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author | jdp <jdp@FreeBSD.org> | 2001-05-05 23:21:05 +0000 |
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committer | jdp <jdp@FreeBSD.org> | 2001-05-05 23:21:05 +0000 |
commit | 66a962ce675f3386156405c78fe7d7a1e6a852bb (patch) | |
tree | 661ed94ee85164ded5139aff0e44eefd488583a9 /libexec/rtld-elf/i386 | |
parent | da4bd71ba54c6cef03c8b248a7dd42b16a7b348e (diff) | |
download | FreeBSD-src-66a962ce675f3386156405c78fe7d7a1e6a852bb.zip FreeBSD-src-66a962ce675f3386156405c78fe7d7a1e6a852bb.tar.gz |
Performance improvements for the ELF dynamic linker. These
particularly help programs which load many shared libraries with
a lot of relocations. Large C++ programs such as are found in KDE
are a prime example.
While relocating a shared object, maintain a vector of symbols
which have already been looked up, directly indexed by symbol
number. Typically, symbols which are referenced by a relocation
entry are referenced by many of them. This is the same optimization
I made to the a.out dynamic linker in 1995 (rtld.c revision 1.30).
Also, compare the first character of a sought-after symbol with its
symbol table entry before calling strcmp().
On a PII/400 these changes reduce the start-up time of a typical
KDE program from 833 msec (elapsed) to 370 msec.
MFC after: 5 days
Diffstat (limited to 'libexec/rtld-elf/i386')
-rw-r--r-- | libexec/rtld-elf/i386/reloc.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/libexec/rtld-elf/i386/reloc.c b/libexec/rtld-elf/i386/reloc.c index 360733a..aff70b0 100644 --- a/libexec/rtld-elf/i386/reloc.c +++ b/libexec/rtld-elf/i386/reloc.c @@ -114,6 +114,11 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld) { const Elf_Rel *rellim; const Elf_Rel *rel; + SymCache *cache; + + cache = (SymCache *)alloca(obj->nchains * sizeof(SymCache)); + if (cache != NULL) + memset(cache, 0, obj->nchains * sizeof(SymCache)); rellim = (const Elf_Rel *) ((caddr_t) obj->rel + obj->relsize); for (rel = obj->rel; rel < rellim; rel++) { @@ -130,7 +135,7 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld) const Obj_Entry *defobj; def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, - false); + false, cache); if (def == NULL) return -1; @@ -149,7 +154,7 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld) const Obj_Entry *defobj; def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, - false); + false, cache); if (def == NULL) return -1; @@ -179,7 +184,7 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld) const Obj_Entry *defobj; def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, - false); + false, cache); if (def == NULL) return -1; @@ -238,7 +243,7 @@ reloc_jmpslots(Obj_Entry *obj) assert(ELF_R_TYPE(rel->r_info) == R_386_JMP_SLOT); where = (Elf_Addr *)(obj->relocbase + rel->r_offset); - def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true); + def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL); if (def == NULL) return -1; reloc_jmpslot(where, (Elf_Addr)(defobj->relocbase + def->st_value)); |