diff mbox series

[v2,1/4] selftests: net: udpgso_bench_rx: Fix 'used uninitialized' compiler warning

Message ID 20230131130412.432549-1-andrei.gherzan@canonical.com
State Superseded
Headers show
Series [v2,1/4] selftests: net: udpgso_bench_rx: Fix 'used uninitialized' compiler warning | expand

Commit Message

Andrei Gherzan Jan. 31, 2023, 1:04 p.m. UTC
This change fixes the following compiler warning:

/usr/include/x86_64-linux-gnu/bits/error.h:40:5: warning: ‘gso_size’ may
be used uninitialized [-Wmaybe-uninitialized]
   40 |     __error_noreturn (__status, __errnum, __format,
   __va_arg_pack ());
         |
	 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	 udpgso_bench_rx.c: In function ‘main’:
	 udpgso_bench_rx.c:253:23: note: ‘gso_size’ was declared here
	   253 |         int ret, len, gso_size, budget = 256;

Signed-off-by: Andrei Gherzan <andrei.gherzan@canonical.com>
---
 tools/testing/selftests/net/udpgso_bench_rx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Willem de Bruijn Jan. 31, 2023, 1:39 p.m. UTC | #1
On Tue, Jan 31, 2023 at 8:06 AM Andrei Gherzan
<andrei.gherzan@canonical.com> wrote:
>
> The test tool can check that the zerocopy number of completions value is
> valid taking into consideration the number of datagram send calls. This can
> catch the system into a state where the datagrams are still in the system
> (for example in a qdisk, waiting for the network interface to return a
> completion notification, etc).
>
> This change adds a retry logic of computing the number of completions up to
> a configurable (via CLI) timeout (default: 2 seconds).
>
> Signed-off-by: Andrei Gherzan <andrei.gherzan@canonical.com>
> ---
>  tools/testing/selftests/net/udpgso_bench_tx.c | 38 +++++++++++++++----
>  1 file changed, 30 insertions(+), 8 deletions(-)
>
> diff --git a/tools/testing/selftests/net/udpgso_bench_tx.c b/tools/testing/selftests/net/udpgso_bench_tx.c
> index b47b5c32039f..5a29b5f24023 100644
> --- a/tools/testing/selftests/net/udpgso_bench_tx.c
> +++ b/tools/testing/selftests/net/udpgso_bench_tx.c
> @@ -62,6 +62,7 @@ static int    cfg_payload_len = (1472 * 42);
>  static int     cfg_port        = 8000;
>  static int     cfg_runtime_ms  = -1;
>  static bool    cfg_poll;
> +static int     cfg_poll_loop_timeout_ms = 2000;
>  static bool    cfg_segment;
>  static bool    cfg_sendmmsg;
>  static bool    cfg_tcp;
> @@ -235,16 +236,17 @@ static void flush_errqueue_recv(int fd)
>         }
>  }
>
> -static void flush_errqueue(int fd, const bool do_poll)
> +static void flush_errqueue(int fd, const bool do_poll,
> +               unsigned long poll_timeout, const bool poll_err)
>  {
>         if (do_poll) {
>                 struct pollfd fds = {0};
>                 int ret;
>
>                 fds.fd = fd;
> -               ret = poll(&fds, 1, 500);
> +               ret = poll(&fds, 1, poll_timeout);
>                 if (ret == 0) {
> -                       if (cfg_verbose)
> +                       if ((cfg_verbose) && (poll_err))
>                                 fprintf(stderr, "poll timeout\n");
>                 } else if (ret < 0) {
>                         error(1, errno, "poll");
> @@ -254,6 +256,22 @@ static void flush_errqueue(int fd, const bool do_poll)
>         flush_errqueue_recv(fd);
>  }
>
> +static void flush_errqueue_retry(int fd, const bool do_poll, unsigned long num_sends)
> +{
> +       unsigned long tnow, tstop;
> +       bool first_try = true;
> +
> +       tnow = gettimeofday_ms();
> +       tstop = tnow + cfg_poll_loop_timeout_ms;
> +       do {
> +               flush_errqueue(fd, do_poll, tstop - tnow, first_try);
> +               first_try = false;
> +               if (!do_poll)
> +                       usleep(1000);  // a throttling delay if polling is enabled

