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modprobe: use hash table. speeds up significantly if modprobe.dep is large

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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>
This commit is contained in:
Timo Teras 2011-06-20 09:38:13 +02:00 committed by Denys Vlasenko
parent 416e978ce8
commit e12e0acb92
1 changed files with 29 additions and 14 deletions
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43
modutils/modprobe.c
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@ -157,20 +157,21 @@ struct module_entry { /* I'll call it ME. */
llist_t *deps; /* strings. modules we depend on */ llist_t *deps; /* strings. modules we depend on */
}; };
#define DB_HASH_SIZE 256
struct globals { struct globals {
llist_t *db; /* MEs of all modules ever seen (caching for speed) */
llist_t *probes; /* MEs of module(s) requested on cmdline */ llist_t *probes; /* MEs of module(s) requested on cmdline */
char *cmdline_mopts; /* module options from cmdline */ char *cmdline_mopts; /* module options from cmdline */
int num_unresolved_deps; int num_unresolved_deps;
/* bool. "Did we have 'symbol:FOO' requested on cmdline?" */ /* bool. "Did we have 'symbol:FOO' requested on cmdline?" */
smallint need_symbols; smallint need_symbols;
struct utsname uts; struct utsname uts;
llist_t *db[DB_HASH_SIZE]; /* MEs of all modules ever seen (caching for speed) */
} FIX_ALIASING; } FIX_ALIASING;
#define G (*(struct globals*)&bb_common_bufsiz1) #define G (*ptr_to_globals)
#define INIT_G() do { } while (0) #define INIT_G() do { \
struct BUG_G_too_big { SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1]; } while (0)
};
static int read_config(const char *path); static int read_config(const char *path);
@ -190,14 +191,26 @@ static char *gather_options_str(char *opts, const char *append)
return opts; 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) static struct module_entry *helper_get_module(const char *module, int create)
{ {
char modname[MODULE_NAME_LEN]; char modname[MODULE_NAME_LEN];
struct module_entry *e; struct module_entry *e;
llist_t *l; llist_t *l;
unsigned i;
unsigned hash;
filename2modname(module, modname); 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; e = (struct module_entry *) l->data;
if (strcmp(e->modname, modname) == 0) if (strcmp(e->modname, modname) == 0)
return e; return e;
@ -207,15 +220,15 @@ static struct module_entry *helper_get_module(const char *module, int create)
e = xzalloc(sizeof(*e)); e = xzalloc(sizeof(*e));
e->modname = xstrdup(modname); e->modname = xstrdup(modname);
llist_add_to(&G.db, e); llist_add_to(&G.db[hash], e);
return 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); 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); return helper_get_module(module, 0);
} }
@ -275,7 +288,7 @@ static int FAST_FUNC config_file_action(const char *filename,
continue; continue;
filename2modname(tokens[1], wildcard); 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; m = (struct module_entry *) l->data;
if (fnmatch(wildcard, m->modname, 0) != 0) if (fnmatch(wildcard, m->modname, 0) != 0)
continue; 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) static int do_modprobe(struct module_entry *m)
{ {
int rc, first; int rc, first;
llist_t *l;
if (!(m->flags & MODULE_FLAG_FOUND_IN_MODDEP)) { if (!(m->flags & MODULE_FLAG_FOUND_IN_MODDEP)) {
if (!(option_mask32 & INSMOD_OPT_SILENT)) if (!(option_mask32 & INSMOD_OPT_SILENT))
@ -390,8 +402,11 @@ static int do_modprobe(struct module_entry *m)
if (!(option_mask32 & OPT_REMOVE)) if (!(option_mask32 & OPT_REMOVE))
m->deps = llist_rev(m->deps); m->deps = llist_rev(m->deps);
for (l = m->deps; l != NULL; l = l->link) if (0) {
DBG("dep: %s", l->data); llist_t *l;
for (l = m->deps; l; l = l->link)
DBG("dep: %s", l->data);
}
first = 1; first = 1;
rc = 0; rc = 0;