On Mon, 28 Sep 2020 16:49:45 -0700 Jacob Keller wrote:
> For some devices, updating the flash can take significant time during
> operations where no status can meaningfully be reported. This can be
> somewhat confusing to a user who sees devlink appear to hang on the
> terminal waiting for the device to update.
>
> Provide a ticking counter of the time elapsed since the previous status
> message in order to make it clear that the program is not simply stuck.
>
> Do not display this message unless a few seconds have passed since the
> last status update. Additionally, if the previous status notification
> included a timeout, display this as part of the message. If we do not
> receive an error or a new status without that time out, replace it with
> the text "timeout reached".
>
> Signed-off-by: Jacob Keller <[email protected]>
> ---
> Sending this as an RFC because I doubt this is the best implementation. For
> one, I get a weird display issue where the cursor doesn't always end up on
> the end of line in my shell.. The % display works properly, so I'm not sure
> what's wrong here.
>
> Second, even though select should be timing out every 1/10th of a second for
> screen updates, I don't seem to get that behavior in my test. It takes about
> 8 to 10 seconds for the first elapsed time message to be displayed, and it
> updates really slowly. Is select just not that precise? I even tried using a
> timeout of zero, but this means we refresh way too often and it looks bad. I
> am not sure what is wrong here...
Strange. Did you strace it? Perhaps it's some form of output buffering?
> diff --git a/devlink/devlink.c b/devlink/devlink.c
> index 0374175eda3d..7fb4b5ef1ebe 100644
> --- a/devlink/devlink.c
> +++ b/devlink/devlink.c
> @@ -33,6 +33,7 @@
> #include <sys/select.h>
> #include <sys/socket.h>
> #include <sys/types.h>
> +#include <sys/time.h>
> #include <rt_names.h>
>
> #include "version.h"
> @@ -3066,6 +3067,9 @@ static int cmd_dev_info(struct dl *dl)
>
> struct cmd_dev_flash_status_ctx {
> struct dl *dl;
> + struct timeval last_status_msg;
> + char timeout_msg[128];
Really you just need the length (as returned by snprintf), right?
> + uint64_t timeout;
> char *last_msg;
> char *last_component;
> uint8_t not_first:1,
> @@ -3083,6 +3087,14 @@ static int nullstrcmp(const char *str1, const char
> *str2)
> return str1 ? 1 : -1;
> }
>
> +static void cmd_dev_flash_clear_elapsed_time(struct cmd_dev_flash_status_ctx
> *ctx)
> +{
> + int i;
> +
> + for (i = 0; i < strlen(ctx->timeout_msg); i++)
> + pr_out_tty("\b");
I wonder if it's not easier to \r, I guess the existing code likes \b
so be it.
> +}
> +
> static int cmd_dev_flash_status_cb(const struct nlmsghdr *nlh, void *data)
> {
> struct cmd_dev_flash_status_ctx *ctx = data;
> +static void cmd_dev_flash_time_elapsed(struct cmd_dev_flash_status_ctx *ctx)
> +{
> + struct timeval now, res;
> +
> + gettimeofday(&now, NULL);
> + timersub(&now, &ctx->last_status_msg, &res);
> +
> + /* Don't start displaying a timeout message until we've elapsed a few
> + * seconds...
> + */
> + if (res.tv_sec > 3) {
> + uint elapsed_m, elapsed_s;
This may be the first uint use in iproute2..
> + /* clear the last elapsed time message, if we have one */
> + cmd_dev_flash_clear_elapsed_time(ctx);
> +
> + elapsed_m = res.tv_sec / 60;
> + elapsed_s = res.tv_sec % 60;
