Re: [PATCH 1/2] selftests/watchdog: limit ping loop and allow configuring the number of pings

[Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>]

On 7/3/24 08:48, Laura Nao wrote:
> On 6/27/24 20:48, Shuah Khan wrote:
> > On 5/6/24 05:13, Laura Nao wrote:
> > > In order to run the watchdog selftest with the kselftest runner, the
> > > loop responsible for pinging the watchdog should be finite. This
> > > change limits the loop to 5 iterations by default and introduces a new
> > > '-c' option to adjust the number of pings as needed.
> >
> > This patch makes the test run finite in all cases changing the bevavior
> > to run it forever?
>
> Correct.
>
> > > Signed-off-by: Laura Nao <laura.nao@xxxxxxxxxxxxx>
> > > ---
> > >    tools/testing/selftests/watchdog/watchdog-test.c | 16 ++++++++++++++--
> > >    1 file changed, 14 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/tools/testing/selftests/watchdog/watchdog-test.c
> > > b/tools/testing/selftests/watchdog/watchdog-test.c
> > > index bc71cbca0dde..786cc5a26206 100644
> > > --- a/tools/testing/selftests/watchdog/watchdog-test.c
> > > +++ b/tools/testing/selftests/watchdog/watchdog-test.c
> > > @@ -24,16 +24,18 @@
> > >    #include <linux/watchdog.h>
> > >    #define DEFAULT_PING_RATE    1
> > > +#define DEFAULT_PING_COUNT    5
> > >    int fd;
> > >    const char v = 'V';
> > > -static const char sopts[] = "bdehp:st:Tn:NLf:i";
> > > +static const char sopts[] = "bdehp:c:st:Tn:NLf:i";
> > >    static const struct option lopts[] = {
> > >        {"bootstatus",          no_argument, NULL, 'b'},
> > >        {"disable",             no_argument, NULL, 'd'},
> > >        {"enable",              no_argument, NULL, 'e'},
> > >        {"help",                no_argument, NULL, 'h'},
> > >        {"pingrate",      required_argument, NULL, 'p'},
> > > +    {"pingcount",     required_argument, NULL, 'c'},
> > >        {"status",              no_argument, NULL, 's'},
> > >        {"timeout",       required_argument, NULL, 't'},
> > >        {"gettimeout",          no_argument, NULL, 'T'},
> > > @@ -90,6 +92,8 @@ static void usage(char *progname)
> > >        printf(" -h, --help\t\tPrint the help message\n");
> > >        printf(" -p, --pingrate=P\tSet ping rate to P seconds (default
> > > %d)\n",
> > >               DEFAULT_PING_RATE);
> > > +    printf(" -c, --pingcount=C\tSet number of pings to C (default
> > > %d)\n",
> > > +           DEFAULT_PING_COUNT);
> > >        printf(" -t, --timeout=T\tSet timeout to T seconds\n");
> > >        printf(" -T, --gettimeout\tGet the timeout\n");
> > >        printf(" -n, --pretimeout=T\tSet the pretimeout to T seconds\n");
> > > @@ -172,6 +176,7 @@ int main(int argc, char *argv[])
> > >    {
> > >        int flags;
> > >        unsigned int ping_rate = DEFAULT_PING_RATE;
> > > +    unsigned int ping_count = DEFAULT_PING_COUNT;
> > >        int ret;
> > >        int c;
> > >        int oneshot = 0;
> > > @@ -248,6 +253,12 @@ int main(int argc, char *argv[])
> > >                    ping_rate = DEFAULT_PING_RATE;
> > >                printf("Watchdog ping rate set to %u seconds.\n",
> > > ping_rate);
> > >                break;
> > > +        case 'c':
> > > +            ping_count = strtoul(optarg, NULL, 0);
> > > +            if (!ping_count)
> > > +                ping_count = DEFAULT_PING_COUNT;
> > > +            printf("Number of pings set to %u.\n", ping_count);
> > > +            break;
> > >            case 's':
> > >                flags = 0;
> > >                oneshot = 1;
> > > @@ -336,9 +347,10 @@ int main(int argc, char *argv[])
> > >        signal(SIGINT, term);
> > > -    while (1) {
> > > +    while (ping_count > 0) {
> > >            keep_alive();
> > >            sleep(ping_rate);
> > > +        ping_count--;
> >
> > So this test no longer runs forever?
>
> That's correct, with this patch applied the test no longer runs forever.
> I understand you prefer the current behavior - how about keeping the
> keep_alive() loop infinite by default and only making it finite when the
> -c argument is passed? Would that be reasonable?

Yes. I am open to taking the patch if the default behavior doesn't change.

thanks,
-- Shuah