[PATCH] net/ipv4/netfilter/ip_tables.c: remove some inlines

From: Denys Vlasenko
Date: Sun Dec 16 2007 - 15:48:28 EST


Hi Patrick, Harald,

I was working on unrelated problem and noticed that ip_tables.c
seem to abuse inline. I prepared a patch which removes inlines
except those which are used by packet matching code
(and thus are really performance-critical).
I added comments explaining that remaining inlines are
performance critical.

Result as reported by size:

text data bss dec hex filename
- 6451 380 88 6919 1b07 ip_tables.o
+ 6339 348 72 6759 1a67 ip_tables.o

Please take this patch into netfilter queue.

Signed-off-by: Denys Vlasenko <vda.linux@xxxxxxxxxxxxxx>
--
vda
diff -urpN linux-2.6.org/net/ipv4/netfilter/ip_tables.c linux-2.6.ipt/net/ipv4/netfilter/ip_tables.c
--- linux-2.6.org/net/ipv4/netfilter/ip_tables.c 2007-12-14 10:46:37.000000000 -0800
+++ linux-2.6.ipt/net/ipv4/netfilter/ip_tables.c 2007-12-16 12:37:46.000000000 -0800
@@ -74,6 +74,7 @@ do { \
Hence the start of any table is given by get_table() below. */

/* Returns whether matches rule or not. */
+/* Performance critical - called for every packet */
static inline int
ip_packet_match(const struct iphdr *ip,
const char *indev,
@@ -152,7 +153,7 @@ ip_packet_match(const struct iphdr *ip,
return 1;
}

-static inline bool
+static bool
ip_checkentry(const struct ipt_ip *ip)
{
if (ip->flags & ~IPT_F_MASK) {
@@ -182,6 +183,7 @@ ipt_error(struct sk_buff *skb,
return NF_DROP;
}

+/* Performance critical - called for every packet */
static inline
bool do_match(struct ipt_entry_match *m,
const struct sk_buff *skb,
@@ -198,6 +200,7 @@ bool do_match(struct ipt_entry_match *m,
return false;
}

+/* Performance critical */
static inline struct ipt_entry *
get_entry(void *base, unsigned int offset)
{
@@ -205,6 +208,7 @@ get_entry(void *base, unsigned int offse
}

/* All zeroes == unconditional rule. */
+/* Mildly perf critical (only if packet tracing is on) */
static inline int
unconditional(const struct ipt_ip *ip)
{
@@ -219,7 +223,7 @@ unconditional(const struct ipt_ip *ip)

#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
-static const char *hooknames[] = {
+static const char *const hooknames[] = {
[NF_IP_PRE_ROUTING] = "PREROUTING",
[NF_IP_LOCAL_IN] = "INPUT",
[NF_IP_FORWARD] = "FORWARD",
@@ -233,7 +237,7 @@ enum nf_ip_trace_comments {
NF_IP_TRACE_COMMENT_POLICY,
};

-static const char *comments[] = {
+static const char *const comments[] = {
[NF_IP_TRACE_COMMENT_RULE] = "rule",
[NF_IP_TRACE_COMMENT_RETURN] = "return",
[NF_IP_TRACE_COMMENT_POLICY] = "policy",
@@ -249,6 +253,7 @@ static struct nf_loginfo trace_loginfo =
},
};

+/* Mildly perf critical (only if packet tracing is on) */
static inline int
get_chainname_rulenum(struct ipt_entry *s, struct ipt_entry *e,
char *hookname, char **chainname,
@@ -567,7 +572,7 @@ mark_source_chains(struct xt_table_info
return 1;
}

-static inline int
+static int
cleanup_match(struct ipt_entry_match *m, unsigned int *i)
{
if (i && (*i)-- == 0)
@@ -579,7 +584,7 @@ cleanup_match(struct ipt_entry_match *m,
return 0;
}

-static inline int
+static int
check_entry(struct ipt_entry *e, const char *name)
{
struct ipt_entry_target *t;
@@ -599,7 +604,7 @@ check_entry(struct ipt_entry *e, const c
return 0;
}

