From: "H. Peter Anvin" <hpa@zytor.com>
To: Brian Gerst <brgerst@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>,
x86@kernel.org, torvalds@linux-foundation.org, jeremy@goop.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/6] x86, 32-bit: Add new pt_regs stubs
Date: Wed, 09 Dec 2009 16:05:28 -0800 [thread overview]
Message-ID: <4B203B48.3070906@zytor.com> (raw)
In-Reply-To: <1260403316-5679-2-git-send-email-brgerst@gmail.com>
On 12/09/2009 04:01 PM, Brian Gerst wrote:
> Add new stubs which add the pt_regs pointer as the last arg, matching
> 64-bit. This will allow these syscalls to be easily merged.
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>
> +ptregs_##name: \
> + leal 4(%esp),%edx; \
> + movl PT_EBX(%edx),%eax; \
> + jmp sys_##name;
You're introducing a completely unnecessary pipeline serialization here.
Instead do:
movl (PT_EBX+4)(%esp),%eax;
... making the statements independent and therefore executable in parallel.
-hpa
next prev parent reply other threads:[~2009-12-10 0:07 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-10 0:01 [PATCH 0/6] x86: Merge pt_regs using syscalls Brian Gerst
2009-12-10 0:01 ` [PATCH 1/6] x86, 32-bit: Add new pt_regs stubs Brian Gerst
2009-12-10 0:05 ` H. Peter Anvin [this message]
2009-12-10 0:45 ` [tip:x86/asm] x86-32: " tip-bot for Brian Gerst
2009-12-10 0:47 ` [tip:x86/asm] x86-32: Avoid pipeline serialization in PTREGSCALL1 and 2 tip-bot for H. Peter Anvin
2009-12-10 0:01 ` [PATCH 2/6] x86: Merge sys_iopl Brian Gerst
2009-12-10 0:45 ` [tip:x86/asm] " tip-bot for Brian Gerst
2009-12-10 0:57 ` [tip:x86/asm] x86-64, paravirt: Call set_iopl_mask() on 64 bits tip-bot for H. Peter Anvin
2009-12-10 0:01 ` [PATCH 3/6] x86: Merge sys_execve Brian Gerst
2009-12-10 0:46 ` [tip:x86/asm] " tip-bot for Brian Gerst
2009-12-10 0:01 ` [PATCH 4/6] x86: Merge sys_sigaltstack Brian Gerst
2009-12-10 0:46 ` [tip:x86/asm] " tip-bot for Brian Gerst
2009-12-10 0:01 ` [PATCH 5/6] x86, 32-bit: Convert sys_vm86 & sys_vm86old Brian Gerst
2009-12-10 0:46 ` [tip:x86/asm] " tip-bot for Brian Gerst
2009-12-10 0:01 ` [PATCH 6/6] x86: Merge sys_clone Brian Gerst
2009-12-10 0:46 ` [tip:x86/asm] " tip-bot for Brian Gerst
2009-12-10 0:47 ` [PATCH 0/6] x86: Merge pt_regs using syscalls H. Peter Anvin
2009-12-10 0:52 ` Jeremy Fitzhardinge
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