Messages in this thread | | | Subject | Re: [PATCH 07/10] x86/xsaves: Fix init_fpstate.header.xcomp_bv | From | Dave Hansen <> | Date | Mon, 22 Feb 2016 11:55:50 -0800 |
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On 02/22/2016 10:59 AM, Yu-cheng Yu wrote: > This actually does not apply to XSAVES as XSAVES uses optimization. After > init, all components are in INIT and not MODIFIED state and will not be > saved. There is no need of setting xcomp_bv except for bit 63 to indicate > a compacted format.
I look at it this way: xcomp_bv tells you the format of the buffer xstate_bv tells you which components of the buffer are valid (not in init state).
As it stands, every kernel xcomp_bv value should be identical, since the kernel buffer is always in the same state and XSAVES is always called with the same Requested Feature BitMap (RFBM).
While I don't think this patch _hurts_ anything, I think it might be a bit confusing. Wouldn't it just be easier if *EVERY* xcomp_bv value was the same?
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