lkml.org 
[lkml]   [2016]   [Apr]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH v6 3/5] Thread-local ABI: wire up ARM system call
Date
Wire up the thread-local ABI system call on 32-bit ARM.

This provides an ABI improving the speed of a getcpu operation
on ARM by skipping the getcpu system call on the fast path.

The thread-local ABI can be extended to add features in the future.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Paul Turner <pjt@google.com>
CC: Andrew Hunter <ahh@google.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andi Kleen <andi@firstfloor.org>
CC: Dave Watson <davejwatson@fb.com>
CC: Chris Lameter <cl@linux.com>
CC: Ingo Molnar <mingo@redhat.com>
CC: Ben Maurer <bmaurer@fb.com>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: linux-api@vger.kernel.org
---
arch/arm/include/asm/unistd.h | 2 +-
arch/arm/include/uapi/asm/unistd.h | 1 +
arch/arm/kernel/calls.S | 3 ++-
3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h
index 7b84657..194b699 100644
--- a/arch/arm/include/asm/unistd.h
+++ b/arch/arm/include/asm/unistd.h
@@ -19,7 +19,7 @@
* This may need to be greater than __NR_last_syscall+1 in order to
* account for the padding in the syscall table
*/
-#define __NR_syscalls (392)
+#define __NR_syscalls (396)

#define __ARCH_WANT_STAT64
#define __ARCH_WANT_SYS_GETHOSTNAME
diff --git a/arch/arm/include/uapi/asm/unistd.h b/arch/arm/include/uapi/asm/unistd.h
index 5dd2528..aaa9221 100644
--- a/arch/arm/include/uapi/asm/unistd.h
+++ b/arch/arm/include/uapi/asm/unistd.h
@@ -418,6 +418,7 @@
#define __NR_membarrier (__NR_SYSCALL_BASE+389)
#define __NR_mlock2 (__NR_SYSCALL_BASE+390)
#define __NR_copy_file_range (__NR_SYSCALL_BASE+391)
+#define __NR_thread_local_abi (__NR_SYSCALL_BASE+392)

/*
* The following SWIs are ARM private.
diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S
index dfc7cd6..d6a0fe9 100644
--- a/arch/arm/kernel/calls.S
+++ b/arch/arm/kernel/calls.S
@@ -399,8 +399,9 @@
CALL(sys_execveat)
CALL(sys_userfaultfd)
CALL(sys_membarrier)
- CALL(sys_mlock2)
+/* 390 */ CALL(sys_mlock2)
CALL(sys_copy_file_range)
+ CALL(sys_thread_local_abi)
#ifndef syscalls_counted
.equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls
#define syscalls_counted
--
2.1.4
\
 
 \ /
  Last update: 2016-04-04 19:21    [W:0.632 / U:0.108 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site