glibc/glibc-tls-getaddr.patch
Jakub Jelinek 456c7dc140 2.8-7
2008-07-08 16:46:35 +00:00

124 lines
3.7 KiB
Diff

2008-05-11 Ulrich Drepper <drepper@redhat.com>
* elf/dl-tls.c (__tls_get_addr): Optimize by moving slow path in
its own function. This reduces the frame setup costs and more.
--- libc/elf/dl-tls.c 8 Mar 2008 06:11:58 -0000 1.6
+++ libc/elf/dl-tls.c 12 May 2008 05:35:52 -0000 1.7
@@ -691,6 +691,61 @@ _dl_update_slotinfo (unsigned long int r
}
+static void *
+__attribute_noinline__
+tls_get_addr_tail (dtv_t *dtv, struct link_map *the_map, size_t module)
+{
+ /* The allocation was deferred. Do it now. */
+ if (the_map == NULL)
+ {
+ /* Find the link map for this module. */
+ size_t idx = module;
+ struct dtv_slotinfo_list *listp = GL(dl_tls_dtv_slotinfo_list);
+
+ while (idx >= listp->len)
+ {
+ idx -= listp->len;
+ listp = listp->next;
+ }
+
+ the_map = listp->slotinfo[idx].map;
+ }
+
+ again:
+ /* Make sure that, if a dlopen running in parallel forces the
+ variable into static storage, we'll wait until the address in the
+ static TLS block is set up, and use that. If we're undecided
+ yet, make sure we make the decision holding the lock as well. */
+ if (__builtin_expect (the_map->l_tls_offset
+ != FORCED_DYNAMIC_TLS_OFFSET, 0))
+ {
+ __rtld_lock_lock_recursive (GL(dl_load_lock));
+ if (__builtin_expect (the_map->l_tls_offset == NO_TLS_OFFSET, 1))
+ {
+ the_map->l_tls_offset = FORCED_DYNAMIC_TLS_OFFSET;
+ __rtld_lock_unlock_recursive (GL(dl_load_lock));
+ }
+ else
+ {
+ __rtld_lock_unlock_recursive (GL(dl_load_lock));
+ if (__builtin_expect (the_map->l_tls_offset
+ != FORCED_DYNAMIC_TLS_OFFSET, 1))
+ {
+ void *p = dtv[module].pointer.val;
+ if (__builtin_expect (p == TLS_DTV_UNALLOCATED, 0))
+ goto again;
+
+ return p;
+ }
+ }
+ }
+ void *p = dtv[module].pointer.val = allocate_and_init (the_map);
+ dtv[module].pointer.is_static = false;
+
+ return p;
+}
+
+
/* The generic dynamic and local dynamic model cannot be used in
statically linked applications. */
void *
@@ -703,52 +758,10 @@ __tls_get_addr (GET_ADDR_ARGS)
if (__builtin_expect (dtv[0].counter != GL(dl_tls_generation), 0))
the_map = _dl_update_slotinfo (GET_ADDR_MODULE);
- retry:
p = dtv[GET_ADDR_MODULE].pointer.val;
if (__builtin_expect (p == TLS_DTV_UNALLOCATED, 0))
- {
- /* The allocation was deferred. Do it now. */
- if (the_map == NULL)
- {
- /* Find the link map for this module. */
- size_t idx = GET_ADDR_MODULE;
- struct dtv_slotinfo_list *listp = GL(dl_tls_dtv_slotinfo_list);
-
- while (idx >= listp->len)
- {
- idx -= listp->len;
- listp = listp->next;
- }
-
- the_map = listp->slotinfo[idx].map;
- }
-
- /* Make sure that, if a dlopen running in parallel forces the
- variable into static storage, we'll wait until the address in
- the static TLS block is set up, and use that. If we're
- undecided yet, make sure we make the decision holding the
- lock as well. */
- if (__builtin_expect (the_map->l_tls_offset
- != FORCED_DYNAMIC_TLS_OFFSET, 0))
- {
- __rtld_lock_lock_recursive (GL(dl_load_lock));
- if (__builtin_expect (the_map->l_tls_offset == NO_TLS_OFFSET, 1))
- {
- the_map->l_tls_offset = FORCED_DYNAMIC_TLS_OFFSET;
- __rtld_lock_unlock_recursive (GL(dl_load_lock));
- }
- else
- {
- __rtld_lock_unlock_recursive (GL(dl_load_lock));
- if (__builtin_expect (the_map->l_tls_offset
- != FORCED_DYNAMIC_TLS_OFFSET, 1))
- goto retry;
- }
- }
- p = dtv[GET_ADDR_MODULE].pointer.val = allocate_and_init (the_map);
- dtv[GET_ADDR_MODULE].pointer.is_static = false;
- }
+ p = tls_get_addr_tail (dtv, the_map, GET_ADDR_MODULE);
return (char *) p + GET_ADDR_OFFSET;
}