• Anton Blanchard's avatar
    [PATCH] ppc64: exception path optimisations · 1fcedc2b
    Anton Blanchard authored
    - We were statically predicting syscalls would be 32bit which meant every
      64bit syscall was guaranteed to be mispredicted. Just let the hardware
      predict this one.
    
    - We shouldnt use blrl for indirect function calls, it is unlikely to be
      predicted correctly and corrupts the link prediction stack. We should
      use bctrl instead.
    
    - Statically predict a branch in the system call path, favouring calls from
      userspace.
    
    - Remove static prediction in pagefault path, hardware prediction should do
      a better job here.
    Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    1fcedc2b
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