never reached
Andrei Gherzan Jan. 31, 2023, 2:40 p.m. UTC | #2
On 23/01/31 08:35AM, Willem de Bruijn wrote:
> On Tue, Jan 31, 2023 at 8:08 AM Andrei Gherzan
> <andrei.gherzan@canonical.com> wrote:
> >
> > Leaving unrecognized arguments buried in the output, can easily hide a
> > CLI/script typo. Avoid this by exiting when wrong arguments are provided to
> > the udpgso_bench test programs.
> >
> > Signed-off-by: Andrei Gherzan <andrei.gherzan@canonical.com>
> 
> I'm on the fence on this. Test binaries are not necessarily robust
> against bad input. If you insist.

I'll keep it in the set (for next v), but I don't mind if it doesn't end
up applied. It was just something I stumbled into.

> When sending patches to net, please always add a Fixes tag.

I'll keep that in mind.
Paolo Abeni Jan. 31, 2023, 2:51 p.m. UTC | #3
On Tue, 2023-01-31 at 13:04 +0000, Andrei Gherzan wrote:
> The test tool can check that the zerocopy number of completions value is
> valid taking into consideration the number of datagram send calls. This can
> catch the system into a state where the datagrams are still in the system
> (for example in a qdisk, waiting for the network interface to return a
> completion notification, etc).
> 
> This change adds a retry logic of computing the number of completions up to
> a configurable (via CLI) timeout (default: 2 seconds).
> 
> Signed-off-by: Andrei Gherzan <andrei.gherzan@canonical.com>
> ---
>  tools/testing/selftests/net/udpgso_bench_tx.c | 38 +++++++++++++++----
>  1 file changed, 30 insertions(+), 8 deletions(-)
> 
> diff --git a/tools/testing/selftests/net/udpgso_bench_tx.c b/tools/testing/selftests/net/udpgso_bench_tx.c
> index b47b5c32039f..5a29b5f24023 100644
> --- a/tools/testing/selftests/net/udpgso_bench_tx.c
> +++ b/tools/testing/selftests/net/udpgso_bench_tx.c
> @@ -62,6 +62,7 @@ static int	cfg_payload_len	= (1472 * 42);
>  static int	cfg_port	= 8000;
>  static int	cfg_runtime_ms	= -1;
>  static bool	cfg_poll;
> +static int	cfg_poll_loop_timeout_ms = 2000;
>  static bool	cfg_segment;
>  static bool	cfg_sendmmsg;
>  static bool	cfg_tcp;
> @@ -235,16 +236,17 @@ static void flush_errqueue_recv(int fd)
>  	}
>  }
>  
> -static void flush_errqueue(int fd, const bool do_poll)
> +static void flush_errqueue(int fd, const bool do_poll,
> +		unsigned long poll_timeout, const bool poll_err)
>  {
>  	if (do_poll) {
>  		struct pollfd fds = {0};
>  		int ret;
>  
>  		fds.fd = fd;
> -		ret = poll(&fds, 1, 500);
> +		ret = poll(&fds, 1, poll_timeout);
>  		if (ret == 0) {
> -			if (cfg_verbose)
> +			if ((cfg_verbose) && (poll_err))
>  				fprintf(stderr, "poll timeout\n");
>  		} else if (ret < 0) {
>  			error(1, errno, "poll");
> @@ -254,6 +256,22 @@ static void flush_errqueue(int fd, const bool do_poll)
>  	flush_errqueue_recv(fd);
>  }
>  
> +static void flush_errqueue_retry(int fd, const bool do_poll, unsigned long num_sends)
> +{
> +	unsigned long tnow, tstop;
> +	bool first_try = true;
> +
> +	tnow = gettimeofday_ms();
> +	tstop = tnow + cfg_poll_loop_timeout_ms;
> +	do {
> +		flush_errqueue(fd, do_poll, tstop - tnow, first_try);
> +		first_try = false;
> +		if (!do_poll)
> +			usleep(1000);  // a throttling delay if polling is enabled

Even if the kernel codying style is not very strictly enforced for
self-tests, please avoid c++ style comments.

More importantly, as Willem noded, this function is always called with
do_poll == true. You should drop such argument and the related branch
above.

