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authorTimo Teras <timo.teras@iki.fi>2011-06-20 07:38:13 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2011-06-20 07:38:13 (GMT)
commite12e0acb92329f95a77121f489b491d84b6a2c33 (patch)
tree60678cbeedfbe3b2df3dcbc36b3e921bb8a6cd64
parent416e978ce80997088d3f0f2dd532554863d95ab5 (diff)
downloadbusybox-e12e0acb92329f95a77121f489b491d84b6a2c33.tar.gz
busybox-e12e0acb92329f95a77121f489b491d84b6a2c33.tar.bz2
modprobe: use hash table. speeds up significantly if modprobe.dep is large
function old new delta helper_get_module 106 157 +51 config_file_action 413 431 +18 modprobe_main 690 706 +16 do_modprobe 580 588 +8 add_probe 81 83 +2 load_modules_dep 192 190 -2 get_or_add_modentry 10 - -10 ------------------------------------------------------------------------------ (add/remove: 0/1 grow/shrink: 5/1 up/down: 95/-12) Total: 83 bytes Signed-off-by: Timo Teras <timo.teras@iki.fi> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--modutils/modprobe.c43
1 files changed, 29 insertions, 14 deletions
diff --git a/modutils/modprobe.c b/modutils/modprobe.c
index 678f4be..c1a1828 100644
--- a/modutils/modprobe.c
+++ b/modutils/modprobe.c
@@ -157,20 +157,21 @@ struct module_entry { /* I'll call it ME. */
llist_t *deps; /* strings. modules we depend on */
};
+#define DB_HASH_SIZE 256
+
struct globals {
- llist_t *db; /* MEs of all modules ever seen (caching for speed) */
llist_t *probes; /* MEs of module(s) requested on cmdline */
char *cmdline_mopts; /* module options from cmdline */
int num_unresolved_deps;
/* bool. "Did we have 'symbol:FOO' requested on cmdline?" */
smallint need_symbols;
struct utsname uts;
+ llist_t *db[DB_HASH_SIZE]; /* MEs of all modules ever seen (caching for speed) */
} FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
-#define INIT_G() do { } while (0)
-struct BUG_G_too_big {
- char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
-};
+#define G (*ptr_to_globals)
+#define INIT_G() do { \
+ SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
+} while (0)
static int read_config(const char *path);
@@ -190,14 +191,26 @@ static char *gather_options_str(char *opts, const char *append)
return opts;
}
+/* These three functions called many times, optimizing for speed.
+ * Users reported minute-long delays when they runn iptables repeatedly
+ * (iptables use modprobe to install needed kernel modules).
+ */
static struct module_entry *helper_get_module(const char *module, int create)
{
char modname[MODULE_NAME_LEN];
struct module_entry *e;
llist_t *l;
+ unsigned i;
+ unsigned hash;
filename2modname(module, modname);
- for (l = G.db; l != NULL; l = l->link) {
+
+ hash = 0;
+ for (i = 0; modname[i]; i++)
+ hash = ((hash << 5) + hash) + modname[i];
+ hash %= DB_HASH_SIZE;
+
+ for (l = G.db[hash]; l; l = l->link) {
e = (struct module_entry *) l->data;
if (strcmp(e->modname, modname) == 0)
return e;
@@ -207,15 +220,15 @@ static struct module_entry *helper_get_module(const char *module, int create)
e = xzalloc(sizeof(*e));
e->modname = xstrdup(modname);
- llist_add_to(&G.db, e);
+ llist_add_to(&G.db[hash], e);
return e;
}
-static struct module_entry *get_or_add_modentry(const char *module)
+static ALWAYS_INLINE struct module_entry *get_or_add_modentry(const char *module)
{
return helper_get_module(module, 1);
}
-static struct module_entry *get_modentry(const char *module)
+static ALWAYS_INLINE struct module_entry *get_modentry(const char *module)
{
return helper_get_module(module, 0);
}
@@ -275,7 +288,7 @@ static int FAST_FUNC config_file_action(const char *filename,
continue;
filename2modname(tokens[1], wildcard);
- for (l = G.probes; l != NULL; l = l->link) {
+ for (l = G.probes; l; l = l->link) {
m = (struct module_entry *) l->data;
if (fnmatch(wildcard, m->modname, 0) != 0)
continue;
@@ -377,7 +390,6 @@ static char *parse_and_add_kcmdline_module_options(char *options, const char *mo
static int do_modprobe(struct module_entry *m)
{
int rc, first;
- llist_t *l;
if (!(m->flags & MODULE_FLAG_FOUND_IN_MODDEP)) {
if (!(option_mask32 & INSMOD_OPT_SILENT))
@@ -390,8 +402,11 @@ static int do_modprobe(struct module_entry *m)
if (!(option_mask32 & OPT_REMOVE))
m->deps = llist_rev(m->deps);
- for (l = m->deps; l != NULL; l = l->link)
- DBG("dep: %s", l->data);
+ if (0) {
+ llist_t *l;
+ for (l = m->deps; l; l = l->link)
+ DBG("dep: %s", l->data);
+ }
first = 1;
rc = 0;