[PATCH i-g-t 1/2] runner: Use a bigger buffer for receiving test outputs

[Petri Latvala]

Stream-based receiving was able to use buffers of any size for read(),
but with datagrams we actually need to prepare for actual sizes. In
practice, some file dumps from tests come as single log packets of a
couple of kB.

Signed-off-by: Petri Latvala <petri.latvala at intel.com>
---
 runner/executor.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/runner/executor.c b/runner/executor.c
index a79a34e0..1fcc9afe 100644
--- a/runner/executor.c
+++ b/runner/executor.c
@@ -857,7 +857,8 @@ static int monitor_output(pid_t child,
 			  char **abortreason)
 {
 	fd_set set;
-	char buf[2048];
+	char *buf;
+	size_t bufsize;
 	char *outbuf = NULL;
 	size_t outbufsize = 0;
 	char current_subtest[256] = {};
@@ -910,6 +911,9 @@ static int monitor_output(pid_t child,
 		}
 	}
 
+	bufsize = 262144; /* 256 kiB */
+	buf = malloc(bufsize);
+
 	while (outfd >= 0 || errfd >= 0 || sigfd >= 0) {
 		const char *timeout_reason;
 		struct timeval tv = { .tv_sec = interval_length };
@@ -942,7 +946,7 @@ static int monitor_output(pid_t child,
 
 			time_last_activity = time_now;
 
-			s = read(outfd, buf, sizeof(buf));
+			s = read(outfd, buf, bufsize);
 			if (s <= 0) {
 				if (s < 0) {
 					errf("Error reading test's stdout: %m\n");
@@ -1037,7 +1041,7 @@ static int monitor_output(pid_t child,
 		if (errfd >= 0 && FD_ISSET(errfd, &set)) {
 			time_last_activity = time_now;
 
-			s = read(errfd, buf, sizeof(buf));
+			s = read(errfd, buf, bufsize);
 			if (s <= 0) {
 				if (s < 0) {
 					errf("Error reading test's stderr: %m\n");
@@ -1060,7 +1064,7 @@ static int monitor_output(pid_t child,
 
 			/* Fully drain everything */
 			while (true) {
-				s = recv(socketfd, buf, sizeof(buf), MSG_DONTWAIT);
+				s = recv(socketfd, buf, bufsize, MSG_DONTWAIT);
 
 				if (s < 0) {
 					if (errno == EAGAIN)
@@ -1394,6 +1398,7 @@ static int monitor_output(pid_t child,
 					fdatasync(outputs[_F_DMESG]);
 
 				close_watchdogs(settings);
+				free(buf);
 				free(outbuf);
 				close(outfd);
 				close(errfd);
@@ -1418,6 +1423,7 @@ static int monitor_output(pid_t child,
 	if (settings->sync)
 		fdatasync(outputs[_F_DMESG]);
 
+	free(buf);
 	free(outbuf);
 	close(outfd);
 	close(errfd);
-- 
2.30.2