Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758762AbXI0WSA (ORCPT ); Thu, 27 Sep 2007 18:18:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758664AbXI0WRu (ORCPT ); Thu, 27 Sep 2007 18:17:50 -0400 Received: from terminus.zytor.com ([198.137.202.10]:39080 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758497AbXI0WRt (ORCPT ); Thu, 27 Sep 2007 18:17:49 -0400 Message-ID: <46FC2BFD.6070200@zytor.com> Date: Thu, 27 Sep 2007 15:17:33 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.0 (X11/20070419) MIME-Version: 1.0 To: jkeating@redhat.com, Joerg Pommnitz , Jordan Crouse , Chuck Ebbert CC: Linux Kernel Mailing List , Andi Kleen Subject: More E820 brokenness X-Enigmail-Version: 0.95.0 Content-Type: multipart/mixed; boundary="------------050404080908040209060500" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2497 Lines: 53 This is a multi-part message in MIME format. --------------050404080908040209060500 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit As luck would have it, it's not just an obscure Geode system which has a broken E820 implementation. Today I received a bug report about a Dell system (XPS M1330) with broken E820. Unfortunately, the workaround for the Geode breaks this system, because x86-64 doesn't fall back to the e801/88 information like the i386 kernel does. I wonder if the relevant people could test out this patch to see how it works on their respective system. This patch reverts to 2.6.23-rc8 behaviour of simply truncating the map, but still makes e801/88 info available to the kernel; this hopefully should match 2.6.22 behaviour. I want to emphasize that this is seriously broken. Using a partial e820 map could have disastrous results, since the kernel will have partial memory map information and not know about reserved areas, etc. Part of me feels that the right thing to do is what the current git kernel does -- either fall back to e801, or stop and error. (Andi: I would particularly appreciate your opinion on this issue.) -hpa --------------050404080908040209060500 Content-Type: text/plain; name="diff" Content-Transfer-Encoding: base64 Content-Disposition: inline; filename="diff" ZGlmZiAtLWdpdCBhL2FyY2gvaTM4Ni9ib290L21lbW9yeS5jIGIvYXJjaC9pMzg2L2Jvb3Qv bWVtb3J5LmMKaW5kZXggYmNjYWExYy4uODQ5MzliNyAxMDA2NDQKLS0tIGEvYXJjaC9pMzg2 L2Jvb3QvbWVtb3J5LmMKKysrIGIvYXJjaC9pMzg2L2Jvb3QvbWVtb3J5LmMKQEAgLTM0LDE3 ICszNCw3IEBAIHN0YXRpYyBpbnQgZGV0ZWN0X21lbW9yeV9lODIwKHZvaWQpCiAJCSAgICAg ICI9bSIgKCpkZXNjKQogCQkgICAgOiAiRCIgKGRlc2MpLCAiYSIgKDB4ZTgyMCkpOwogCi0J CS8qIFNvbWUgQklPU2VzIHN0b3AgcmV0dXJuaW5nIFNNQVAgaW4gdGhlIG1pZGRsZSBvZgot CQkgICB0aGUgc2VhcmNoIGxvb3AuICBXZSBkb24ndCBrbm93IGV4YWN0bHkgaG93IHRoZSBC SU9TCi0JCSAgIHNjcmV3ZWQgdXAgdGhlIG1hcCBhdCB0aGF0IHBvaW50LCB3ZSBtaWdodCBo YXZlIGEKLQkJICAgcGFydGlhbCBtYXAsIHRoZSBmdWxsIG1hcCwgb3IgY29tcGxldGUgZ2Fy YmFnZSwgc28KLQkJICAganVzdCByZXR1cm4gZmFpbHVyZS4gKi8KLQkJaWYgKGlkICE9IFNN QVApIHsKLQkJCWNvdW50ID0gMDsKLQkJCWJyZWFrOwotCQl9Ci0KLQkJaWYgKGVycikKKwkJ aWYgKGlkICE9IFNNQVAgfHwgZXJyKQogCQkJYnJlYWs7CiAKIAkJY291bnQrKzsK --------------050404080908040209060500-- - 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/