Re: [igt-dev] [Intel-gfx] [PATCH i-g-t v3 07/17] lib/ktap: Drop checks for EINTR on read() failures

[Mauro Carvalho Chehab <mauro.chehab@linux.intel.com>]

On Mon, 18 Sep 2023 15:42:57 +0200
Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com> wrote:

> While reading KTAP data from /dev/kmsg we now ignore EINTR failures that
> may occur during read() and we continue reading the data.  No explanation
> has been provided on what that could be needed for.
> 
> Since we use default SIGINT signal handler, read() should never fail with
> errno set to EINTR on user interrupt, only the whole process should be
> terminated.  Drop checks for errno == EINTR as not applicable.

This explanation makes sense to me.

Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org>


> 
> v2: Drop handling of EINTR completely, update commit message and
>     descripion.
> 
> Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
> Cc: Mauro Carvalho Chehab <mauro.chehab@linux.intel.com>

> ---
>  lib/igt_ktap.c | 15 ---------------
>  1 file changed, 15 deletions(-)
> 
> diff --git a/lib/igt_ktap.c b/lib/igt_ktap.c
> index 84fb13218f..ce07f9aed7 100644
> --- a/lib/igt_ktap.c
> +++ b/lib/igt_ktap.c
> @@ -66,9 +66,6 @@ static int log_to_end(enum igt_log_level level, int fd,
>  				return -2;
>  			}
>  
> -			if (errno == EINTR)
> -				continue;
> -
>  			if (errno == EPIPE) {
>  				igt_warn("kmsg truncated: too many messages. You may want to increase log_buf_len in kmcdline\n");
>  				return -2;
> @@ -188,9 +185,6 @@ static int find_next_tap_subtest(int fd, char *record, char *test_name, bool is_
>  				return -2;
>  			}
>  
> -			if (errno == EINTR)
> -				continue;
> -
>  			if (errno == EPIPE) {
>  				igt_warn("kmsg truncated: too many messages. You may want to increase log_buf_len in kmcdline\n");
>  				return -2;
> @@ -232,9 +226,6 @@ static int find_next_tap_subtest(int fd, char *record, char *test_name, bool is_
>  				return -2;
>  			}
>  
> -			if (errno == EINTR)
> -				continue;
> -
>  			if (errno == EPIPE) {
>  				igt_warn("kmsg truncated: too many messages. You may want to increase log_buf_len in kmcdline\n");
>  				return -2;
> @@ -387,9 +378,6 @@ static int parse_tap_level(int fd, char *base_test_name, int test_count, bool *f
>  				return -1;
>  			}
>  
> -			if (errno == EINTR)
> -				continue;
> -
>  			if (errno == EAGAIN)
>  				/* No records available */
>  				continue;
> @@ -540,9 +528,6 @@ igt_ktap_parser_start:
>  			/* No records available */
>  			continue;
>  
> -		if (errno == EINTR)
> -			continue;
> -
>  		if (errno == EPIPE) {
>  			igt_warn("kmsg truncated: too many messages. You may want to increase log_buf_len in kmcdline\n");
>  			goto igt_ktap_parser_end;