> +		tnow = gettimeofday_ms();
> +	} while ((stat_zcopies != num_sends) && (tnow < tstop));
> +}
> +
>  static int send_tcp(int fd, char *data)
>  {
>  	int ret, done = 0, count = 0;
> @@ -413,8 +431,9 @@ static int send_udp_segment(int fd, char *data)
>  
>  static void usage(const char *filepath)
>  {
> -	error(1, 0, "Usage: %s [-46acmHPtTuvz] [-C cpu] [-D dst ip] [-l secs] [-M messagenr] [-p port] [-s sendsize] [-S gsosize]",
> -		    filepath);
> +	error(1, 0,
> +			"Usage: %s [-46acmHPtTuvz] [-C cpu] [-D dst ip] [-l secs] [-L secs] [-M messagenr] [-p port] [-s sendsize] [-S gsosize]",
> +			filepath);

Please avoid introducing unnecessary white-space changes (no reason to
move the usage text on a new line)

Cheers,

Paolo
Andrei Gherzan Jan. 31, 2023, 3:08 p.m. UTC | #4
On 23/01/31 03:51PM, Paolo Abeni wrote:
> On Tue, 2023-01-31 at 13:04 +0000, Andrei Gherzan wrote:
> > The test tool can check that the zerocopy number of completions value is
> > valid taking into consideration the number of datagram send calls. This can
> > catch the system into a state where the datagrams are still in the system
> > (for example in a qdisk, waiting for the network interface to return a
> > completion notification, etc).
> > 
> > This change adds a retry logic of computing the number of completions up to
> > a configurable (via CLI) timeout (default: 2 seconds).
> > 
> > Signed-off-by: Andrei Gherzan <andrei.gherzan@canonical.com>
> > ---
> >  tools/testing/selftests/net/udpgso_bench_tx.c | 38 +++++++++++++++----
> >  1 file changed, 30 insertions(+), 8 deletions(-)
> > 
> > diff --git a/tools/testing/selftests/net/udpgso_bench_tx.c b/tools/testing/selftests/net/udpgso_bench_tx.c
> > index b47b5c32039f..5a29b5f24023 100644
> > --- a/tools/testing/selftests/net/udpgso_bench_tx.c
> > +++ b/tools/testing/selftests/net/udpgso_bench_tx.c
> > @@ -62,6 +62,7 @@ static int	cfg_payload_len	= (1472 * 42);
> >  static int	cfg_port	= 8000;
> >  static int	cfg_runtime_ms	= -1;
> >  static bool	cfg_poll;
> > +static int	cfg_poll_loop_timeout_ms = 2000;
> >  static bool	cfg_segment;
> >  static bool	cfg_sendmmsg;
> >  static bool	cfg_tcp;
> > @@ -235,16 +236,17 @@ static void flush_errqueue_recv(int fd)
> >  	}
> >  }
> >  
> > -static void flush_errqueue(int fd, const bool do_poll)
> > +static void flush_errqueue(int fd, const bool do_poll,
> > +		unsigned long poll_timeout, const bool poll_err)
> >  {
> >  	if (do_poll) {
> >  		struct pollfd fds = {0};
> >  		int ret;
> >  
> >  		fds.fd = fd;
> > -		ret = poll(&fds, 1, 500);
> > +		ret = poll(&fds, 1, poll_timeout);
> >  		if (ret == 0) {
> > -			if (cfg_verbose)
> > +			if ((cfg_verbose) && (poll_err))
> >  				fprintf(stderr, "poll timeout\n");
> >  		} else if (ret < 0) {
> >  			error(1, errno, "poll");
> > @@ -254,6 +256,22 @@ static void flush_errqueue(int fd, const bool do_poll)
> >  	flush_errqueue_recv(fd);
> >  }
> >  
> > +static void flush_errqueue_retry(int fd, const bool do_poll, unsigned long num_sends)
> > +{
> > +	unsigned long tnow, tstop;
> > +	bool first_try = true;
> > +
> > +	tnow = gettimeofday_ms();
> > +	tstop = tnow + cfg_poll_loop_timeout_ms;
> > +	do {
> > +		flush_errqueue(fd, do_poll, tstop - tnow, first_try);
> > +		first_try = false;
> > +		if (!do_poll)
> > +			usleep(1000);  // a throttling delay if polling is enabled
> 
> Even if the kernel codying style is not very strictly enforced for
> self-tests, please avoid c++ style comments.
> 
> More importantly, as Willem noded, this function is always called with
> do_poll == true. You should drop such argument and the related branch
> above.

