Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754980AbbLVSDD (ORCPT ); Tue, 22 Dec 2015 13:03:03 -0500 Received: from mail.efficios.com ([78.47.125.74]:57827 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752096AbbLVSDA (ORCPT ); Tue, 22 Dec 2015 13:03:00 -0500 From: Mathieu Desnoyers To: Paul Turner , Andrew Hunter , Thomas Gleixner , Michael Kerrisk , Russell King Cc: linux-kernel@vger.kernel.org, Mathieu Desnoyers , Catalin Marinas , Will Deacon , Peter Zijlstra , Andy Lutomirski , Andi Kleen , Dave Watson , Chris Lameter , Ingo Molnar , Ben Maurer , Steven Rostedt , "Paul E. McKenney" , Josh Triplett , Linus Torvalds , Andrew Morton , linux-api@vger.kernel.org Subject: [RFC PATCH v2 3/3] thread_local_abi: wire up ARM system call Date: Tue, 22 Dec 2015 13:02:13 -0500 Message-Id: <1450807333-22104-3-git-send-email-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1450807333-22104-1-git-send-email-mathieu.desnoyers@efficios.com> References: <1450807333-22104-1-git-send-email-mathieu.desnoyers@efficios.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2931 Lines: 81 Wire up the thread local ABI on ARM32. Call the thread_local_abi_handle_notify_resume() function on return to userspace if TIF_NOTIFY_RESUME thread flag is set. This provides an ABI improving the speed of a getcpu operation on ARM by skipping the getcpu system call on the fast path. [ Untested. ] 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: Thomas Gleixner CC: linux-api@vger.kernel.org --- arch/arm/include/uapi/asm/unistd.h | 1 + arch/arm/kernel/calls.S | 1 + arch/arm/kernel/signal.c | 2 ++ 3 files changed, 4 insertions(+) diff --git a/arch/arm/include/uapi/asm/unistd.h b/arch/arm/include/uapi/asm/unistd.h index 7a2a32a..859433a 100644 --- a/arch/arm/include/uapi/asm/unistd.h +++ b/arch/arm/include/uapi/asm/unistd.h @@ -416,6 +416,7 @@ #define __NR_execveat (__NR_SYSCALL_BASE+387) #define __NR_userfaultfd (__NR_SYSCALL_BASE+388) #define __NR_membarrier (__NR_SYSCALL_BASE+389) +#define __NR_thread_local_abi (__NR_SYSCALL_BASE+390) /* * The following SWIs are ARM private. diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S index fde6c88..82b59cc 100644 --- a/arch/arm/kernel/calls.S +++ b/arch/arm/kernel/calls.S @@ -399,6 +399,7 @@ CALL(sys_execveat) CALL(sys_userfaultfd) CALL(sys_membarrier) +/* 390 */ CALL(sys_thread_local_abi) #ifndef syscalls_counted .equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls #define syscalls_counted diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index 7b8f214..c64cd2f 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -594,6 +594,8 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall) } else { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + if (thread_local_abi_active(current)) + thread_local_abi_handle_notify_resume(current); } } local_irq_disable(); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/