Here is a diff that was originally hatched at c2k10 and finally implemented
at k2k11. This has been tested lightly so needs to be tested on all systems
with big and small programs.
On some machines this can shave 15% off of the startup time of large
applications with lots of dynamically loaded libraries.
Please test and let me know if there are any problems found.
Yes I am intentionally cross posting this to ports@ as large ports
are the most affected by this diff.
Maybe this will finally get ajacoutot@ off my back ;)
Index: dlfcn.c
===================================================================
RCS file: /cvs/src/libexec/ld.so/dlfcn.c,v
retrieving revision 1.82
diff -u -p -r1.82 dlfcn.c
--- dlfcn.c 1 Jul 2010 19:25:44 -0000 1.82
+++ dlfcn.c 17 Apr 2011 14:51:06 -0000
@@ -108,6 +108,7 @@ dlopen(const char *libname, int flags)
_dl_unload_shlib(object);
_dl_exit(0);
}
+ _dl_search_list_valid = 0;
err = _dl_rtld(object);
if (err != 0) {
_dl_real_close(object);
@@ -263,6 +264,7 @@ dlclose(void *handle)
retval = _dl_real_close(handle);
+ _dl_search_list_valid = 0;
if (_dl_debug_map->r_brk) {
_dl_debug_map->r_state = RT_CONSISTENT;
Index: loader.c
===================================================================
RCS file: /cvs/src/libexec/ld.so/loader.c,v
retrieving revision 1.122
diff -u -p -r1.122 loader.c
--- loader.c 6 Apr 2011 11:36:25 -0000 1.122
+++ loader.c 17 Apr 2011 14:51:06 -0000
@@ -516,6 +516,7 @@ _dl_boot(const char **argv, char **envp,
dyn_obj->status |= STAT_RELOC_DONE;
_dl_set_sod(dyn_obj->load_name, &dyn_obj->sod);
+ _dl_search_list_valid = 0;
/*
* Everything should be in place now for doing the relocation
* and binding. Call _dl_rtld to do the job. Fingers crossed.
Index: resolve.c
===================================================================
RCS file: /cvs/src/libexec/ld.so/resolve.c,v
retrieving revision 1.52
diff -u -p -r1.52 resolve.c
--- resolve.c 25 Oct 2010 20:34:44 -0000 1.52
+++ resolve.c 17 Apr 2011 14:52:26 -0000
@@ -213,6 +213,90 @@ _dl_cleanup_objects()
}
}
+struct dep_node_head _dlsym_search_list =
TAILQ_HEAD_INITIALIZER(_dlsym_search_list);
+int _dl_search_list_valid = 0;
+
+void
+_dl_rebuild_allobj_grouplist()
+{
+ struct dep_node *n, *m;
+ int global;
+ static int maxgrouplist = 0;
+ static int maxchildlist = 0;
+ int childlistlen = 0, grouplistlen = 0;
+
+ DL_DEB(("rebuil\n"));
+
+ /* get rid of old list */
+ while( (n = TAILQ_FIRST(&_dlsym_search_list)) != NULL) {
+ TAILQ_REMOVE(&_dlsym_search_list, n, next_sib);
+ n->data->obj_global = 0; /* clear the cached global flag */
+ _dl_free(n);
+ }
+
+ /* rebuild list */
+ _dl_newsymsearch();
+ /*
+ * search dlopened objects: global or req_obj == dlopened_obj
+ * and and it's children
+ */
+
+ _dl_newsymsearch();
+
+ TAILQ_FOREACH(n, &_dlopened_child_list, next_sib) {
+ childlistlen++;
+#if 0
+ DL_DEB(("opened list: %s\n", n->data->load_name));
+#endif
+ global = n->data->obj_flags & RTLD_GLOBAL;
+
+ if (n->data->lastlookup == _dl_searchnum)
+ continue;
+
+ grouplistlen = 0;
+ TAILQ_FOREACH(m, &n->data->grpsym_list, next_sib) {
+ grouplistlen++;
+ if (m->data->lastlookup == _dl_searchnum)
+ continue;
+ if (!global && m->data != n->data) {
+ continue;
+ }
+ m->data->obj_global |= global & RTLD_GLOBAL;
+
+ _dl_append_search(m->data);
+ }
+ }
+ if (grouplistlen > maxgrouplist) {
+ maxgrouplist = grouplistlen ;
+ DL_DEB(("maxgrouplist = %d\n", maxgrouplist));
+ }
+ if (childlistlen > maxchildlist) {
+ maxchildlist = childlistlen;
+ DL_DEB(("maxchildlist = %d\n", maxchildlist));
+ }
+
+#if 0
+ TAILQ_FOREACH(n, &_dlsym_search_list, next_sib) {
+ DL_DEB(("objects: %s global %d\n",
+ n->data->load_name,
+ n->data->obj_global));
+ }
+#endif
+
+ _dl_search_list_valid = 1;
+}
+
+void
+_dl_append_search(elf_object_t *object)
+{
+ struct dep_node *n;
+ n = _dl_malloc(sizeof *n);
+ n->data = object;
+
+ object->lastlookup = _dl_searchnum;
