Messages in this thread | | | From | Andy Lutomirski <> | Subject | [PATCH 0/4] x86 entry stuff, maybe for 4.4 | Date | Fri, 6 Nov 2015 15:12:42 -0800 |
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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 Frédéric 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 boots
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(-)
-- 2.4.3
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