Bug#720272: unbootable and lead to data loss?
Today I tried -686-pae on my model name : Intel(R) Celeron(R) M processor 1.40GHz flags : fpu vme de pse tsc msr mce cx8 sep mtrr pge mca cmov clflush dts acpi mmx fxsr sse sse2 ss tm pbe bts and it booted fine...despite all expert opinion I got years ago. That's why an official script is needed to give the correct answer. -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/87mwo84qyh@jidanni.org
Bug#720272: unbootable and lead to data loss?
So could you guys make a script with three possible answers: $ ./check-if-my-machine-should-use-686-pae-or-486 Congratulations, you can use the 686-pae kernel! Sorry, you must use the 486 kernel! Maybe: It is hard to say, all we can say is try it. It will either boot or not, and you will know right away. I mean how can this all be so hard to determine algorithmcally? -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/87haehm7gd@jidanni.org
Bug#720272: unbootable and lead to data loss?
And fourth possibility, Your system probably can use 686-pae, but is not officially approved to do so by your manufacture. Therefore we must ask you not to use it. -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/878uztm4u6@jidanni.org
Bug#720272: unbootable and lead to data loss?
On Tue, 2013-08-20 at 22:51 +0800, jida...@jidanni.org wrote: What will happen if I boot product: Intel(R) Celeron(R) M processor 1.40GHz version: 6.13.6 size: 1400MHz capacity: 1400MHz width: 32 bits clock: 400MHz capabilities: fpu fpu_exception wp vme de pse tsc msr mce cx8 sep mtrr pge mca cmov clflush dts acpi mmx fxsr sse sse2 ss tm pbe up bts with -686-pae? Will it not boot at all? Will it run normally but with subtle data corruption to my files? The kernel will always either boot or not boot (with a message from the very early loader about lack of PAE). On the system above it looks like it wouldn't boot due to lack of PAE. It will definitely not boot and the lead to subtle corruption of data or anything like that. Ian. -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/1377072014.31198.11.ca...@dagon.hellion.org.uk
Bug#720272: unbootable and lead to data loss?
On Wed, Aug 21, 2013 at 09:00:14AM +0100, Ian Campbell wrote: On Tue, 2013-08-20 at 22:51 +0800, jida...@jidanni.org wrote: product: Intel(R) Celeron(R) M processor 1.40GHz capabilities: fpu fpu_exception wp vme de pse tsc msr mce cx8 sep mtrr pge mca cmov clflush dts acpi mmx fxsr sse sse2 ss tm pbe up bts The kernel will always either boot or not boot (with a message from the very early loader about lack of PAE). On the system above it looks like it wouldn't boot due to lack of PAE. It is quite possible that this CPU actually supports PAE. They don't show it until you try to enable it. Bastian -- Where there's no emotion, there's no motive for violence. -- Spock, Dagger of the Mind, stardate 2715.1 -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20130821093003.ga15...@mail.waldi.eu.org
Bug#720272: unbootable and lead to data loss?
On Wed, 2013-08-21 at 11:30 +0200, Bastian Blank wrote: On Wed, Aug 21, 2013 at 09:00:14AM +0100, Ian Campbell wrote: On Tue, 2013-08-20 at 22:51 +0800, jida...@jidanni.org wrote: product: Intel(R) Celeron(R) M processor 1.40GHz capabilities: fpu fpu_exception wp vme de pse tsc msr mce cx8 sep mtrr pge mca cmov clflush dts acpi mmx fxsr sse sse2 ss tm pbe up bts The kernel will always either boot or not boot (with a message from the very early loader about lack of PAE). On the system above it looks like it wouldn't boot due to lack of PAE. It is quite possible that this CPU actually supports PAE. They don't show it until you try to enable it. Ah, I wasn't sure if the kernel would check for the CPUID bit and just fail or do something more clever to see if it worked. In any case my main point is that it will either work or not. There is no half working/data corrupting case. Ian. -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/1377078799.31937.34.ca...@hastur.hellion.org.uk
Bug#720272: unbootable and lead to data loss?
On Wed, 2013-08-21 at 10:53 +0100, Ian Campbell wrote: On Wed, 2013-08-21 at 11:30 +0200, Bastian Blank wrote: On Wed, Aug 21, 2013 at 09:00:14AM +0100, Ian Campbell wrote: On Tue, 2013-08-20 at 22:51 +0800, jida...@jidanni.org wrote: product: Intel(R) Celeron(R) M processor 1.40GHz capabilities: fpu fpu_exception wp vme de pse tsc msr mce cx8 sep mtrr pge mca cmov clflush dts acpi mmx fxsr sse sse2 ss tm pbe up bts The kernel will always either boot or not boot (with a message from the very early loader about lack of PAE). On the system above it looks like it wouldn't boot due to lack of PAE. It is quite possible that this CPU actually supports PAE. They don't show it until you try to enable it. Ah, I wasn't sure if the kernel would check for the CPUID bit and just fail or do something more clever to see if it worked. In any case my main point is that it will either work or not. There is no half working/data corrupting case. There might be if the CPUs that don't advertise PAE also weren't tested for PAE functionality at manufacturing time. But if we make the 686-pae kernel refuse to boot without PAE advertised, we'll also break currently working systems. Ben. -- Ben Hutchings The obvious mathematical breakthrough [to break modern encryption] would be development of an easy way to factor large prime numbers. - Bill Gates signature.asc Description: This is a digitally signed message part
Bug#720272: unbootable and lead to data loss?