+ TAILQ_INSERT_TAIL(&_dlsym_search_list, n, next_sib);
+}
+
void
_dl_remove_object(elf_object_t *object)
{
@@ -322,6 +406,8 @@ _dl_find_symbol(const char *name, const
const char *p = name;
elf_object_t *object = NULL, *weak_object = NULL;
int found = 0;
+ int visit = 0;
+ static int maxvisit = 0;
struct dep_node *n, *m;
@@ -372,14 +458,12 @@ _dl_find_symbol(const char *name, const
}
}
}
- } else {
+ } else if ((flags &
(SYM_SEARCH_NEXT|SYM_SEARCH_SELF|SYM_SEARCH_OTHER))) {
int skip = 0;
if ((flags & SYM_SEARCH_SELF) || (flags & SYM_SEARCH_NEXT))
skip = 1;
- _dl_newsymsearch();
-
/*
* search dlopened objects: global or req_obj == dlopened_obj
* and and it's children
@@ -389,7 +473,6 @@ _dl_find_symbol(const char *name, const
(n->data != req_obj->load_object))
continue;
- n->data->lastlookup_head = _dl_searchnum;
TAILQ_FOREACH(m, &n->data->grpsym_list, next_sib) {
if (skip == 1) {
if (m->data == req_obj) {
@@ -402,7 +485,6 @@ _dl_find_symbol(const char *name, const
if ((flags & SYM_SEARCH_OTHER) &&
(m->data == req_obj))
continue;
- m->data->lastlookup = _dl_searchnum;
if (_dl_find_symbol_obj(m->data, name, h, flags,
this, &weak_sym, &weak_object)) {
object = m->data;
@@ -411,9 +493,46 @@ _dl_find_symbol(const char *name, const
}
}
}
+ } else {
+ if (_dl_search_list_valid == 0) {
+ _dl_rebuild_allobj_grouplist();
+ }
+
+ TAILQ_FOREACH(n, &_dlsym_search_list, next_sib) {
+ if (n->data == req_obj->load_object) {
+ TAILQ_FOREACH(m, &n->data->grpsym_list,
+ next_sib) {
+ visit++;
+ if (_dl_find_symbol_obj(m->data, name,
+ h, flags, this, &weak_sym,
+ &weak_object)) {
+ object = m->data;
+ found = 1;
+ goto found;
+ }
+ }
+ }
+ if (((n->data->obj_global & RTLD_GLOBAL) == 0) &&
+ (n->data != req_obj->load_object))
+ continue;
+
+ //DL_DEB(("searching for %s in %s\n", name,
n->data->load_name));
+ visit++;
+ if (_dl_find_symbol_obj(n->data, name, h, flags,
+ this, &weak_sym, &weak_object)) {
+ object = n->data;
+ found = 1;
+ DL_DEB(("sym %s is in %s\n", name,
object->load_name));
+ goto found;
+ }
+ }
}
found:
+ if (visit > maxvisit) {
+ maxvisit = visit;
+ DL_DEB(("maxvisit is %d\n", maxvisit));
+ }
if (weak_object != NULL && found == 0) {
object=weak_object;
*this = weak_sym;
Index: resolve.h
===================================================================
RCS file: /cvs/src/libexec/ld.so/resolve.h,v
retrieving revision 1.62
diff -u -p -r1.62 resolve.h
--- resolve.h 25 Oct 2010 20:34:44 -0000 1.62
+++ resolve.h 17 Apr 2011 14:51:06 -0000
@@ -43,6 +43,8 @@ struct load_list {
long foff;
};
+TAILQ_HEAD(dep_node_head, dep_node);
+
/*
* Structure describing a loaded object.
* The head of this struct must be compatible
@@ -115,6 +117,7 @@ struct elf_object {
#define OBJTYPE_LIB 3
#define OBJTYPE_DLO 4
int obj_flags;
+ int obj_global;
Elf_Word *buckets;
u_int32_t nbuckets;
@@ -122,9 +125,9 @@ struct elf_object {
u_int32_t nchains;
Elf_Dyn *dynamic;
- TAILQ_HEAD(,dep_node) child_list; /* direct dep libs of object */
- TAILQ_HEAD(,dep_node) grpsym_list; /* ordered complete dep list */
- TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */
+ struct dep_node_head child_list; /* direct dep libs of object */
+ struct dep_node_head grpsym_list; /* ordered complete dep list */
+ struct dep_node_head grpref_list; /* refs to other load groups */
int refcount; /* dep libs only */
int opencount; /* # dlopen() & exe */
@@ -233,6 +236,7 @@ extern elf_object_t *_dl_objects;
extern elf_object_t *_dl_last_object;
extern elf_object_t *_dl_loading_object;
+void _dl_append_search(elf_object_t *object);
extern const char *_dl_progname;
extern struct r_debug *_dl_debug_map;
@@ -278,6 +282,7 @@ extern int _dl_symcachestat_hits;
extern int _dl_symcachestat_lookups;
TAILQ_HEAD(dlochld, dep_node);
extern struct dlochld _dlopened_child_list;
+extern int _dl_search_list_valid;
/* variables used to avoid duplicate node checking */
int _dl_searchnum;
Dale Rahn dr...@dalerahn.com
