[PATCH 1/1] selftest/net: fix FILE_SIZE for 32 bit architecture.

[PATCH 1/1] selftest/net: fix FILE_SIZE for 32 bit architecture.

[Maninder Singh]

FILE_SZ is defined as (1UL << 35), it will overflow
for 32 bit system and logic will break.

Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Signed-off-by: Vaneet Narang <v.narang@samsung.com>
---
 tools/testing/selftests/net/tcp_mmap.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/net/tcp_mmap.c b/tools/testing/selftests/net/tcp_mmap.c
index e8c5dff..1d6ca12 100644
--- a/tools/testing/selftests/net/tcp_mmap.c
+++ b/tools/testing/selftests/net/tcp_mmap.c
@@ -85,7 +85,7 @@
 #define MSG_ZEROCOPY    0x4000000
 #endif
 
-#define FILE_SZ (1UL << 35)
+#define FILE_SZ (1ULL << 35)
 static int cfg_family = AF_INET6;
 static socklen_t cfg_alen = sizeof(struct sockaddr_in6);
 static int cfg_port = 8787;
@@ -134,7 +134,7 @@ void hash_zone(void *zone, unsigned int length)
 
 void *child_thread(void *arg)
 {
-	unsigned long total_mmap = 0, total = 0;
+	unsigned long long total_mmap = 0, total = 0;
 	struct tcp_zerocopy_receive zc;
 	unsigned long delta_usec;
 	int flags = MAP_SHARED;
@@ -316,7 +316,7 @@ int main(int argc, char *argv[])
 {
 	struct sockaddr_storage listenaddr, addr;
 	unsigned int max_pacing_rate = 0;
-	unsigned long total = 0;
+	unsigned long long total = 0;
 	char *host = NULL;
 	int fd, c, on = 1;
 	char *buffer;
@@ -431,7 +431,7 @@ int main(int argc, char *argv[])
 		zflg = 0;
 	}
 	while (total < FILE_SZ) {
-		long wr = FILE_SZ - total;
+		unsigned long long wr = FILE_SZ - total;
 
 		if (wr > chunk_size)
 			wr = chunk_size;
-- 
1.9.1

Re: [PATCH 1/1] selftest/net: fix FILE_SIZE for 32 bit architecture.

[Eric Dumazet]

On 08/02/2018 03:31 AM, Maninder Singh wrote:
> FILE_SZ is defined as (1UL << 35), it will overflow
> for 32 bit system and logic will break.
> 
> Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
> Signed-off-by: Vaneet Narang <v.narang@samsung.com>
> ---
>  tools/testing/selftests/net/tcp_mmap.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/testing/selftests/net/tcp_mmap.c b/tools/testing/selftests/net/tcp_mmap.c
> index e8c5dff..1d6ca12 100644
> --- a/tools/testing/selftests/net/tcp_mmap.c
> +++ b/tools/testing/selftests/net/tcp_mmap.c
> @@ -85,7 +85,7 @@
>  #define MSG_ZEROCOPY    0x4000000
>  #endif
>  
> -#define FILE_SZ (1UL << 35)
> +#define FILE_SZ (1ULL << 35)
>  static int cfg_family = AF_INET6;
>  static socklen_t cfg_alen = sizeof(struct sockaddr_in6);
>  static int cfg_port = 8787;
> @@ -134,7 +134,7 @@ void hash_zone(void *zone, unsigned int length)
>  
>  void *child_thread(void *arg)
>  {
> -	unsigned long total_mmap = 0, total = 0;
> +	unsigned long long total_mmap = 0, total = 0;
>  	struct tcp_zerocopy_receive zc;
>  	unsigned long delta_usec;
>  	int flags = MAP_SHARED;
> @@ -316,7 +316,7 @@ int main(int argc, char *argv[])
>  {
>  	struct sockaddr_storage listenaddr, addr;
>  	unsigned int max_pacing_rate = 0;
> -	unsigned long total = 0;
> +	unsigned long long total = 0;
>  	char *host = NULL;
>  	int fd, c, on = 1;
>  	char *buffer;
> @@ -431,7 +431,7 @@ int main(int argc, char *argv[])
>  		zflg = 0;
>  	}
>  	while (total < FILE_SZ) {
> -		long wr = FILE_SZ - total;
> +		unsigned long long wr = FILE_SZ - total;
>  
>  		if (wr > chunk_size)
>  			wr = chunk_size;
> 

What about using more conventional size_t instead of "unsigned long long" ?