Agreed. I will drop.

> 
> > +		tnow = gettimeofday_ms();
> > +	} while ((stat_zcopies != num_sends) && (tnow < tstop));
> > +}
> > +
> >  static int send_tcp(int fd, char *data)
> >  {
> >  	int ret, done = 0, count = 0;
> > @@ -413,8 +431,9 @@ static int send_udp_segment(int fd, char *data)
> >  
> >  static void usage(const char *filepath)
> >  {
> > -	error(1, 0, "Usage: %s [-46acmHPtTuvz] [-C cpu] [-D dst ip] [-l secs] [-M messagenr] [-p port] [-s sendsize] [-S gsosize]",
> > -		    filepath);
> > +	error(1, 0,
> > +			"Usage: %s [-46acmHPtTuvz] [-C cpu] [-D dst ip] [-l secs] [-L secs] [-M messagenr] [-p port] [-s sendsize] [-S gsosize]",
> > +			filepath);
> 
> Please avoid introducing unnecessary white-space changes (no reason to
> move the usage text on a new line)

The only reason why I've done this was to make scripts/checkpatch.pl
happy:

WARNING: line length of 141 exceeds 100 columns
#83: FILE: tools/testing/selftests/net/udpgso_bench_tx.c:432:

I can drop and ignore the warning, or maybe it would have been better to
just mention this in git message. What do you prefer?
Andrei Gherzan Jan. 31, 2023, 4:31 p.m. UTC | #5
On 23/01/31 05:22PM, Paolo Abeni wrote:
> On Tue, 2023-01-31 at 15:08 +0000, Andrei Gherzan wrote:
> > On 23/01/31 03:51PM, Paolo Abeni wrote:
> > > On Tue, 2023-01-31 at 13:04 +0000, Andrei Gherzan wrote:
> > > > The test tool can check that the zerocopy number of completions value is
> > > > valid taking into consideration the number of datagram send calls. This can
> > > > catch the system into a state where the datagrams are still in the system
> > > > (for example in a qdisk, waiting for the network interface to return a
> > > > completion notification, etc).
> > > > 
> > > > This change adds a retry logic of computing the number of completions up to
> > > > a configurable (via CLI) timeout (default: 2 seconds).
> > > > 
> > > > Signed-off-by: Andrei Gherzan <andrei.gherzan@canonical.com>
> > > > ---
> > > >  tools/testing/selftests/net/udpgso_bench_tx.c | 38 +++++++++++++++----
> > > >  1 file changed, 30 insertions(+), 8 deletions(-)
> > > > 
> > > > diff --git a/tools/testing/selftests/net/udpgso_bench_tx.c b/tools/testing/selftests/net/udpgso_bench_tx.c
> > > > index b47b5c32039f..5a29b5f24023 100644
> > > > --- a/tools/testing/selftests/net/udpgso_bench_tx.c
> > > > +++ b/tools/testing/selftests/net/udpgso_bench_tx.c
> > > > @@ -62,6 +62,7 @@ static int	cfg_payload_len	= (1472 * 42);
> > > >  static int	cfg_port	= 8000;
> > > >  static int	cfg_runtime_ms	= -1;
> > > >  static bool	cfg_poll;
> > > > +static int	cfg_poll_loop_timeout_ms = 2000;
> > > >  static bool	cfg_segment;
> > > >  static bool	cfg_sendmmsg;
> > > >  static bool	cfg_tcp;
> > > > @@ -235,16 +236,17 @@ static void flush_errqueue_recv(int fd)
> > > >  	}
> > > >  }
> > > >  
> > > > -static void flush_errqueue(int fd, const bool do_poll)
> > > > +static void flush_errqueue(int fd, const bool do_poll,
> > > > +		unsigned long poll_timeout, const bool poll_err)
> > > >  {
> > > >  	if (do_poll) {
> > > >  		struct pollfd fds = {0};
> > > >  		int ret;
> > > >  
> > > >  		fds.fd = fd;
> > > > -		ret = poll(&fds, 1, 500);
> > > > +		ret = poll(&fds, 1, poll_timeout);
> > > >  		if (ret == 0) {
> > > > -			if (cfg_verbose)
> > > > +			if ((cfg_verbose) && (poll_err))
> > > >  				fprintf(stderr, "poll timeout\n");
> > > >  		} else if (ret < 0) {
