From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Desnoyers Subject: [RFC PATCH v7 4/7] Restartable sequences: wire up ARM 32 system call Date: Thu, 21 Jul 2016 17:14:19 -0400 Message-ID: <1469135662-31512-5-git-send-email-mathieu.desnoyers@efficios.com> References: <1469135662-31512-1-git-send-email-mathieu.desnoyers@efficios.com> Return-path: In-Reply-To: <1469135662-31512-1-git-send-email-mathieu.desnoyers-vg+e7yoeK/dWk0Htik3J/w@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Andrew Morton , Russell King , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Paul Turner , Andrew Hunter , Peter Zijlstra , Andy Lutomirski , Andi Kleen , Dave Watson , Chris Lameter , Ben Maurer , Steven Rostedt , "Paul E. McKenney" , Josh Triplett , Linus Torvalds , Catalin Marinas , Will Deacon , Michael Kerrisk , Boqun Feng , Mathieu Desnoyers List-Id: linux-api@vger.kernel.org Wire up the rseq system call on 32-bit ARM. This provides an ABI improving the speed of a user-space getcpu operation on ARM by skipping the getcpu system call on the fast path, as well as improving the speed of user-space operations on per-cpu data compared to using load-linked/store-conditional. Signed-off-by: Mathieu Desnoyers CC: Russell King CC: Catalin Marinas CC: Will Deacon CC: Thomas Gleixner CC: Paul Turner CC: Andrew Hunter CC: Peter Zijlstra CC: Andy Lutomirski CC: Andi Kleen CC: Dave Watson CC: Chris Lameter CC: Ingo Molnar CC: Ben Maurer CC: Steven Rostedt CC: "Paul E. McKenney" CC: Josh Triplett CC: Linus Torvalds CC: Andrew Morton CC: Boqun Feng CC: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org --- arch/arm/include/uapi/asm/unistd.h | 1 + arch/arm/kernel/calls.S | 1 + 2 files changed, 2 insertions(+) diff --git a/arch/arm/include/uapi/asm/unistd.h b/arch/arm/include/uapi/asm/unistd.h index 2cb9dc7..8f61c79 100644 --- a/arch/arm/include/uapi/asm/unistd.h +++ b/arch/arm/include/uapi/asm/unistd.h @@ -420,6 +420,7 @@ #define __NR_copy_file_range (__NR_SYSCALL_BASE+391) #define __NR_preadv2 (__NR_SYSCALL_BASE+392) #define __NR_pwritev2 (__NR_SYSCALL_BASE+393) +#define __NR_rseq (__NR_SYSCALL_BASE+394) /* * The following SWIs are ARM private. diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S index 703fa0f..0865c04 100644 --- a/arch/arm/kernel/calls.S +++ b/arch/arm/kernel/calls.S @@ -403,6 +403,7 @@ CALL(sys_copy_file_range) CALL(sys_preadv2) CALL(sys_pwritev2) + CALL(sys_rseq) #ifndef syscalls_counted .equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls #define syscalls_counted -- 2.1.4