RE: [PATCH 1/1] selftest/net: fix FILE_SIZE for 32 bit architecture.

[Maninder Singh]

Hi,

>On 08/02/2018 03:31 AM, Maninder Singh wrote:
>> FILE_SZ is defined as (1UL << 35), it will overflow
>> for 32 bit system and logic will break.
>> 
>> Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
>> Signed-off-by: Vaneet Narang <v.narang@samsung.com>
>> ---
>>  tools/testing/selftests/net/tcp_mmap.c | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>> 
>> diff --git a/tools/testing/selftests/net/tcp_mmap.c b/tools/testing/selftests/net/tcp_mmap.c
>> index e8c5dff..1d6ca12 100644
>> --- a/tools/testing/selftests/net/tcp_mmap.c
>> +++ b/tools/testing/selftests/net/tcp_mmap.c
>> @@ -85,7 +85,7 @@
>>  #define MSG_ZEROCOPY    0x4000000
>>  #endif
>>  
>> -#define FILE_SZ (1UL << 35)
>> +#define FILE_SZ (1ULL << 35)

...
...
>> @@ -431,7 +431,7 @@ int main(int argc, char *argv[])
>>                  zflg = 0;
>>          }
>>          while (total < FILE_SZ) {
>> -                long wr = FILE_SZ - total;
>> +                unsigned long long wr = FILE_SZ - total;
>>  
>>                  if (wr > chunk_size)
>>                          wr = chunk_size;
>> 
> 
>What about using more conventional size_t instead of "unsigned long long" ?

size_t is also equivalent to unsigned long and it will not hold value of (1 << 35) for 32 bit system.
So we can do two things.

(1) reduce FILE SIZE to (1 << 30), so that UL (size_t) can hold this value.
It will not show any perofrmance boost with ZEROCOPY. (checked on x86_64)

(2) use unsigned long long to work with both 32 and 64 bit system.
It will show performance boost with ZEROCOPY.(checked on x86_64)

What do you think?

Thanks and regards,
Maninder Singh

RE: [PATCH 1/1] selftest/net: fix FILE_SIZE for 32 bit architecture.

[David Laight]

From: Maninder Singh
> Sent: 03 August 2018 04:32
> >On 08/02/2018 03:31 AM, Maninder Singh wrote:
> >> FILE_SZ is defined as (1UL << 35), it will overflow
> >> for 32 bit system and logic will break.
> >>
> >> Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
> >> Signed-off-by: Vaneet Narang <v.narang@samsung.com>
> >> ---
> >>  tools/testing/selftests/net/tcp_mmap.c | 8 ++++----
> >>  1 file changed, 4 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/tools/testing/selftests/net/tcp_mmap.c b/tools/testing/selftests/net/tcp_mmap.c
> >> index e8c5dff..1d6ca12 100644
> >> --- a/tools/testing/selftests/net/tcp_mmap.c
> >> +++ b/tools/testing/selftests/net/tcp_mmap.c
> >> @@ -85,7 +85,7 @@
> >>  #define MSG_ZEROCOPY    0x4000000
> >>  #endif
> >>
> >> -#define FILE_SZ (1UL << 35)
> >> +#define FILE_SZ (1ULL << 35)
> 
> ...
> ...
> >> @@ -431,7 +431,7 @@ int main(int argc, char *argv[])
> >>                  zflg = 0;
> >>          }
> >>          while (total < FILE_SZ) {
> >> -                long wr = FILE_SZ - total;
> >> +                unsigned long long wr = FILE_SZ - total;
> >>
> >>                  if (wr > chunk_size)
> >>                          wr = chunk_size;
> >>
> >
> >What about using more conventional size_t instead of "unsigned long long" ?
> 
> size_t is also equivalent to unsigned long and it will not hold value of (1 << 35) for 32 bit system.
> So we can do two things.

Wouldn't the 'correct' type be off_t ?
In any case, IIRC, you have to do really horrid things in Linux to
access files larger than 2G on 32bit systems.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

RE: [PATCH 1/1] selftest/net: fix FILE_SIZE for 32 bit architecture.

[Maninder Singh]

>> >
>> >What about using more conventional size_t instead of "unsigned long long" ?
>> 
>> size_t is also equivalent to unsigned long and it will not hold value of (1 << 35) for 32 bit system.
>> So we can do two things.
> 
>Wouldn't the 'correct' type be off_t ?
>In any case, IIRC, you have to do really horrid things in Linux to
>access files larger than 2G on 32bit systems.
> 
>        David

Any inputs.

Thanks,
Maninder Singh