From: Pieter Smith <pieter@boesman.nl>
To: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Josh Triplett" <josh@joshtriplett.org>,
"Pieter Smith" <pieter@boesman.nl>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Eric Paris" <eparis@redhat.com>,
"Matt Turner" <mattst88@gmail.com>,
"Michal Hocko" <mhocko@suse.cz>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
"Fabian Frederick" <fabf@skynet.be>, "Tejun Heo" <tj@kernel.org>,
蔡正龙 <zhenglong.cai@cs2c.com.cn>,
"Luis R. Rodriguez" <mcgrof@suse.com>,
"Peter Foley" <pefoley2@pefoley.com>,
"Konstantin Khlebnikov" <koct9i@gmail.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"H. Peter Anvin" <hpa@zytor.com>,
"Oleg Nesterov" <oleg@redhat.com>,
"Andy Lutomirski" <luto@amacapital.net>,
"David Herrmann" <dh.herrmann@gmail.com>,
"Kees Cook" <keescook@chromium.org>,
linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org (open list),
linux-api@vger.kernel.org (open list:ABI/API)
Subject: [PATCH 2/2] fs: Support compiling out sendfile
Date: Mon, 20 Oct 2014 23:48:37 +0200 [thread overview]
Message-ID: <1413841728-1313-2-git-send-email-pieter@boesman.nl> (raw)
In-Reply-To: <1413841728-1313-1-git-send-email-pieter@boesman.nl>
Many embedded systems will not need this syscall, and omitting it
saves space. Add a new EXPERT config option CONFIG_SENDFILE_SYSCALL
(default y) to support compiling it out.
bloat-o-meter:
add/remove: 0/4 grow/shrink: 5/0 up/down: 23/-751 (-728)
function old new delta
sys_pwritev 115 122 +7
sys_preadv 115 122 +7
fdput_pos 29 36 +7
sys_pwrite64 115 116 +1
sys_pread64 115 116 +1
fdput 11 - -11
sys_sendfile 122 - -122
sys_sendfile64 126 - -126
do_sendfile 492 - -492
Signed-off-by: Pieter Smith <pieter@boesman.nl>
---
fs/Makefile | 3 ++-
init/Kconfig | 10 ++++++++++
kernel/sys_ni.c | 4 ++++
3 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/fs/Makefile b/fs/Makefile
index 1e3423f..1bbfea7 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -5,7 +5,7 @@
# Rewritten to use lists instead of if-statements.
#
-obj-y := open.o read_write.o sendfile.o file_table.o super.o \
+obj-y := open.o read_write.o file_table.o super.o \
char_dev.o stat.o exec.o pipe.o namei.o fcntl.o \
ioctl.o readdir.o select.o dcache.o inode.o \
attr.o bad_inode.o file.o filesystems.o namespace.o \
@@ -38,6 +38,7 @@ obj-$(CONFIG_COMPAT_BINFMT_ELF) += compat_binfmt_elf.o
obj-$(CONFIG_BINFMT_ELF_FDPIC) += binfmt_elf_fdpic.o
obj-$(CONFIG_BINFMT_SOM) += binfmt_som.o
obj-$(CONFIG_BINFMT_FLAT) += binfmt_flat.o
+obj-$(CONFIG_SENDFILE_SYSCALL) += sendfile.o
obj-$(CONFIG_FS_MBCACHE) += mbcache.o
obj-$(CONFIG_FS_POSIX_ACL) += posix_acl.o
diff --git a/init/Kconfig b/init/Kconfig
index 782a65b..df6785c 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1547,6 +1547,16 @@ config ADVISE_SYSCALLS
applications use these syscalls, you can disable this option to save
space.
+config SENDFILE_SYSCALL
+ bool "Enable sendfile syscall" if EXPERT
+ default y
+ help
+ This option enables the sendfile syscall, used by applications to copy
+ data between file descriptors. Because sendfile performs the copying
+ within the kernel, it is more efficient than the combination of read
+ and write. If building an embedded system where no applications use
+ the sendfile syscall, you can disable this option to save space.
+
config PCI_QUIRKS
default y
bool "Enable PCI quirk workarounds" if EXPERT
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index d4709d4..b068de7 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -159,6 +159,10 @@ cond_syscall(sys_uselib);
cond_syscall(sys_fadvise64);
cond_syscall(sys_fadvise64_64);
cond_syscall(sys_madvise);
+cond_syscall(sys_sendfile);
+cond_syscall(sys_sendfile64);
+cond_syscall(compat_sys_sendfile);
+cond_syscall(compat_sys_sendfile64);
/* arch-specific weak syscall entries */
cond_syscall(sys_pciconfig_read);
--
1.9.1
next prev parent reply other threads:[~2014-10-20 21:49 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-20 21:48 [PATCH 1/2] fs: Moved sendfile syscall to own source file Pieter Smith
2014-10-20 21:48 ` Pieter Smith [this message]
2014-10-20 22:24 ` [PATCH 2/2] fs: Support compiling out sendfile josh
2014-10-21 7:51 ` Christoph Hellwig
2014-10-21 9:04 ` Josh Triplett
2014-10-21 9:13 ` Christoph Hellwig
2014-10-21 9:50 ` Josh Triplett
[not found] ` <54467D9C.2030302@zytor.com>
[not found] ` <20141021171814.GA14704@cloud>
2014-10-21 17:20 ` Eric Paris
2014-10-20 22:03 ` [PATCH 1/2] fs: Moved sendfile syscall to own source file josh
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