-static inline int check_match(struct ipt_entry_match *m, const char *name,
+static int check_match(struct ipt_entry_match *m, const char *name,
const struct ipt_ip *ip, unsigned int hookmask,
unsigned int *i)
{
@@ -622,7 +627,7 @@ static inline int check_match(struct ipt
return ret;
}

-static inline int
+static int
find_check_match(struct ipt_entry_match *m,
const char *name,
const struct ipt_ip *ip,
@@ -651,7 +656,7 @@ err:
return ret;
}

-static inline int check_target(struct ipt_entry *e, const char *name)
+static int check_target(struct ipt_entry *e, const char *name)
{
struct ipt_entry_target *t;
struct xt_target *target;
@@ -672,7 +677,7 @@ static inline int check_target(struct ip
return ret;
}

-static inline int
+static int
find_check_entry(struct ipt_entry *e, const char *name, unsigned int size,
unsigned int *i)
{
@@ -716,7 +721,7 @@ find_check_entry(struct ipt_entry *e, co
return ret;
}

-static inline int
+static int
check_entry_size_and_hooks(struct ipt_entry *e,
struct xt_table_info *newinfo,
unsigned char *base,
@@ -759,7 +764,7 @@ check_entry_size_and_hooks(struct ipt_en
return 0;
}

-static inline int
+static int
cleanup_entry(struct ipt_entry *e, unsigned int *i)
{
struct ipt_entry_target *t;
@@ -1293,7 +1298,7 @@ __do_replace(const char *name, unsigned
get_counters(oldinfo, counters);
/* Decrease module usage counts and free resource */
loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
- IPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,NULL);
+ IPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry, NULL);
xt_free_table_info(oldinfo);
if (copy_to_user(counters_ptr, counters,
sizeof(struct xt_counters) * num_counters) != 0)
@@ -1361,7 +1366,7 @@ do_replace(void __user *user, unsigned i
return 0;

free_newinfo_untrans:
- IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry,NULL);
+ IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
free_newinfo:
xt_free_table_info(newinfo);
return ret;
@@ -1369,7 +1374,7 @@ do_replace(void __user *user, unsigned i

/* We're lazy, and add to the first CPU; overflow works its fey magic
* and everything is OK. */
-static inline int
+static int
add_counter_to_entry(struct ipt_entry *e,
const struct xt_counters addme[],
unsigned int *i)
@@ -1527,7 +1532,7 @@ out:
return ret;
}

-static inline int
+static int
compat_find_calc_match(struct ipt_entry_match *m,
const char *name,
const struct ipt_ip *ip,
@@ -1551,7 +1556,7 @@ compat_find_calc_match(struct ipt_entry_
return 0;
}

-static inline int
+static int
compat_release_match(struct ipt_entry_match *m, unsigned int *i)
{
if (i && (*i)-- == 0)
@@ -1561,7 +1566,7 @@ compat_release_match(struct ipt_entry_ma
return 0;
}

-static inline int
+static int
compat_release_entry(struct ipt_entry *e, unsigned int *i)
{
struct ipt_entry_target *t;
@@ -1576,7 +1581,7 @@ compat_release_entry(struct ipt_entry *e
return 0;
}

-static inline int
+static int
check_compat_entry_size_and_hooks(struct ipt_entry *e,
struct xt_table_info *newinfo,
unsigned int *size,
@@ -1702,7 +1707,7 @@ static int compat_copy_entry_from_user(s
return ret;
}

-static inline int compat_check_entry(struct ipt_entry *e, const char *name,
+static int compat_check_entry(struct ipt_entry *e, const char *name,
unsigned int *i)
{
int j, ret;
@@ -1895,7 +1900,7 @@ compat_do_replace(void __user *user, uns
return 0;

free_newinfo_untrans:
- IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry,NULL);
+ IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
free_newinfo:
xt_free_table_info(newinfo);
return ret;