x86/entry: Remove _TIF_NOHZ from _TIF_WORK_SYSCALL_ENTRY

Evaluating _TIF_NOHZ to decide whether to use the slow syscall entry path
is not only pointless, it's actually counterproductive:

 1) Context tracking code is invoked unconditionally before that flag is
    evaluated.

 2) If the flag is set the slow path is invoked for nothing due to #1

Remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>

diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index cf43279..6cb9d1b 100644 (file)
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -133,14 +133,10 @@ struct thread_info {
 #define _TIF_X32               (1 << TIF_X32)
 #define _TIF_FSCHECK           (1 << TIF_FSCHECK)
 
-/*
- * work to do in syscall_trace_enter().  Also includes TIF_NOHZ for
- * enter_from_user_mode()
- */
+/* Work to do before invoking the actual syscall. */
 #define _TIF_WORK_SYSCALL_ENTRY        \
        (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT |   \
-        _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT |       \
-        _TIF_NOHZ)
+        _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT)
 
 /* flags to check in __switch_to() */
 #define _TIF_WORK_CTXSW_BASE                                   \