x86_64, entry: Remove the syscall exit audit and schedule optimizations
authorAndy Lutomirski <luto@amacapital.net>
Mon, 7 Jul 2014 18:37:17 +0000 (11:37 -0700)
committerAndy Lutomirski <luto@amacapital.net>
Sun, 1 Feb 2015 12:03:02 +0000 (04:03 -0800)
commit96b6352c12711d5c0bb7157f49c92580248e8146
tree66414331ab05782fbecaf68aeb081cc8ea7d1c29
parent2a23c6b8a9c42620182a2d2cfc7c16f6ff8c42b4
x86_64, entry: Remove the syscall exit audit and schedule optimizations

We used to optimize rescheduling and audit on syscall exit.  Now
that the full slow path is reasonably fast, remove these
optimizations.  Syscall exit auditing is now handled exclusively by
syscall_trace_leave.

This adds something like 10ns to the previously optimized paths on
my computer, presumably due mostly to SAVE_REST / RESTORE_REST.

I think that we should eventually replace both the syscall and
non-paranoid interrupt exit slow paths with a pair of C functions
along the lines of the syscall entry hooks.

Link: http://lkml.kernel.org/r/22f2aa4a0361707a5cfb1de9d45260b39965dead.1421453410.git.luto@amacapital.net
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
arch/x86/kernel/entry_64.S