From 98221c36119d2abfc55fe1d919705f625709fe3b Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sun, 23 Mar 2014 23:19:30 -0400 Subject: [PATCH] reduce static linking overhead from TLS support by inlining mmap syscall the external mmap function is heavy because it has to handle error reporting that the kernel cannot do, and has to do some locking for arcane race-condition-avoidance purposes. for allocating initial TLS, we do not need any of that; the raw syscall suffices. on i386, this change shaves off 13% of the size of .text for the empty program. --- src/env/__init_tls.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/src/env/__init_tls.c b/src/env/__init_tls.c index 5c176811..dbfe62e7 100644 --- a/src/env/__init_tls.c +++ b/src/env/__init_tls.c @@ -5,6 +5,7 @@ #include "pthread_impl.h" #include "libc.h" #include "atomic.h" +#include "syscall.h" #ifndef SHARED @@ -87,8 +88,15 @@ void __init_tls(size_t *aux) libc.tls_size = 2*sizeof(void *)+T.size+T.align+sizeof(struct pthread); - mem = __mmap(0, libc.tls_size, PROT_READ|PROT_WRITE, + mem = (void *)__syscall( +#ifdef SYS_mmap2 + SYS_mmap2, +#else + SYS_mmap, +#endif + 0, libc.tls_size, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); + if (!__install_initial_tls(__copy_tls(mem))) a_crash(); } #else -- GitLab