From: Peter Zijlstra <peterz@infradead.org>
To: Nadav Amit <namit@vmware.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [PATCH v3 4/9] x86: alternatives: macrofy locks for better inlining
Date: Mon, 11 Jun 2018 10:03:14 +0200 [thread overview]
Message-ID: <20180611080314.GR12258@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20180610141911.52948-5-namit@vmware.com>
On Sun, Jun 10, 2018 at 07:19:06AM -0700, Nadav Amit wrote:
> #ifdef CONFIG_SMP
> +.macro LOCK_PREFIX_HERE
> .pushsection .smp_locks,"a"
> .balign 4
> + .long 671f - . # offset
> .popsection
> +671:
> +.endm
> +
> +.macro LOCK_PREFIX insn:vararg
> + LOCK_PREFIX_HERE
> + lock \insn
> +.endm
Hurmph, the only reason we need to preserve that LOCK_PREFIX_HERE thing
is arch_cmpxchg64 in cmpxchg_32.h. Is there really no other way we can
write that one?
I suppose the problem with using LOCK_PREFIX inside the alternative is
that the .smp_locks fixup address gets computed wrong (inside the
alternative_text section instead of in the regular text)?
Oh well..
next prev parent reply other threads:[~2018-06-11 8:03 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-10 14:19 [PATCH v3 0/9] x86: macrofying inline asm for better compilation Nadav Amit
2018-06-10 14:19 ` Nadav Amit
2018-06-10 14:19 ` [PATCH v3 1/9] Makefile: Prepare for using macros for inline asm Nadav Amit
2018-06-10 14:19 ` Nadav Amit
2018-06-10 14:19 ` [PATCH v3 2/9] x86: objtool: use asm macro for better compiler decisions Nadav Amit
2018-06-10 14:19 ` Nadav Amit
2018-06-10 14:19 ` [PATCH v3 3/9] x86: refcount: prevent gcc distortions Nadav Amit
2018-06-10 14:19 ` [PATCH v3 4/9] x86: alternatives: macrofy locks for better inlining Nadav Amit
2018-06-11 8:03 ` Peter Zijlstra [this message]
2018-06-10 14:19 ` [PATCH v3 5/9] x86: bug: prevent gcc distortions Nadav Amit
2018-06-10 14:19 ` [PATCH v3 6/9] x86: prevent inline distortion by paravirt ops Nadav Amit
2018-06-11 7:45 ` Peter Zijlstra
2018-06-11 7:45 ` Peter Zijlstra
2018-06-12 3:49 ` Nadav Amit
2018-06-10 14:19 ` [PATCH v3 7/9] x86: extable: use macros instead of inline assembly Nadav Amit
2018-06-10 14:19 ` [PATCH v3 8/9] x86: cpufeature: " Nadav Amit
2018-06-10 14:19 ` [PATCH v3 9/9] x86: jump-labels: " Nadav Amit
2018-06-11 1:29 ` hpa
2018-06-11 3:47 ` Nadav Amit
2018-06-11 7:50 ` Peter Zijlstra
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