Wire up the getcpu cache system call on 32-bit ARM. 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 ARM by skipping the getcpu system call on the fast path.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
CC: Russell King <li...@arm.linux.org.uk>
CC: Catalin Marinas <catalin.mari...@arm.com>
CC: Will Deacon <will.dea...@arm.com>
CC: Thomas Gleixner <t...@linutronix.de>
CC: Paul Turner <p...@google.com>
CC: Andrew Hunter <a...@google.com>
CC: Peter Zijlstra <pet...@infradead.org>
CC: Andy Lutomirski <l...@amacapital.net>
CC: Andi Kleen <a...@firstfloor.org>
CC: Dave Watson <davejwat...@fb.com>
CC: Chris Lameter <c...@linux.com>
CC: Ingo Molnar <mi...@redhat.com>
CC: Ben Maurer <bmau...@fb.com>
CC: Steven Rostedt <rost...@goodmis.org>
CC: "Paul E. McKenney" <paul...@linux.vnet.ibm.com>
CC: Josh Triplett <j...@joshtriplett.org>
CC: Linus Torvalds <torva...@linux-foundation.org>
CC: Andrew Morton <a...@linux-foundation.org>
CC: Thomas Gleixner <t...@linutronix.de>
CC: linux-...@vger.kernel.org
---
arch/arm/include/uapi/asm/unistd.h | 1 +
arch/arm/kernel/calls.S | 1 +
arch/arm/kernel/signal.c | 1 +
3 files changed, 3 insertions(+)
diff --git a/arch/arm/include/uapi/asm/unistd.h
b/arch/arm/include/uapi/asm/unistd.h
index 7a2a32a..6605e94 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_getcpu_cache (__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..6786411 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_getcpu_cache)
#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..ff5052c 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -594,6 +594,7 @@ do_work_pending(struct pt_regs *regs, unsigned int
thread_flags, int syscall)
} else {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
+ getcpu_cache_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 majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
