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Remove __ASSUME_COMPLETE_READV_WRITEV.

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This patch removes the __ASSUME_COMPLETE_READV_WRITEV
kernel-features.h macro, now that it can be unconditionally assumed to
be true.  (The relevant kernel feature was added some time between 2.0
and 2.2, and this macro is only used in sysdeps/unix/sysv/linux/.)

Tested x86_64 that the disassembly of installed shared libraries is
unchanged by this patch.

	* sysdeps/unix/sysv/linux/kernel-features.h
	(__ASSUME_COMPLETE_READV_WRITEV): Remove macro.
	* sysdeps/unix/sysv/linux/readv.c: Do not include
	<kernel-features.h>.
	[!__ASSUME_COMPLETE_READV_WRITEV]: Remove conditional code.
	[!UIO_FASTIOV] (UIO_FASTIOV): Remove macro.
	(__libc_readv) [__ASSUME_COMPLETE_READV_WRITEV]: Make code
	unconditional.
	(__libc_readv) [!__ASSUME_COMPLETE_READV_WRITEV]: Remove
	conditional code.
	* sysdeps/unix/sysv/linux/writev.c: Do not include
	<kernel-features.h>.
	[!__ASSUME_COMPLETE_READV_WRITEV]: Remove conditional code.
	[!UIO_FASTIOV] (UIO_FASTIOV): Remove macro.
	(__libc_writev) [__ASSUME_COMPLETE_READV_WRITEV]: Make code
	unconditional.
	(__libc_writev) [!__ASSUME_COMPLETE_READV_WRITEV]: Remove
	conditional code.
This commit is contained in:
Joseph Myers 2014-06-25 11:31:51 +00:00
parent c7aec4beb1
commit 0f5b71850e
4 changed files with 23 additions and 52 deletions
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21
ChangeLog
View File

@ -1,3 +1,24 @@
2014-06-25 Joseph Myers <joseph@codesourcery.com>
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_COMPLETE_READV_WRITEV): Remove macro.
* sysdeps/unix/sysv/linux/readv.c: Do not include
<kernel-features.h>.
[!__ASSUME_COMPLETE_READV_WRITEV]: Remove conditional code.
[!UIO_FASTIOV] (UIO_FASTIOV): Remove macro.
(__libc_readv) [__ASSUME_COMPLETE_READV_WRITEV]: Make code
unconditional.
(__libc_readv) [!__ASSUME_COMPLETE_READV_WRITEV]: Remove
conditional code.
* sysdeps/unix/sysv/linux/writev.c: Do not include
<kernel-features.h>.
[!__ASSUME_COMPLETE_READV_WRITEV]: Remove conditional code.
[!UIO_FASTIOV] (UIO_FASTIOV): Remove macro.
(__libc_writev) [__ASSUME_COMPLETE_READV_WRITEV]: Make code
unconditional.
(__libc_writev) [!__ASSUME_COMPLETE_READV_WRITEV]: Remove
conditional code.
2014-06-25 Will Newton <will.newton@linaro.org> 2014-06-25 Will Newton <will.newton@linaro.org>
* sysdeps/posix/tempname.c: Merge from gnulib, cosmetic * sysdeps/posix/tempname.c: Merge from gnulib, cosmetic

5
sysdeps/unix/sysv/linux/kernel-features.h
View File

@ -94,11 +94,6 @@
# define __ASSUME_SET_ROBUST_LIST 1 # define __ASSUME_SET_ROBUST_LIST 1
#endif #endif
/* Pessimistically assume that 2.6.18 introduced real handling of
large numbers of requests to readv and writev and that we don't
need a fallback. It likely worked for much longer. */
#define __ASSUME_COMPLETE_READV_WRITEV 1
/* Support for PI futexes was added in 2.6.18 (but some architectures /* Support for PI futexes was added in 2.6.18 (but some architectures
lack futex_atomic_cmpxchg_inatomic in some configurations). */ lack futex_atomic_cmpxchg_inatomic in some configurations). */
#if !(defined __sparc__ && !defined __arch64__ && !defined __sparc_v9__) #if !(defined __sparc__ && !defined __arch64__ && !defined __sparc_v9__)

25
sysdeps/unix/sysv/linux/readv.c
View File

@ -23,19 +23,8 @@
#include <sysdep-cancel.h> #include <sysdep-cancel.h>
#include <sys/syscall.h> #include <sys/syscall.h>
#include <kernel-features.h>
#ifndef __ASSUME_COMPLETE_READV_WRITEV
static ssize_t __atomic_readv_replacement (int, const struct iovec *,
int) internal_function;
#endif
/* Not all versions of the kernel support the large number of records. */
#ifndef UIO_FASTIOV
# define UIO_FASTIOV 8 /* 8 is a safe number. */
#endif
/* Consider moving to syscalls.list. */
ssize_t ssize_t
__libc_readv (fd, vector, count) __libc_readv (fd, vector, count)
@ -56,19 +45,7 @@ __libc_readv (fd, vector, count)
LIBC_CANCEL_RESET (oldtype); LIBC_CANCEL_RESET (oldtype);
} }
#ifdef __ASSUME_COMPLETE_READV_WRITEV
return result; return result;
#else
if (result >= 0 || errno != EINVAL || count <= UIO_FASTIOV)
return result;
return __atomic_readv_replacement (fd, vector, count);
#endif
} }
strong_alias (__libc_readv, __readv) strong_alias (__libc_readv, __readv)
weak_alias (__libc_readv, readv) weak_alias (__libc_readv, readv)
#ifndef __ASSUME_COMPLETE_READV_WRITEV
# define __libc_readv static internal_function __atomic_readv_replacement
# include <sysdeps/posix/readv.c>
#endif

24
sysdeps/unix/sysv/linux/writev.c
View File

@ -23,19 +23,9 @@
#include <sysdep-cancel.h> #include <sysdep-cancel.h>
#include <sys/syscall.h> #include <sys/syscall.h>
#include <kernel-features.h>
#ifndef __ASSUME_COMPLETE_READV_WRITEV
static ssize_t __atomic_writev_replacement (int, const struct iovec *,
int) internal_function;
#endif
/* Not all versions of the kernel support the large number of records. */ /* Consider moving to syscalls.list. */
#ifndef UIO_FASTIOV
# define UIO_FASTIOV 8 /* 8 is a safe number. */
#endif
ssize_t ssize_t
__libc_writev (fd, vector, count) __libc_writev (fd, vector, count)
@ -56,19 +46,7 @@ __libc_writev (fd, vector, count)
LIBC_CANCEL_RESET (oldtype); LIBC_CANCEL_RESET (oldtype);
} }
#ifdef __ASSUME_COMPLETE_READV_WRITEV
return result; return result;
#else
if (result >= 0 || errno != EINVAL || count <= UIO_FASTIOV)
return result;
return __atomic_writev_replacement (fd, vector, count);
#endif
} }
strong_alias (__libc_writev, __writev) strong_alias (__libc_writev, __writev)
weak_alias (__libc_writev, writev) weak_alias (__libc_writev, writev)
#ifndef __ASSUME_COMPLETE_READV_WRITEV
# define __libc_writev static internal_function __atomic_writev_replacement
# include <sysdeps/posix/writev.c>
#endif