From: Thomas Gleixner <tglx@linutronix.de>
To: Andy Lutomirski <luto@kernel.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
"Brian Gerst" <brgerst@gmail.com>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Borislav Petkov" <bp@alien8.de>,
"Frédéric Weisbecker" <fweisbec@gmail.com>,
"Peter Zijlstra" <peterz@infradead.org>
Subject: Re: [PATCH v3 5/5] x86/entry/64: Bypass enter_from_user_mode on non-context-tracking boots
Date: Fri, 13 Nov 2015 09:23:25 -0500 (EST) [thread overview]
Message-ID: <alpine.DEB.2.11.1511130923090.3903@nanos> (raw)
In-Reply-To: <73ee804fff48cd8c66b65b724f9f728a11a8c686.1447361906.git.luto@kernel.org>
On Thu, 12 Nov 2015, Andy Lutomirski wrote:
> On CONFIG_CONTEXT_TRACKING kernels that have context tracking
> disabled at runtime (which includes most distro kernels), we still
> have the overhead of a call to enter_from_user_mode in interrupt and
> exception entries.
>
> If jump labels are available, this uses the jump label
> infrastructure to skip the call.
>
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
next prev parent reply other threads:[~2015-11-13 14:24 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-12 20:58 [PATCH v3 0/5] x86 entry stuff, maybe for 4.4 Andy Lutomirski
2015-11-12 20:59 ` [PATCH v3 1/5] x86/entry/64: Fix irqflag tracing wrt context tracking Andy Lutomirski
2015-11-24 9:35 ` [tip:x86/asm] " tip-bot for Andy Lutomirski
2015-11-12 20:59 ` [PATCH v3 2/5] context_tracking: Switch to new static_branch API Andy Lutomirski
2015-11-24 9:35 ` [tip:x86/asm] " tip-bot for Andy Lutomirski
2015-11-12 20:59 ` [PATCH v3 3/5] x86/asm: Error out if asm/jump_label.h is included inappropriately Andy Lutomirski
2015-11-13 14:13 ` Thomas Gleixner
2015-11-24 9:35 ` [tip:x86/asm] x86/asm: Error out if asm/ jump_label.h " tip-bot for Andy Lutomirski
2015-11-12 20:59 ` [PATCH v3 4/5] x86/asm: Add asm macros for static keys/jump labels Andy Lutomirski
2015-11-13 14:22 ` Thomas Gleixner
2015-11-24 9:36 ` [tip:x86/asm] " tip-bot for Andy Lutomirski
2015-11-12 20:59 ` [PATCH v3 5/5] x86/entry/64: Bypass enter_from_user_mode on non-context-tracking boots Andy Lutomirski
2015-11-13 14:23 ` Thomas Gleixner [this message]
2015-11-13 15:26 ` Frederic Weisbecker
2015-11-16 19:10 ` Andy Lutomirski
2015-11-16 22:50 ` Frederic Weisbecker
2015-11-16 23:57 ` Andy Lutomirski
2015-11-19 0:57 ` Frederic Weisbecker
2015-11-24 9:36 ` [tip:x86/asm] " tip-bot for Andy Lutomirski
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