[PATCH 0/3] readfile(2): a new syscall to make open/read/close faster

Greg Kroah-Hartman
2020-07-04T14:03:14Z

Here is a tiny new syscall, readfile, that makes it simpler to read
small/medium sized files all in one shot, no need to do open/read/close.
This is especially helpful for tools that poke around in procfs or
sysfs, making a little bit of a less system load than before, especially
as syscall overheads go up over time due to various CPU bugs being
addressed.

There are 4 patches in this series, the first 3 are against the kernel
tree, adding the syscall logic, wiring up the syscall, and adding some
tests for it.

The last patch is agains the man-pages project, adding a tiny man page
to try to describe the new syscall.

Greg Kroah-Hartman (3):
readfile: implement readfile syscall
arch: wire up the readfile syscall
selftests: add readfile(2) selftests

arch/alpha/kernel/syscalls/syscall.tbl | 1 +
arch/arm/tools/syscall.tbl | 1 +
arch/arm64/include/asm/unistd.h | 2 +-
arch/arm64/include/asm/unistd32.h | 2 +
arch/ia64/kernel/syscalls/syscall.tbl | 1 +
arch/m68k/kernel/syscalls/syscall.tbl | 1 +
arch/microblaze/kernel/syscalls/syscall.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n32.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n64.tbl | 1 +
arch/mips/kernel/syscalls/syscall_o32.tbl | 1 +
arch/parisc/kernel/syscalls/syscall.tbl | 1 +
arch/powerpc/kernel/syscalls/syscall.tbl | 1 +
arch/s390/kernel/syscalls/syscall.tbl | 1 +
arch/sh/kernel/syscalls/syscall.tbl | 1 +
arch/sparc/kernel/syscalls/syscall.tbl | 1 +
arch/x86/entry/syscalls/syscall_32.tbl | 1 +
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
arch/xtensa/kernel/syscalls/syscall.tbl | 1 +
fs/open.c | 50 +++
include/linux/syscalls.h | 2 +
include/uapi/asm-generic/unistd.h | 4 +-
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/readfile/.gitignore | 3 +
tools/testing/selftests/readfile/Makefile | 7 +
tools/testing/selftests/readfile/readfile.c | 285 +++++++++++++++++
.../selftests/readfile/readfile_speed.c | 301 ++++++++++++++++++
26 files changed, 671 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/readfile/.gitignore
create mode 100644 tools/testing/selftests/readfile/Makefile
create mode 100644 tools/testing/selftests/readfile/readfile.c
create mode 100644 tools/testing/selftests/readfile/readfile_speed.c

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2.27.0