Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756773AbXLKRGh (ORCPT ); Tue, 11 Dec 2007 12:06:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754474AbXLKRGQ (ORCPT ); Tue, 11 Dec 2007 12:06:16 -0500 Received: from smtpq1.tilbu1.nb.home.nl ([213.51.146.200]:51658 "EHLO smtpq1.tilbu1.nb.home.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752658AbXLKRGN (ORCPT ); Tue, 11 Dec 2007 12:06:13 -0500 Message-ID: <475EC320.5080008@keyaccess.nl> Date: Tue, 11 Dec 2007 18:04:32 +0100 From: Rene Herman User-Agent: Thunderbird 2.0.0.9 (X11/20071031) MIME-Version: 1.0 To: "David P. Reed" CC: Andi Kleen , "linux-os (Dick Johnson)" , David Newall , Paul Rolland , "H. Peter Anvin" , Krzysztof Halasa , Pavel Machek , Alan Cox , linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , rol@witbe.net Subject: Re: RFC: outb 0x80 in inb_p, outb_p harmful on some modern AMD64 with MCP51 laptops References: <475DE37F.20706@davidnewall.com> <475DE6F4.80702@zytor.com> <475DEB23.1000304@davidnewall.com> <20071211084059.3d03e11d@tux.DEF.witbe.net> <475E5D4B.8020101@keyaccess.nl> <475E7DC2.4060509@davidnewall.com> <475E8D91.20201@keyaccess.nl> <475E95A3.3070801@davidnewall.com> <20071211163017.GD16750@one.firstfloor.org> <475EBFBA.6090301@keyaccess.nl> <475EC246.10205@reed.com> In-Reply-To: <475EC246.10205@reed.com> Content-Type: multipart/mixed; boundary="------------070402090502090105000307" X-Spam-Score: -1.0 (-) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2755 Lines: 125 This is a multi-part message in MIME format. --------------070402090502090105000307 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit On 11-12-07 18:00, David P. Reed wrote: > Which port do you want me to test? Oh, thought your previous reply was already responding to this. The "other diagnostic port", 0xed. The point is not so much that it's going to be a good alternate solution but to exclude it being a possible solution. > Also, I can run the timing test on my machine if you share the source > code so I can build it. Thanks, would be interesting. This one: Rene. --------------070402090502090105000307 Content-Type: text/plain; name="port80.c" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="port80.c" #include #include #include #define LOOPS 1000 unsigned long cycles[LOOPS]; int main(void) { unsigned long overhead; unsigned long total; int i; if (iopl(3) < 0) { perror("iopl"); return EXIT_FAILURE; } /* pull it in */ for (i = 0; i < LOOPS; i++) cycles[i] = 0; asm volatile ("cli"); for (i = 0; i < LOOPS; i++) asm ( "xor %%eax, %%eax \n\t" "cpuid \n\t" "rdtsc \n\t" "movl %%eax, %%esi \n\t" "xor %%eax, %%eax \n\t" "cpuid \n\t" "rdtsc \n\t" "subl %%esi, %%eax \n\t" : "=a" (cycles[i]) : : "ecx", "edx", "ebx", "esi"); asm volatile ("sti"); overhead = 0; for (i = 0; i < LOOPS; i++) overhead += cycles[i]; asm volatile ("cli"); for (i = 0; i < LOOPS; i++) asm ( "xor %%eax, %%eax \n\t" "cpuid \n\t" "rdtsc \n\t" "movl %%eax, %%esi \n\t" "outb %%al, $0x80 \n\t" "xor %%eax, %%eax \n\t" "cpuid \n\t" "rdtsc \n\t" "subl %%esi, %%eax \n\t" : "=a" (cycles[i]) : : "ecx", "edx", "ebx", "esi"); asm volatile ("sti"); total = 0; for (i = 0; i < LOOPS; i++) total += cycles[i]; total -= overhead; printf("out: %lu\n", total / LOOPS); asm volatile ("cli"); for (i = 0; i < LOOPS; i++) asm ( "xor %%eax, %%eax \n\t" "cpuid \n\t" "rdtsc \n\t" "movl %%eax, %%esi \n\t" "inb $0x80, %%al \n\t" "xor %%eax, %%eax \n\t" "cpuid \n\t" "rdtsc \n\t" "subl %%esi, %%eax \n\t" : "=a" (cycles[i]) : : "ecx", "edx", "ebx", "esi"); asm volatile ("sti"); total = 0; for (i = 0; i < LOOPS; i++) total += cycles[i]; total -= overhead; printf("in : %lu\n", total / LOOPS); return EXIT_SUCCESS; } --------------070402090502090105000307-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/