From: "H. Peter Anvin" <hpa@zytor.com>
To: Borislav Petkov <bp@alien8.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86, cpu: Fix X86_FEATURE_NOPL
Date: Mon, 04 Oct 2010 14:50:35 -0700 [thread overview]
Message-ID: <4CAA4C2B.2050909@zytor.com> (raw)
In-Reply-To: <20101004214838.GA26084@liondog.tnic>
>>
>> Agreed that this should be cleaned up. However, in the meantime I'd
>> like to keep Borislav's patch in the tree since it makes the code
>> technically correct at least.
>
> I think the cleanup should be easy: on 64-bit unconditionally return
> p6_nops in find_nop_table() since every 64-bit processor should support
> them and on 32-bit never return p6_nops since X86_FEATURE_NOPL is not
> set there and fall back to intel_nops on non-AMD. Which means we can get
> rid of X86_FEATURE_NOPL altogether. Too radical?
>
This is fine with me, but you may want to check with your employer if
the Intel NOPs will perform slower than the 66 ... 90 NOPs on AMD
processors.
-hpa
next prev parent reply other threads:[~2010-10-04 21:51 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-03 9:37 NOPL on 32-bit Borislav Petkov
2010-10-03 14:43 ` H. Peter Anvin
2010-10-03 15:22 ` [PATCH] x86, cpu: X86_FEATURE_NOPL should be disabled on 32-bit only Borislav Petkov
2010-10-03 18:19 ` H. Peter Anvin
2010-10-03 20:11 ` Borislav Petkov
2010-10-03 22:22 ` H. Peter Anvin
2010-10-04 7:31 ` [PATCH] x86, cpu: Fix X86_FEATURE_NOPL Borislav Petkov
2010-10-04 20:36 ` [tip:x86/cpu] " tip-bot for Borislav Petkov
2010-10-05 9:47 ` Borislav Petkov
2010-10-05 16:30 ` H. Peter Anvin
2010-10-05 16:53 ` Borislav Petkov
2010-10-04 20:47 ` [PATCH] " Linus Torvalds
2010-10-04 21:02 ` H. Peter Anvin
2010-10-04 21:12 ` Linus Torvalds
2010-10-04 21:21 ` H. Peter Anvin
2010-10-04 21:48 ` Borislav Petkov
2010-10-04 21:50 ` H. Peter Anvin [this message]
2010-10-04 21:53 ` H. Peter Anvin
2010-10-05 6:19 ` Borislav Petkov
2010-10-04 22:17 ` Hugh Dickins
2010-10-04 22:19 ` H. Peter Anvin
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