < 0)
> -			return 1;
> +			printf("Press enter to exit\n");
> +
> +			FD_ZERO(&fds);
> +			FD_SET(0, &fds);
> +
> +			if (select(1, &fds, NULL, NULL, NULL) <= 0) {
> +				fprintf(stderr, "Select failed: %s\n",
> +					strerror(errno));
> +			} else if (read(0, &c, 1) <= 0) {
> +				fprintf(stderr,
> +					"Read stdin failed: %s\n",
> +					strerror(errno));
> +			}
> +		}
> +		stop_packet_forwarding();

force_quit() calls stop_packet_forwarding() if test_done is 0.
So, there is no difference in test_done == 0 case.
If test_done is not zero, stop_packet_forwarding() just logs
"Packet forwarding not started" and does nothing. So, the
difference is only in error message. Is it intentional?

> +		force_quit();
>   	}
>   
> +#ifdef RTE_LIB_PDUMP
> +	/* uninitialize packet capture framework */
> +	rte_pdump_uninit();
> +#endif
> +#ifdef RTE_LIB_LATENCYSTATS
> +	if (latencystats_enabled != 0)
> +		rte_latencystats_uninit();
> +#endif
> +
>   	ret = rte_eal_cleanup();
>   	if (ret != 0)
>   		rte_exit(EXIT_FAILURE,
  
Stephen Hemminger Nov. 10, 2022, 4:13 p.m. UTC | #2
> > +		stop_packet_forwarding();  
> 
> force_quit() calls stop_packet_forwarding() if test_done is 0.
> So, there is no difference in test_done == 0 case.
> If test_done is not zero, stop_packet_forwarding() just logs
> "Packet forwarding not started" and does nothing. So, the
> difference is only in error message. Is it intentional?
> 
> > +		force_quit();
> >   	}

Will fix in new version, it was a logic error.
  

Patch

diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index cf5942d0c422..be8fa7f0a0b1 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -11,6 +11,7 @@ 
 #include <fcntl.h>
 #ifndef RTE_EXEC_ENV_WINDOWS
 #include <sys/mman.h>
+#include <sys/select.h>
 #endif
 #include <sys/types.h>
 #include <errno.h>
@@ -4251,26 +4252,11 @@  print_stats(void)
 static void
 signal_handler(int signum)
 {
-	if (signum == SIGINT || signum == SIGTERM) {
-		fprintf(stderr, "\nSignal %d received, preparing to exit...\n",
-			signum);
-#ifdef RTE_LIB_PDUMP
-		/* uninitialize packet capture framework */
-		rte_pdump_uninit();
-#endif
-#ifdef RTE_LIB_LATENCYSTATS
-		if (latencystats_enabled != 0)
-			rte_latencystats_uninit();
-#endif
-		force_quit();
-		/* Set flag to indicate the force termination. */
-		f_quit = 1;
-		/* exit with the expected status */
-#ifndef RTE_EXEC_ENV_WINDOWS
-		signal(signum, SIG_DFL);
-		kill(getpid(), signum);
-#endif
-	}
+	fprintf(stderr, "\nSignal %d received, preparing to exit...\n",
+		signum);
+
+	/* Set flag to indicate the force termination. */
+	f_quit = 1;
 }
 
 int
@@ -4449,9 +4435,6 @@  main(int argc, char** argv)
 	} else
 #endif
 	{
-		char c;
-		int rc;
-
 		f_quit = 0;
 
 		printf("No commandline core given, start packet forwarding\n");
@@ -4476,15 +4459,37 @@  main(int argc, char** argv)
 				prev_time = cur_time;
 				rte_delay_us_sleep(US_PER_S);
 			}
-		}
+		} else {
+			char c;
+			fd_set fds;
 
-		printf("Press enter to exit\n");
-		rc = read(0, &c, 1);
-		pmd_test_exit();
-		if (rc < 0)
-			return 1;
+			printf("Press enter to exit\n");
+
+			FD_ZERO(&fds);
+			FD_SET(0, &fds);
+
+			if (select(1, &fds, NULL, NULL, NULL) <= 0) {
+				fprintf(stderr, "Select failed: %s\n",
+					strerror(errno));
+			} else if (read(0, &c, 1) <= 0) {
+				fprintf(stderr,
+					"Read stdin failed: %s\n",
+					strerror(errno));
+			}
+		}
+		stop_packet_forwarding();
+		force_quit();
 	}
 
+#ifdef RTE_LIB_PDUMP
+	/* uninitialize packet capture framework */
+	rte_pdump_uninit();
+#endif
+#ifdef RTE_LIB_LATENCYSTATS
+	if (latencystats_enabled != 0)
+		rte_latencystats_uninit();
+#endif
+
 	ret = rte_eal_cleanup();
 	if (ret != 0)
 		rte_exit(EXIT_FAILURE,