1. 07 7月, 2010 1 次提交
    • S
      x86: Avoid unnecessary __clear_user() and xrstor in signal handling · 8e221b6d
      Suresh Siddha 提交于
      fxsave/xsave doesn't touch all the bytes in the memory layout used by
      these instructions. Specifically SW reserved (bytes 464..511) fields
      in the fxsave frame and the reserved fields in the xsave header.
      
      To present a clean context for the signal handling, just clear these fields
      instead of clearing the complete fxsave/xsave memory layout, when we dump these
      registers directly to the user signal frame.
      
      Also avoid the call to second xrstor (which inits the state not passed
      in the signal frame) in restore_user_xstate() if all the state has already
      been restored by the first xrstor.
      
      These changes improve the performance of signal handling(by ~3-5% as measured
      by the lat_sig).
      Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
      LKML-Reference: <1277249017.2847.85.camel@sbs-t61.sc.intel.com>
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      8e221b6d
  2. 05 7月, 2010 9 次提交
  3. 03 7月, 2010 7 次提交
  4. 02 7月, 2010 23 次提交