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Date: Fri, 10 Apr 2015 23:44:21 +0200
From: Borislav Petkov <bp@alien8.de>
To: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Jason Low <jason.low2@hp.com>, Peter Zijlstra <peterz@infradead.org>,
        Davidlohr Bueso <dave@stgolabs.net>,
        Tim Chen <tim.c.chen@linux.intel.com>,
        Aswin Chandramouleeswaran <aswin@hp.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Andy Lutomirski <luto@amacapital.net>, Brian Gerst <brgerst@gmail.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Thomas Gleixner <tglx@linutronix.de>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [PATCH] x86: Align jump targets to 1 byte boundaries
Message-ID: <20150410214421.GP28074@pd.tnic>
References: <20150410111427.GA30477@gmail.com>
 <20150410112748.GB30477@gmail.com>
 <20150410120846.GA17101@gmail.com>
 <20150410131929.GE28074@pd.tnic>
 <5527D631.4090905@redhat.com>
 <20150410140141.GI28074@pd.tnic>
 <5527E3E9.7010608@redhat.com>
 <20150410152510.GK28074@pd.tnic>
 <5527F0E3.40306@redhat.com>
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On Fri, Apr 10, 2015 at 05:54:10PM +0200, Borislav Petkov wrote:
> On Fri, Apr 10, 2015 at 05:48:51PM +0200, Denys Vlasenko wrote:
> > As you know, manuals are not be-all, end-all documents.
> > They contains mistakes. And they are written before silicon
> > is finalized, and sometimes they advertise capabilities
> > which in the end had to be downscaled. It's hard to check
> > a 1000+ pages document and correct all mistakes, especially
> > hard-to-quantify ones.
> > 
> > In the same document by Agner Fog, he says that he failed to confirm
> > 32-byte fetch on Fam16h CPUs:

So reportedly, the fetch window is 32-byte wide but I think there are
restrictions in the pipe elsewhere, which would have negative influence
on the actual throughput. And which could explain Agner's observations.
AFAICT.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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