On Wed, 2013-08-21 at 11:11 +0100, Ben Hutchings wrote: On Wed, 2013-08-21 at 10:53 +0100, Ian Campbell wrote: On Wed, 2013-08-21 at 11:30 +0200, Bastian Blank wrote: On Wed, Aug 21, 2013 at 09:00:14AM +0100, Ian Campbell wrote: On Tue, 2013-08-20 at 22:51 +0800, jida...@jidanni.org wrote: product: Intel(R) Celeron(R) M processor 1.40GHz capabilities: fpu fpu_exception wp vme de pse tsc msr mce cx8 sep mtrr pge mca cmov clflush dts acpi mmx fxsr sse sse2 ss tm pbe up bts The kernel will always either boot or not boot (with a message from the very early loader about lack of PAE). On the system above it looks like it wouldn't boot due to lack of PAE. It is quite possible that this CPU actually supports PAE. They don't show it until you try to enable it. Ah, I wasn't sure if the kernel would check for the CPUID bit and just fail or do something more clever to see if it worked. In any case my main point is that it will either work or not. There is no half working/data corrupting case. There might be if the CPUs that don't advertise PAE also weren't tested for PAE functionality at manufacturing time. Hrm, that's true I guess. I'm a bit surprised that the upstream guys just enable PAE blindy on systems which don't advertise it TBH, that's not very conservative, I could better imagine them whitelisting some machines which were known good. Looking at the kernel though, if CONFIG_X86_PAE is set then NEED_PAE is set, this is then included in REQUIRED_MASK0. If I'm reading it right then arch/x86/boot/cpucheck.c seems to want to require these bits to be set and it will eventually crap out in validate_cpu. I don't actually have a non-pae system to try this on though... But if we make the 686-pae kernel refuse to boot without PAE advertised, we'll also break currently working systems. Ian. -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/1377081028.31937.60.ca...@hastur.hellion.org.uk
Bug#720272: unbootable and lead to data loss?
On Wed, Aug 21, 2013 at 11:11:21AM +0100, Ben Hutchings wrote: There might be if the CPUs that don't advertise PAE also weren't tested for PAE functionality at manufacturing time. Does the spec for this cpu family mandate the check in CPUID? Well I checked and it tells: | Software can discover support for different paging features using the | CPUID instruction: | PAE: physical-address extension. | If CPUID.01H:EDX.PAE [bit 6] = 1, CR4.PAE may be set to 1, enabling PAE | paging (this setting is also required for IA-32e paging). So it is not mandatory. Other parts are more specific, for example: | (Processors that do not support CPUID function 8001H do not allow | IA32_EFER.NXE to be set to 1.) Bastian -- Vulcans never bluff. -- Spock, The Doomsday Machine, stardate 4202.1 -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/2013082120.gb15...@mail.waldi.eu.org
Bug#720272: unbootable and lead to data loss?
On Tue, Aug 20, 2013 at 07:53:06AM +0800, jida...@jidanni.org wrote: Thus wouldn't installing it and removing other kernels make the system unbootable or lead to data loss? No. First: no kernel is removed automatically. Second: The data loss definition only applies to automatic stuff, not to something the user does. Bastian -- You! What PLANET is this! -- McCoy, The City on the Edge of Forever, stardate 3134.0 -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20130820063508.gb9...@mail.waldi.eu.org
Bug#720272: unbootable and lead to data loss?
What will happen if I boot product: Intel(R) Celeron(R) M processor 1.40GHz version: 6.13.6 size: 1400MHz capacity: 1400MHz width: 32 bits clock: 400MHz capabilities: fpu fpu_exception wp vme de pse tsc msr mce cx8 sep mtrr pge mca cmov clflush dts acpi mmx fxsr sse sse2 ss tm pbe up bts with -686-pae? Will it not boot at all? Will it run normally but with subtle data corruption to my files? Why can't there be a utility checker script (like the autoconf - automatic configure script builder) a user could use to detect such dangers, without needing to ask the experts each time? $ ./is-486-or-686-pae-right-for-me? ...checking cpuinfo ...checking something else Congratulations, your system is suitable for -686-pae !! $ ./is-486-or-686-pae-right-for-me? ...checking cpuinfo ...checking something else Sorry, your system should use the older -486, not the -686-pae!! Such a script could be included with all Debian kernel packages, so curious users could check before filling their /boots with the wrong stuff! No more need to comb newsgroups for answers about things one doesn't understand. Let the expert script answer the mystery! -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/87d2p8wh3x@jidanni.org
Bug#720272: unbootable and lead to data loss?
The Description says: This kernel requires PAE (Physical Address Extension). Thus wouldn't installing it and removing other kernels make the system unbootable or lead to data loss? -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/878uzxw84d@jidanni.org
