[PATCH v2] Consolidate Linux readahead() implementations
Yury Norov
ynorov@caviumnetworks.com
Sun Sep 25 11:38:00 GMT 2016
There are 4 different implementations of readahead() in glibc:
- arm and mips32 use one located under sysdeps/unix/sysv/linux/arm;
- powerpc32 and wordsize64 has 2 another implementations in their
syscalls.list;
- and there's generic implementation under sysdeps/unix/sysv/linux for
other ports.
With the [1] it's possible to consolidate all of them except tile32
under sysdeps/unix/sysv/linux. Tile32 like other 32-bit ports passes
offset in a pair of registers, but doesn't need register alignment,
though has __ASSUME_ALIGNED_REGISTER_PAIRS enabled. So it should be
handled as exception.
[1] https://sourceware.org/ml/libc-alpha/2016-09/msg00452.html
v2:
- remove powerpc and wordsize64 implementations;
- remove __ASSUME_READAHEAD_ALIGN option;
- add exception for tile32.
v1: https://sourceware.org/ml/libc-alpha/2016-09/msg00469.html
2016-09-25: Yury Norov <ynorov@caviumnetworks.com>
* sysdeps/unix/sysv/linux/mips/mips32/readahead.c: Delete.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/syscalls.list: Delete
readahead generation.
* sysdeps/unix/sysv/linux/wordsize-64/syscalls.list: Likewise.
* sysdeps/unix/sysv/linux/readahead.c: Consolidate implementation.
* sysdeps/unix/sysv/linux/tile/readahead.c: New file for
exceptional readahead() implementation.
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
CC: Adhemerval Zanella <adhemerval.zanella@linaro.org>
CC: Florian Weimer <fw@deneb.enyo.de>
---
sysdeps/unix/sysv/linux/arm/readahead.c | 37 ----------------------
sysdeps/unix/sysv/linux/mips/mips32/readahead.c | 1 -
.../sysv/linux/powerpc/powerpc32/syscalls.list | 3 --
sysdeps/unix/sysv/linux/readahead.c | 6 ++--
sysdeps/unix/sysv/linux/tile/readahead.c | 26 +++++++++++++++
sysdeps/unix/sysv/linux/wordsize-64/syscalls.list | 1 -
6 files changed, 28 insertions(+), 46 deletions(-)
delete mode 100644 sysdeps/unix/sysv/linux/arm/readahead.c
delete mode 100644 sysdeps/unix/sysv/linux/mips/mips32/readahead.c
create mode 100644 sysdeps/unix/sysv/linux/tile/readahead.c
diff --git a/sysdeps/unix/sysv/linux/arm/readahead.c b/sysdeps/unix/sysv/linux/arm/readahead.c
deleted file mode 100644
index 9824e6f..0000000
--- a/sysdeps/unix/sysv/linux/arm/readahead.c
+++ /dev/null
@@ -1,37 +0,0 @@
-/* Provide kernel hint to read ahead.
- Copyright (C) 2002-2016 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library. If not, see
- <http://www.gnu.org/licenses/>. */
-
-#include <errno.h>
-#include <fcntl.h>
-#include <sys/types.h>
-#include <endian.h>
-
-#include <sysdep.h>
-#include <sys/syscall.h>
-
-
-ssize_t
-__readahead (int fd, off64_t offset, size_t count)
-{
- return INLINE_SYSCALL (readahead, 5, fd, 0,
- __LONG_LONG_PAIR ((off_t) (offset >> 32),
- (off_t) (offset & 0xffffffff)),
- count);
-}
-
-weak_alias (__readahead, readahead)
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/readahead.c b/sysdeps/unix/sysv/linux/mips/mips32/readahead.c
deleted file mode 100644
index 80170c3..0000000
--- a/sysdeps/unix/sysv/linux/mips/mips32/readahead.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/unix/sysv/linux/arm/readahead.c>
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/syscalls.list b/sysdeps/unix/sysv/linux/powerpc/powerpc32/syscalls.list
index 451d508..487bdd0 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/syscalls.list
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/syscalls.list
@@ -7,8 +7,5 @@ lchown - lchown i:sii __lchown lchown@@GLIBC_2.0 chown@GLIBC_2.0
oldgetrlimit EXTRA getrlimit i:ip __old_getrlimit getrlimit@GLIBC_2.0
setrlimit - setrlimit i:ip __setrlimit setrlimit@GLIBC_2.0 setrlimit@@GLIBC_2.2
-# Due to 64bit alignment there is a dummy second parameter
-readahead - readahead i:iiiii __readahead readahead
-
prlimit64 EXTRA prlimit64 i:iipp prlimit64
fanotify_mark EXTRA fanotify_mark i:iiiiis fanotify_mark
diff --git a/sysdeps/unix/sysv/linux/readahead.c b/sysdeps/unix/sysv/linux/readahead.c
index 92e5428..ced289b 100644
--- a/sysdeps/unix/sysv/linux/readahead.c
+++ b/sysdeps/unix/sysv/linux/readahead.c
@@ -29,10 +29,8 @@
ssize_t
__readahead (int fd, off64_t offset, size_t count)
{
- return INLINE_SYSCALL (readahead, 4, fd,
- __LONG_LONG_PAIR ((off_t) (offset >> 32),
- (off_t) (offset & 0xffffffff)),
- count);
+ return INLINE_SYSCALL_CALL (readahead, fd, __ALIGNMENT_ARG
+ SYSCALL_LL64 (offset), count);
}
#else
ssize_t
diff --git a/sysdeps/unix/sysv/linux/tile/readahead.c b/sysdeps/unix/sysv/linux/tile/readahead.c
new file mode 100644
index 0000000..05d7822
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tile/readahead.c
@@ -0,0 +1,26 @@
+/* Provide kernel hint to read ahead.
+ Copyright (C) 2002-2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+#ifndef _LP64
+# undef __ALIGNMENT_ARG
+# define __ALIGNMENT_ARG
+#endif
+
+#include <sysdeps/unix/sysv/linux/readahead.c>
diff --git a/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list b/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
index 3f3569f..1040e70 100644
--- a/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
+++ b/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
@@ -7,7 +7,6 @@ ftruncate - ftruncate i:ii __ftruncate ftruncate ftruncate64 __ftruncate64
truncate - truncate i:si truncate truncate64
getrlimit - getrlimit i:ip __getrlimit getrlimit getrlimit64 __getrlimit64
setrlimit - setrlimit i:ip __setrlimit setrlimit setrlimit64
-readahead - readahead i:iii __readahead readahead
sendfile - sendfile i:iipi sendfile sendfile64
sync_file_range - sync_file_range Ci:iiii sync_file_range
creat - creat Ci:si creat creat64
--
2.7.4
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