* Which CPU for VIA C7/Esther? @ 2007-02-12 17:37 Mark de Vries 2007-02-12 19:14 ` Kyle McMartin 0 siblings, 1 reply; 5+ messages in thread From: Mark de Vries @ 2007-02-12 17:37 UTC (permalink / raw) To: linux-kernel Hi, I've been googeling for about an hour now and can't find an answer to: What type of CPU should I select when compiling a recent 2.6 kernel if I have a VIA Esther CPU? Please CC me, I'm not on the list. Thanks & Regards, Mark. ~$ cat /proc/cpuinfo processor : 0 vendor_id : CentaurHauls cpu family : 6 model : 10 model name : VIA Esther processor 1200MHz stepping : 9 cpu MHz : 1200.189 cache size : 128 KB fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 1 wp : yes flags : fpu vme de pse tsc msr pae mce apic sep mtrr pge cmov pat clflush acpi mmx fxsr sse sse2 tm nx up pni est tm2 rng rng_en ace ace_en bogomips : 2407.15 ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Which CPU for VIA C7/Esther? 2007-02-12 17:37 Which CPU for VIA C7/Esther? Mark de Vries @ 2007-02-12 19:14 ` Kyle McMartin 2007-02-12 20:16 ` Dave Jones 0 siblings, 1 reply; 5+ messages in thread From: Kyle McMartin @ 2007-02-12 19:14 UTC (permalink / raw) To: Mark de Vries; +Cc: linux-kernel On Mon, Feb 12, 2007 at 06:37:38PM +0100, Mark de Vries wrote: > I've been googeling for about an hour now and can't find an answer to: > What type of CPU should I select when compiling a recent 2.6 kernel if I > have a VIA Esther CPU? > stepping : 9 config MVIAC3_2 bool "VIA C3-2 (Nehemiah)" help Select this for a VIA C3 "Nehemiah". Selecting this enables usage of SSE and tells gcc to treat the CPU as a 686. Note, this kernel will not boot on older (pre model 9) C3s. Is the one you want, I believe. Cheers, Kyle ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Which CPU for VIA C7/Esther? 2007-02-12 19:14 ` Kyle McMartin @ 2007-02-12 20:16 ` Dave Jones 2007-02-12 23:46 ` Simon Arlott 0 siblings, 1 reply; 5+ messages in thread From: Dave Jones @ 2007-02-12 20:16 UTC (permalink / raw) To: Kyle McMartin; +Cc: Mark de Vries, linux-kernel On Mon, Feb 12, 2007 at 02:14:41PM -0500, Kyle McMartin wrote: > On Mon, Feb 12, 2007 at 06:37:38PM +0100, Mark de Vries wrote: > > I've been googeling for about an hour now and can't find an answer to: > > What type of CPU should I select when compiling a recent 2.6 kernel if I > > have a VIA Esther CPU? > > > stepping : 9 > > config MVIAC3_2 > bool "VIA C3-2 (Nehemiah)" > help > Select this for a VIA C3 "Nehemiah". Selecting this enables usage > of SSE and tells gcc to treat the CPU as a 686. > Note, this kernel will not boot on older (pre model 9) C3s. > > Is the one you want, I believe. The C7 doesn't seem to care much which you optimise it for. Any of the 686 options should work just fine, but MVIAC3_2 is no worse than any of the others. Dave -- http://www.codemonkey.org.uk ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Which CPU for VIA C7/Esther? 2007-02-12 20:16 ` Dave Jones @ 2007-02-12 23:46 ` Simon Arlott 2007-02-12 23:59 ` Dave Jones 0 siblings, 1 reply; 5+ messages in thread From: Simon Arlott @ 2007-02-12 23:46 UTC (permalink / raw) To: Dave Jones, Kyle McMartin, Mark de Vries, linux-kernel [-- Attachment #1: Type: text/plain, Size: 1506 bytes --] On 12/02/07 20:16, Dave Jones wrote: > On Mon, Feb 12, 2007 at 02:14:41PM -0500, Kyle McMartin wrote: > > On Mon, Feb 12, 2007 at 06:37:38PM +0100, Mark de Vries wrote: > > > I've been googeling for about an hour now and can't find an answer to: > > > What type of CPU should I select when compiling a recent 2.6 kernel if I > > > have a VIA Esther CPU? > > > > > stepping : 9 > > > > config MVIAC3_2 > > bool "VIA C3-2 (Nehemiah)" > > help > > Select this for a VIA C3 "Nehemiah". Selecting this enables usage > > of SSE and tells gcc to treat the CPU as a 686. > > Note, this kernel will not boot on older (pre model 9) C3s. > > > > Is the one you want, I believe. > > The C7 doesn't seem to care much which you optimise it for. > Any of the 686 options should work just fine, but MVIAC3_2 is no > worse than any of the others. > MVIAC3_2 doesn't enable X86_GOOD_APIC, try M686 (Pentium-Pro) - but that won't enable MMX and SSE (via -march=c3-2). These CPUs support SSE2 too... there should probably be an option for C7 that passes 686/mmx/sse/sse2 to gcc. (The c3-2 option could even cause gcc to alter code for the C3-2 that's not necessary for the C7, but I've not checked what else gcc does with -march=c3-2). Also, for the C7 you'll want CRYPTO_DEV_PADLOCK_* (Hardware Crypto Devices, Support for VIA PadLock ACE) and HW_RANDOM_VIA (VIA HW Random Number Generator support). -- Simon Arlott [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 829 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Which CPU for VIA C7/Esther? 2007-02-12 23:46 ` Simon Arlott @ 2007-02-12 23:59 ` Dave Jones 0 siblings, 0 replies; 5+ messages in thread From: Dave Jones @ 2007-02-12 23:59 UTC (permalink / raw) To: Simon Arlott; +Cc: Kyle McMartin, Mark de Vries, linux-kernel On Mon, Feb 12, 2007 at 11:46:46PM +0000, Simon Arlott wrote: > MVIAC3_2 doesn't enable X86_GOOD_APIC which is pretty irrelevant unless you have a dual C7. > , try M686 (Pentium-Pro) - but that won't enable MMX and SSE (via -march=c3-2). If gcc generated SSE/MMX instructions that would be a bug. (hint: it doesn't). > These CPUs support SSE2 too... The SSE/SSE2/SSE3 etc support for userspace is unconditional. The context switch paths will save/restore the registers regardless of the CPU you've compiled your kernel for. The only SSE code in the kernel is the memcpy code (which wasn't that big a win when I last tried it on VIA due to their poor memory bandwidth), and the RAID code, which gets tested at runtime rather than compile time. > Also, for the C7 you'll want CRYPTO_DEV_PADLOCK_* (Hardware Crypto Devices, Support for VIA PadLock ACE) and HW_RANDOM_VIA (VIA HW Random Number Generator support). Yes. But these aren't dependant on any CPU config options. Dave -- http://www.codemonkey.org.uk ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2007-02-12 23:59 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2007-02-12 17:37 Which CPU for VIA C7/Esther? Mark de Vries 2007-02-12 19:14 ` Kyle McMartin 2007-02-12 20:16 ` Dave Jones 2007-02-12 23:46 ` Simon Arlott 2007-02-12 23:59 ` Dave Jones
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