Messages in this thread | | | Date | Mon, 19 Jul 2010 16:05:47 -0700 | From | Suresh Siddha <> | Subject | [patch 0/5] x86: xsaveopt kernel enabling patches - v2 |
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AVX Programming Reference (June, 2010 version) located at http://software.intel.com/en-us/avx/ refers to the optimized extended state save instruction "xsaveopt".
xsaveopt is similar to xsave and incorporates optimizations specifically targeted for speeding up context switch save, like: a. if a state is in an INIT state, the instruction may clear the corresponding bit in the xheader.bv with out writing the actual state in to the memory. b. if the state hasn't been modified since the last xrstor, the instruction may not write out the state to the save area.
Following patches enable the use of xsaveopt for context switch save/restore of the extended state.
changes in v2: Split the cpu feature detection bits in to multiple patches along with the misc changes in the init_scattered_cpuid_features() -- Requested by hpa.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
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