Robert Olsson wrote:
Randy.Dunlap writes:
> I don't see any simultaneous uses of the 2 buffers, so here's the
> union version of the patch (attached this time), although it only
> saves 4 bytes... so maybe the compiler had already realized that
> usage. Either one accomplishes a large stack reduction, but the
Hello!
Here is version with just one buffer.
Yep, even better: few changes + using sizeof.
How did you calculate the saving?
objdump the .o file before and after changes. Look at how much
temp space is allocated by "sub const,%esp" (on x86). E.g.:
9e8: 81 ec 24 01 00 00 sub $0x124,%esp
--ro
--- net/core/pktgen.c.050221 2005-02-21 14:02:40.000000000 +0100
+++ net/core/pktgen.c 2005-02-21 15:02:44.000000000 +0100
@@ -151,7 +151,7 @@
#include <asm/timex.h>
-#define VERSION "pktgen v2.57: Packet Generator for packet performance testing.\n"
+#define VERSION "pktgen v2.58: Packet Generator for packet performance testing.\n"
/* #define PG_DEBUG(a) a */
#define PG_DEBUG(a)
@@ -811,6 +811,7 @@
struct pktgen_dev *pkt_dev = (struct pktgen_dev*)(data);
char* pg_result = NULL;
int tmp = 0;
+ char buf[128];
pg_result = &(pkt_dev->result[0]);
@@ -1071,7 +1072,6 @@
return count;
}
if (!strcmp(name, "dst_min") || !strcmp(name, "dst")) {
- char buf[IP_NAME_SZ];
len = strn_len(&user_buffer[i], sizeof(pkt_dev->dst_min) - 1);
if (len < 0) { return len; }
@@ -1091,7 +1091,6 @@
return count;
}
if (!strcmp(name, "dst_max")) {
- char buf[IP_NAME_SZ];
len = strn_len(&user_buffer[i], sizeof(pkt_dev->dst_max) - 1);
if (len < 0) { return len; }
@@ -1112,9 +1111,7 @@
return count;
}
if (!strcmp(name, "dst6")) {
- char buf[128];
-
- len = strn_len(&user_buffer[i], 128 - 1);
+ len = strn_len(&user_buffer[i], sizeof(buf) - 1);
if (len < 0) return len;
pkt_dev->flags |= F_IPV6;
@@ -1136,9 +1133,7 @@
return count;
}
if (!strcmp(name, "dst6_min")) {
- char buf[128];
-
- len = strn_len(&user_buffer[i], 128 - 1);
+ len = strn_len(&user_buffer[i], sizeof(buf) - 1);
if (len < 0) return len;
pkt_dev->flags |= F_IPV6;
@@ -1159,9 +1154,7 @@
return count;
}
if (!strcmp(name, "dst6_max")) {
- char buf[128];
-
- len = strn_len(&user_buffer[i], 128 - 1);
+ len = strn_len(&user_buffer[i], sizeof(buf) - 1);
if (len < 0) return len;
pkt_dev->flags |= F_IPV6;
@@ -1181,9 +1174,7 @@
return count;
}
if (!strcmp(name, "src6")) {
- char buf[128];
-
- len = strn_len(&user_buffer[i], 128 - 1);
+ len = strn_len(&user_buffer[i], sizeof(buf) - 1);
if (len < 0) return len;
pkt_dev->flags |= F_IPV6;
@@ -1205,7 +1196,6 @@
return count;
}
if (!strcmp(name, "src_min")) {
- char buf[IP_NAME_SZ];
len = strn_len(&user_buffer[i], sizeof(pkt_dev->src_min) - 1);
if (len < 0) { return len; }
if (copy_from_user(buf, &user_buffer[i], len))
@@ -1224,7 +1214,6 @@
return count;
}
if (!strcmp(name, "src_max")) {
- char buf[IP_NAME_SZ];
len = strn_len(&user_buffer[i], sizeof(pkt_dev->src_max) - 1);
if (len < 0) { return len; }
if (copy_from_user(buf, &user_buffer[i], len))
--
~Randy
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