• Anton Blanchard's avatar
    [PATCH] powerpc: Fix runlatch performance issues · cb2c9b27
    Anton Blanchard authored
    The runlatch SPR can take a lot of time to write. My original runlatch
    code would set it on every exception entry even though most of the time
    this was not required. It would also continually set it in the idle
    loop, which is an issue on an SMT capable processor.
    
    Now we cache the runlatch value in a threadinfo bit, and only check for
    it in decrementer and hardware interrupt exceptions as well as the idle
    loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32.
    Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    cb2c9b27
head_64.S 51.9 KB