On Wed, 31 December 2003 06:13:16 -0500, Lennert Buytenhek wrote:
>
> When generating packets with pktgen with count=10, I get a divide-by-zero
> oops in inject().
>
> Line 273 in net/core/pktgen.c seems unsafe:
> __u64 pps = (__u32)(info->sofar * 1000) / ((__u32)(total) / 1000);
>
> What if total < 1000 ?
Since noone else seemed to care, try this patch. Against -test11,
yeah, I'm lazy again.
J?rn
--
Time? What's that? Time is only worth what you do with it.
-- Theo de Raadt
--- old/net/core/pktgen.c 2003-11-26 21:44:47.000000000 +0100
+++ new/net/core/pktgen.c 2004-01-18 16:27:10.000000000 +0100
@@ -720,7 +720,9 @@
{
char *p = info->result;
- __u64 pps = (__u32)(info->sofar * 1000) / ((__u32)(total) / 1000);
+ __u32 safe_total = (__u32)(total) / 1000;
+ safe_total += 1 - (!!safe_total); /* avoid divide-by-zero */
+ __u64 pps = (__u32)(info->sofar * 1000) / safe_total;
__u64 bps = pps * 8 * (info->pkt_size + 4); /* take 32bit ethernet CRC into account */
p += sprintf(p, "OK: %llu(c%llu+d%llu) usec, %llu (%dbyte,%dfrags) %llupps %lluMb/sec (%llubps) errors: %llu",
(unsigned long long) total,
Hi, Jörn Engel wrote:
> + safe_total += 1 - (!!safe_total); /* avoid divide-by-zero */
That's a (binary ;-) order of magnitude more complicated than necessary:
>> + safe_total += !safe_total; /* avoid divide-by-zero */
--
Matthias Urlichs | {M:U} IT Design @ m-u-it.de | [email protected]
Disclaimer: The quote was selected randomly. Really. | http://smurf.noris.de
- -
To believe that the nonexistence of God is a fact on the level of water
not running uphill, or the moon not having an atmosphere, requires far
more faith than I could ever muster. -- Arthur D. Hlavaty
Hello!
J?rn Engel writes:
> On Wed, 31 December 2003 06:13:16 -0500, Lennert Buytenhek wrote:
> >
> > When generating packets with pktgen with count=10, I get a divide-by-zero
> > oops in inject().
> >
> > Line 273 in net/core/pktgen.c seems unsafe:
> > __u64 pps = (__u32)(info->sofar * 1000) / ((__u32)(total) / 1000);
> >
> > What if total < 1000 ?
>
> Since noone else seemed to care, try this patch. Against -test11,
> yeah, I'm lazy again.
Sorry I missed Lennerts original posting...
I suggest the patch below to get integer precision at very short time
intervals too.
--- linux-2.6.1/net/core/pktgen.c.orig Sun Jan 18 21:56:56 2004
+++ linux-2.6.1/net/core/pktgen.c Sun Jan 18 23:15:03 2004
@@ -88,7 +88,7 @@
#define cycles() ((u32)get_cycles())
-#define VERSION "pktgen version 1.3"
+#define VERSION "pktgen version 1.31"
static char version[] __initdata =
"pktgen.c: v1.3: Packet Generator for packet performance testing.\n";
@@ -720,8 +720,18 @@
{
char *p = info->result;
- __u64 pps = (__u32)(info->sofar * 1000) / ((__u32)(total) / 1000);
- __u64 bps = pps * 8 * (info->pkt_size + 4); /* take 32bit ethernet CRC into account */
+ __u64 bps, pps = 0;
+
+ if (total > 1000)
+ pps = (__u32)(info->sofar * 1000) / ((__u32)(total) / 1000);
+ else if(total > 100)
+ pps = (__u32)(info->sofar * 10000) / ((__u32)(total) / 100);
+ else if(total > 10)
+ pps = (__u32)(info->sofar * 100000) / ((__u32)(total) / 10);
+ else if(total > 1)
+ pps = (__u32)(info->sofar * 1000000) / (__u32)total;
+
+ bps = pps * 8 * (info->pkt_size + 4); /* take 32bit ethernet CRC into account */
p += sprintf(p, "OK: %llu(c%llu+d%llu) usec, %llu (%dbyte,%dfrags) %llupps %lluMb/sec (%llubps) errors: %llu",
(unsigned long long) total,
(unsigned long long) (total - idle),
Cheers.
--ro
On Mon, 19 Jan 2004 00:15:41 +0100
Robert Olsson <[email protected]> wrote:
> I suggest the patch below to get integer precision at very short time
> intervals too.
Applied, thanks Robert.