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 <[email protected]> CC: Russell King <[email protected]> CC: Catalin Marinas <[email protected]> CC: Will Deacon <[email protected]> CC: Thomas Gleixner <[email protected]> CC: Paul Turner <[email protected]> CC: Andrew Hunter <[email protected]> CC: Peter Zijlstra <[email protected]> CC: Andy Lutomirski <[email protected]> CC: Andi Kleen <[email protected]> CC: Dave Watson <[email protected]> CC: Chris Lameter <[email protected]> CC: Ingo Molnar <[email protected]> CC: Ben Maurer <[email protected]> CC: Steven Rostedt <[email protected]> CC: "Paul E. McKenney" <[email protected]> CC: Josh Triplett <[email protected]> CC: Linus Torvalds <[email protected]> CC: Andrew Morton <[email protected]> CC: Thomas Gleixner <[email protected]> CC: [email protected] --- 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 a89fdbc..f7e6e12 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 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
