From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: mingo@kernel.org, tglx@linutronix.de, hpa@zytor.com,
linux-kernel@vger.kernel.org, torvalds@linux-foundation.org,
arjan@linux.intel.com, bp@alien8.de,
richard.weinberger@gmail.com
Subject: Re: [PATCH 1/5] x86: Implement __WARN using UD0
Date: Wed, 22 Mar 2017 09:18:23 -0500 [thread overview]
Message-ID: <20170322141823.2ilzsmfeghe3ra4j@treble> (raw)
In-Reply-To: <20170322084706.GV5680@worktop>
On Wed, Mar 22, 2017 at 09:47:06AM +0100, Peter Zijlstra wrote:
>
> A little like so then.
>
> ---
> Subject: x86: Implement __WARN using UD0
> From: Peter Zijlstra <peterz@infradead.org>
> Date: Thu Feb 2 14:43:51 CET 2017
>
> By using "UD0" for WARNs we remove the function call and its possible
> __FILE__ and __LINE__ immediate arguments from the instruction stream.
>
> Total image size will not change much, what we win in the instruction
> stream we'll loose because of the __bug_table entries. Still, saves on
> I$ footprint and the total image size does go down a bit.
>
> text data bss dec hex filename
> 10702123 4530992 843776 16076891 f5505b defconfig-build/vmlinux.0
> 10682460 4530992 843776 16057228 f5038c defconfig-build/vmlinux.1
>
> (um didn't seem to use GENERIC_BUG at all, so remove it)
>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Richard Weinberger <richard.weinberger@gmail.com>
> Cc: Arjan van de Ven <arjan@linux.intel.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Josh Poimboeuf <jpoimboe@redhat.com>
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Looks good, thanks!
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
--
Josh
next prev parent reply other threads:[~2017-03-22 14:18 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-17 21:19 [PATCH 0/5] x86 optimizations Peter Zijlstra
2017-03-17 21:19 ` [PATCH 1/5] x86: Implement __WARN using UD0 Peter Zijlstra
2017-03-21 14:03 ` Josh Poimboeuf
2017-03-21 15:14 ` Peter Zijlstra
2017-03-21 15:17 ` Arjan van de Ven
2017-03-21 15:32 ` Josh Poimboeuf
2017-03-21 15:41 ` Peter Zijlstra
2017-03-22 8:47 ` Peter Zijlstra
2017-03-22 14:18 ` Josh Poimboeuf [this message]
2017-03-17 21:19 ` [PATCH 2/5] bug: Add _ONCE logic to report_bug() Peter Zijlstra
2017-03-17 21:19 ` [PATCH 3/5] atomic: Introduce atomic_try_cmpxchg() Peter Zijlstra
2017-03-17 21:19 ` [PATCH 4/5] refcount: Use atomic_try_cmpxchg() Peter Zijlstra
2017-03-17 21:19 ` [PATCH 5/5] x86,atomic: Use atomic_try_cmpxchg Peter Zijlstra
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