Re: [patch] x86, avx: don't use avx instructions with "noxsave" boot param

2012-08-01 Thread NeilBrown
On Tue, 31 Jul 2012 10:29:14 -0700 Suresh Siddha wrote: > On Tue, 2012-07-31 at 09:43 -0700, H. Peter Anvin wrote: > > My main reason for thinking that it would be good to clear the bits is > > that it plays a lot nicer with alternatives and with static_cpu_has(). > > Fair enough. Neil, can you

Re: [patch] x86, avx: don't use avx instructions with "noxsave" boot param

2012-07-31 Thread Suresh Siddha
On Tue, 2012-07-31 at 09:43 -0700, H. Peter Anvin wrote: > My main reason for thinking that it would be good to clear the bits is > that it plays a lot nicer with alternatives and with static_cpu_has(). Fair enough. Neil, can you please drop the previous patch and Peter, please queue this for v3.

Re: [patch] x86, avx: don't use avx instructions with "noxsave" boot param

2012-07-31 Thread H. Peter Anvin
On 07/31/2012 09:27 AM, Suresh Siddha wrote: On Mon, 2012-07-30 at 21:33 -0700, H. Peter Anvin wrote: I'm wondering if we shouldn't just kill the affected CPUID bits if osxsave is off... Yes, I considered clearing AVX bit (and any future xsave feature bits) as part of the parsing "noxsave" pa

Re: [patch] x86, avx: don't use avx instructions with "noxsave" boot param

2012-07-31 Thread Suresh Siddha
On Mon, 2012-07-30 at 21:33 -0700, H. Peter Anvin wrote: > I'm wondering if we shouldn't just kill the affected CPUID bits if osxsave is > off... Yes, I considered clearing AVX bit (and any future xsave feature bits) as part of the parsing "noxsave" parameter in x86_xsave_setup(). But thought ch

Re: [patch] x86, avx: don't use avx instructions with "noxsave" boot param

2012-07-30 Thread H. Peter Anvin
I'm wondering if we shouldn't just kill the affected CPUID bits if osxsave is off... NeilBrown wrote: >On Mon, 30 Jul 2012 15:46:15 -0700 Suresh Siddha > >wrote: > >> Check the kernel has indeed enabled xsave before using AVX >instructions. >> >> Fixes the kernel boot panic with "noxsave" boot

Re: [patch] x86, avx: don't use avx instructions with "noxsave" boot param

2012-07-30 Thread NeilBrown
On Mon, 30 Jul 2012 15:46:15 -0700 Suresh Siddha wrote: > Check the kernel has indeed enabled xsave before using AVX instructions. > > Fixes the kernel boot panic with "noxsave" boot parameter. > > Signed-off-by: Suresh Siddha Looks consistent with other usage - thanks. Applied. Should it go

[patch] x86, avx: don't use avx instructions with "noxsave" boot param

2012-07-30 Thread Suresh Siddha
Check the kernel has indeed enabled xsave before using AVX instructions. Fixes the kernel boot panic with "noxsave" boot parameter. Signed-off-by: Suresh Siddha --- arch/x86/include/asm/xor_avx.h |4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/xo