Update.

	* sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_VFORK_SYSCALL):
	Define for 2.4+ kernels.

	* sysdeps/unix/sysv/linux/i386/vfork.S: Optimize for kernels which
	are known to have the vfork syscall.  Don't confuse the CPUs
	branch prediction unit by jumping to the return address.

diff --git a/ChangeLog b/ChangeLog
index 5283a65..95c8038 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -70,6 +70,13 @@
 
 2002-10-15  Ulrich Drepper  <drepper@redhat.com>
 
+       * sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_VFORK_SYSCALL):
+       Define for 2.4+ kernels.
+
+       * sysdeps/unix/sysv/linux/i386/vfork.S: Optimize for kernels which
+       are known to have the vfork syscall.  Don't confuse the CPUs
+       branch prediction unit by jumping to the return address.
+
        * sysdeps/unix/sysv/linux/alpha/fpathconf.c (__fpathconf): Add
        support for reiserfs and xfs.
 

diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index a8145e1..0796a8a 100644 (file)
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -214,6 +214,11 @@
 # define __ASSUME_SET_THREAD_AREA_SYSCALL      1
 #endif
 
+/* The vfork syscall on x86 was definitely available in 2.4.  */
+#if __LINUX_KERNEL_VERSION >= 132097 && defined __i386__
+# define __ASSUME_VFORK_SYSCALL                1
+#endif
+
 /* There are an infinite number of PA-RISC kernel versions numbered
    2.4.0.  But they've not really been released as such.  We require
    and expect the final version here.  */