From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Desnoyers Subject: [RFC PATCH v2 3/3] getcpu_cache: wire up x86 32/64 system call Date: Wed, 27 Jan 2016 11:54:43 -0500 Message-ID: <1453913683-28915-4-git-send-email-mathieu.desnoyers@efficios.com> References: <1453913683-28915-1-git-send-email-mathieu.desnoyers@efficios.com> Return-path: In-Reply-To: <1453913683-28915-1-git-send-email-mathieu.desnoyers@efficios.com> Sender: linux-kernel-owner@vger.kernel.org To: Thomas Gleixner , Paul Turner , Andrew Hunter , Peter Zijlstra Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Andy Lutomirski , Andi Kleen , Dave Watson , Chris Lameter , Ingo Molnar , Ben Maurer , Steven Rostedt , "Paul E. McKenney" , Josh Triplett , Linus Torvalds , Andrew Morton , Russell King , Catalin Marinas , Will Deacon , Michael Kerrisk , Mathieu Desnoyers List-Id: linux-api@vger.kernel.org Wire up the getcpu_cache system call on x86 32/64. Call the getcpu_cache_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 x86 by removing the need to perform a function call, "lsl" instruction, or system call on the fast path. 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/x86/entry/common.c | 1 + arch/x86/entry/syscalls/syscall_32.tbl | 1 + arch/x86/entry/syscalls/syscall_64.tbl | 1 + 3 files changed, 3 insertions(+) diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 0366374..eb6bcae 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -249,6 +249,7 @@ static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags) if (cached_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + getcpu_cache_handle_notify_resume(current); } if (cached_flags & _TIF_USER_RETURN_NOTIFY) diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index f17705e..b3ea491 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -383,3 +383,4 @@ 374 i386 userfaultfd sys_userfaultfd 375 i386 membarrier sys_membarrier 376 i386 mlock2 sys_mlock2 +377 i386 getcpu_cache sys_getcpu_cache diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 314a90b..442aaa0 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -332,6 +332,7 @@ 323 common userfaultfd sys_userfaultfd 324 common membarrier sys_membarrier 325 common mlock2 sys_mlock2 +326 common getcpu_cache sys_getcpu_cache # # x32-specific system call numbers start at 512 to avoid cache impact -- 2.1.4