Re: Linux patch disabling AVX when eagerfpu is turned off - possibly not required

2016-01-21 Thread H. Peter Anvin
On 01/21/16 13:19, Leonid Shatz wrote: > > Thank you all for your feedback and clarifications. That's was my assumption > that SDM was somewhat misleading, but I was not %100 sure about it. It could > be nice, though to see future releases of SDM taking this issue in account. > It will.

RE: Linux patch disabling AVX when eagerfpu is turned off - possibly not required

2016-01-21 Thread Leonid Shatz
On Thu, Jan 21, 2016 at 01:08:18PM -0800, H. Peter Anvin wrote: >> On 01/21/16 13:03, Yu-cheng Yu wrote: >> > Hello Leonid, >> > >> > You are probably right. Let me check this and get back to you. >> > >> > Thanks, >> > Yu-cheng >> > >> >> The hardware people have gotten back to us and this inc

Re: Linux patch disabling AVX when eagerfpu is turned off - possibly not required

2016-01-21 Thread Yu-cheng Yu
On Thu, Jan 21, 2016 at 01:08:18PM -0800, H. Peter Anvin wrote: > On 01/21/16 13:03, Yu-cheng Yu wrote: > > Hello Leonid, > > > > You are probably right. Let me check this and get back to you. > > > > Thanks, > > Yu-cheng > > > > The hardware people have gotten back to us and this inconsistency

Re: Linux patch disabling AVX when eagerfpu is turned off - possibly not required

2016-01-21 Thread H. Peter Anvin
On 01/21/16 13:03, Yu-cheng Yu wrote: > Hello Leonid, > > You are probably right. Let me check this and get back to you. > > Thanks, > Yu-cheng > The hardware people have gotten back to us and this inconsistency in the SDM is unintentional (other places in the SDM has it correctly.) So we shou

Re: Linux patch disabling AVX when eagerfpu is turned off - possibly not required

2016-01-21 Thread Yu-cheng Yu
Hello Leonid, You are probably right. Let me check this and get back to you. Thanks, Yu-cheng

Re: Linux patch disabling AVX when eagerfpu is turned off - possibly not required

2016-01-21 Thread Andy Lutomirski
On Jan 21, 2016 12:12 PM, "H. Peter Anvin" wrote: > > On 01/21/16 12:08, Dave Hansen wrote: > > On 01/21/2016 02:33 AM, Leonid Shatz wrote: > >> In view of above findings we would like to suggest to double check if > >> disabling AVX together with "eagerfpu off" is actually required and is a > >>

Re: Linux patch disabling AVX when eagerfpu is turned off - possibly not required

2016-01-21 Thread H. Peter Anvin
On 01/21/16 12:08, Dave Hansen wrote: > On 01/21/2016 02:33 AM, Leonid Shatz wrote: >> In view of above findings we would like to suggest to double check if >> disabling AVX together with "eagerfpu off" is actually required and is a >> real necessity. It would be helpful to consult with Intel engin

Re: Linux patch disabling AVX when eagerfpu is turned off - possibly not required

2016-01-21 Thread Dave Hansen
On 01/21/2016 02:33 AM, Leonid Shatz wrote: > In view of above findings we would like to suggest to double check if > disabling AVX together with "eagerfpu off" is actually required and is a > real necessity. It would be helpful to consult with Intel engineers > regarding related design details. H

Linux patch disabling AVX when eagerfpu is turned off - possibly not required

2016-01-21 Thread Leonid Shatz
Regarding the patch disabling AVX when eagerfpu is off: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3 94db20ca240741a08d472173db13d6f6a6e5a28 We have a suggestion that Intel documentation related to usage of CR0.TS bit may be not properly updated with additional sup