[igt-dev] [PATCH i-g-t v2] runner: Only show the kmsg overflow message once

[Petri Latvala]

On Wed, Mar 25, 2020 at 12:58:23PM +0000, Chris Wilson wrote:
> Instead of repeating every single time we overflow the read from kmsg,
> just once per test is enough warning.
> 
> v2: Just suppress the multiple s/underflow/overflow/ messages. Having a
> buffer smaller than a single kmsg packet is unlikely.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Petri Latvala <petri.latvala at intel.com>

Reviewed-by: Petri Latvala <petri.latvala at intel.com>


> ---
>  runner/executor.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/runner/executor.c b/runner/executor.c
> index a56cb5d66..d72a59376 100644
> --- a/runner/executor.c
> +++ b/runner/executor.c
> @@ -549,6 +549,7 @@ static int dump_dmesg(int kmsgfd, int outfd)
>  	int comparefd;
>  	unsigned flags;
>  	unsigned long long seq, cmpseq, usec;
> +	bool underflow_once = false;
>  	char cont;
>  	char buf[2048];
>  	ssize_t r;
> @@ -586,7 +587,10 @@ static int dump_dmesg(int kmsgfd, int outfd)
>  		r = read(kmsgfd, buf, sizeof(buf));
>  		if (r < 0) {
>  			if (errno == EPIPE) {
> -				errf("Warning: kernel log ringbuffer underflow, some records lost.\n");
> +				if (!underflow_once) {
> +					errf("Warning: kernel log ringbuffer underflow, some records lost.\n");
> +					underflow_once = true;
> +				}
>  				continue;
>  			} else if (errno == EINVAL) {
>  				errf("Warning: Buffer too small for kernel log record, record lost.\n");
> -- 
> 2.26.0
>