Re: [LTP] [PATCH 2/2] syscalls/msgstress01: Fix timeouts

[Petr Vorel <pvorel@suse.cz>]

Hi Cyril,

> Make the test exit if runtime has been exhausted before we finished the
> requested amount of iterations.

> For that to happen we let the main test process to loop while checking
> the runtime and set the stop flag if runtime was exhausted. We also need
> to separte the stop and fail flag and add counter for finished children.
nit: s/separte/separate/

...
>  static void remove_queues(void)
> @@ -196,12 +210,37 @@ static void run(void)

>  		if (*stop)
>  			break;
> +
> +		if (!tst_remaining_runtime()) {
> +			tst_res(TWARN, "Out of runtime during forking...");

I tested the patchset on various VMs (various kernels), with both 1 or 2 CPU.
Indeed it fixes the problem. IMHO it can quite easily get KVM host overloaded
enough to get the TWARN out of runtime during forking, but we can't do anything
about it.

msgstress01.c:215: TWARN: Out of runtime during forking...
msgstress01.c:244: TPASS: Test passed. All messages have been received

> +			*stop = 1;
> +			break;
> +		}
> +	}
> +
> +	if (!(*stop))
> +		tst_res(TINFO, "All processes running.");
very nit: I'd remove dot at the end.

> +
> +	for (;;) {
> +		if (tst_atomic_load(finished) == 2 * num_messages)
> +			break;
> +
> +		if (*stop)
> +			break;
> +
> +		if (!tst_remaining_runtime()) {
> +			tst_res(TINFO, "Out of runtime, stopping processes...");
> +			*stop = 1;
> +			break;
> +		}
> +
> +		sleep(1);
>  	}

>  	tst_reap_children();
>  	remove_queues();

> -	if (!(*stop))
> +	if (!(*fail))
>  		tst_res(TPASS, "Test passed. All messages have been received");
>  }

> @@ -242,14 +281,16 @@ static void setup(void)
>  		MAP_SHARED | MAP_ANONYMOUS,
>  		-1, 0);

> -	stop = SAFE_MMAP(
> +	flags = SAFE_MMAP(
>  		NULL,
> -		sizeof(int),
> +		sizeof(int) * 3,
>  		PROT_READ | PROT_WRITE,
>  		MAP_SHARED | MAP_ANONYMOUS,
>  		-1, 0);

> -	reset_messages();
> +	stop = &flags[0];
> +	fail = &flags[1];
> +	finished = &flags[2];
>  }

>  static void cleanup(void)
> @@ -260,7 +301,7 @@ static void cleanup(void)
>  	remove_queues();

>  	SAFE_MUNMAP(ipc_data, sizeof(struct sysv_data) * num_messages);
> -	SAFE_MUNMAP((void *)stop, sizeof(int));
> +	SAFE_MUNMAP(flags, sizeof(int) * 3);
>  }

>  static struct tst_test test = {
> @@ -271,7 +312,7 @@ static struct tst_test test = {
>  	.max_runtime = 180,
>  	.options = (struct tst_option[]) {
>  		{"n:", &str_num_messages, "Number of messages to send (default: 1000)"},
> -		{"l:", &str_num_iterations, "Number iterations per message (default: 10000)"},
> +		{"l:", &str_num_iterations, "Number iterations per message (default: " TST_TO_STR(MAXNREPS) ")"},
>  		{},
very nit: too long line

Reviewed-by: Petr Vorel <pvorel@suse.cz>

Kind regards,
Petr

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