[igt-dev] [PATCH i-g-t 1/6] runner: Use a bigger buffer for receiving test outputs

[Kamil Konieczny]

Hi Petri,

On 2022-11-07 at 14:01:46 +0200, Petri Latvala wrote:
> 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>
> Cc: Arkadiusz Hiler <arek at hiler.eu>
> Cc: Kamil Konieczny <kamil.konieczny at linux.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 */

imho it is better to use define and also write this as 256*1024
and put it in header.

If you increase this size maybe you can drop splitting ?

Kamil

> +	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
>