Message-ID: <1040323590.3e0214063a990@209.51.155.18>
Date: Thu, 19 Dec 2002 13:46:30 -0500
From: billyrose@billyrose.net
To: bart@etpmod.phys.tue.nl
Cc: root@chaos.analogic.com, linux-kernel@vger.kernel.org
Subject: Re: Intel P6 vs P7 system call performance
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> Not true. A ret(urn) is (sort of) equivalent to 'pop %eip'. The above
> code would actually jump to address 0xfffff000, but probably be slow
> since it confuses the branch prediction.
>
>
>Bart

that being the case, then the original code that Linus put forth:

        pushl $0xfffff000
        call *(%esp)
        add $4,%esp

would be the way to go as it is highly readable. actually, the code at
0xfffff000 could issue a ret $4 and eliminate the add after the call.

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