[PATCH 0/4] x86 entry stuff, maybe for 4.4

From: Andy Lutomirski
Date: Fri Nov 06 2015 - 18:12:56 EST

The first patch is a bit ugly, but it fixes a bug that could affect
lockdep. That bug is very minor and may not be observable at all,
but I don't really want to bet on it.

The other three are intended to fix a performance regression in the
entry rework that FrÃdÃric objected to. They're much later than I'd
like to have sent them for 4.4, but they're kind-of sort-of
regression fixes, so maybe they're still okay. They would certainly
need careful review, though.

I don't have a great benchmark for them. The biggest impact is
likely to be to user page fault latency on CONFIG_CONTEXT_TRACKING=y
kernels (i.e. distro kernels) that don't use context tracking
(i.e. most users).

Andy Lutomirski (4):
x86/entry/64: Fix irqflag tracing wrt context tracking
context_tracking: Switch to new static_branch API
x86/asm: Add asm macros for static keys/jump labels
x86/entry/64: Bypass enter_from_user_mode on non-context-tracking

arch/x86/entry/calling.h | 15 ++++++++++
arch/x86/entry/entry_64.S | 19 ++++++++-----
arch/x86/include/asm/jump_label.h | 52 ++++++++++++++++++++++++++++------
include/linux/context_tracking_state.h | 4 +--
kernel/context_tracking.c | 4 +--
5 files changed, 75 insertions(+), 19 deletions(-)


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