> > > >  			error(1, errno, "poll");
> > > > @@ -254,6 +256,22 @@ static void flush_errqueue(int fd, const bool do_poll)
> > > >  	flush_errqueue_recv(fd);
> > > >  }
> > > >  
> > > > +static void flush_errqueue_retry(int fd, const bool do_poll, unsigned long num_sends)
> > > > +{
> > > > +	unsigned long tnow, tstop;
> > > > +	bool first_try = true;
> > > > +
> > > > +	tnow = gettimeofday_ms();
> > > > +	tstop = tnow + cfg_poll_loop_timeout_ms;
> > > > +	do {
> > > > +		flush_errqueue(fd, do_poll, tstop - tnow, first_try);
> > > > +		first_try = false;
> > > > +		if (!do_poll)
> > > > +			usleep(1000);  // a throttling delay if polling is enabled
> > > 
> > > Even if the kernel codying style is not very strictly enforced for
> > > self-tests, please avoid c++ style comments.
> > > 
> > > More importantly, as Willem noded, this function is always called with
> > > do_poll == true. You should drop such argument and the related branch
> > > above.
> > 
> > Agreed. I will drop.
> > 
> > > 
> > > > +		tnow = gettimeofday_ms();
> > > > +	} while ((stat_zcopies != num_sends) && (tnow < tstop));
> > > > +}
> > > > +
> > > >  static int send_tcp(int fd, char *data)
> > > >  {
> > > >  	int ret, done = 0, count = 0;
> > > > @@ -413,8 +431,9 @@ static int send_udp_segment(int fd, char *data)
> > > >  
> > > >  static void usage(const char *filepath)
> > > >  {
> > > > -	error(1, 0, "Usage: %s [-46acmHPtTuvz] [-C cpu] [-D dst ip] [-l secs] [-M messagenr] [-p port] [-s sendsize] [-S gsosize]",
> > > > -		    filepath);
> > > > +	error(1, 0,
> > > > +			"Usage: %s [-46acmHPtTuvz] [-C cpu] [-D dst ip] [-l secs] [-L secs] [-M messagenr] [-p port] [-s sendsize] [-S gsosize]",
> > > > +			filepath);
> > > 
> > > Please avoid introducing unnecessary white-space changes (no reason to
> > > move the usage text on a new line)
> > 
> > The only reason why I've done this was to make scripts/checkpatch.pl
> > happy:
> > 
> > WARNING: line length of 141 exceeds 100 columns
> > #83: FILE: tools/testing/selftests/net/udpgso_bench_tx.c:432:
> > 
> > I can drop and ignore the warning, or maybe it would have been better to
> > just mention this in git message. What do you prefer?
> 
> Long lines are allowed for (kernel) messages, to make them easily grep-
> able.
> 
> In this specific case you can either append the new text to the message
> without introducing that strange indentation or even better break the
> usage string alike:
> 
> 	"Usage: %s [-46acmHPtTuvz] [-C cpu] [-D dst ip] [-l secs] [-L secs]"
> 	" [-L secs] [-M messagenr] [-p port] [-s sendsize] [-S gsosize]"

Funny I went through this too but it also fails with:

WARNING: quoted string split across lines
#84: FILE: tools/testing/selftests/net/udpgso_bench_tx.c:433

This is how I usually do it but it seems like it's flagged too.
diff mbox series

Patch

diff --git a/tools/testing/selftests/net/udpgso_bench_rx.c b/tools/testing/selftests/net/udpgso_bench_rx.c
index 6a193425c367..d0895bd1933f 100644
--- a/tools/testing/selftests/net/udpgso_bench_rx.c
+++ b/tools/testing/selftests/net/udpgso_bench_rx.c
@@ -250,7 +250,7 @@  static int recv_msg(int fd, char *buf, int len, int *gso_size)
 static void do_flush_udp(int fd)
 {
 	static char rbuf[ETH_MAX_MTU];
-	int ret, len, gso_size, budget = 256;
+	int ret, len, gso_size = 0, budget = 256;
 
 	len = cfg_read_all ? sizeof(rbuf) : 0;
 	while (budget--) {