• Sebastien Rannou's avatar
    cpuidle: mvebu: Update cpuidle thresholds for Armada XP SOCs · ce6031c8
    Sebastien Rannou authored
    Originally, the thresholds used in the cpuidle driver for Armada SOCs
    were temporarily chosen, leaving room for improvements.
    
    This commit updates the thresholds for the Armada XP SOCs with values
    that positively impact performances:
    
                                    without patch  with patch   vendor kernel
     - iperf localhost (gbit/sec)   ~3.7           ~6.4         ~5.4
     - ioping tmpfs (iops)          ~163k          ~206k        ~179k
     - ioping tmpfs (mib/s)         ~636           ~805         ~699
    
    The idle power consumption is negatively impacted (proportionally less
    than the performance gain), and we are still performing better than
    the vendor kernel here:
    
                                    without patch   with patch  vendor kernel
     - power consumption idle (W)   ~2.4            ~3.2        ~4.4
     - power consumption busy (W)   ~8.6            ~8.3        ~8.6
    
    There is still room for improvement regarding the value of these
    thresholds, they were chosen to mimic the vendor kernel.
    
    This patch only impacts Armada XP SOCs and was tested on Online Labs
    C1 boards. A similar approach can be taken to improve the performances
    of the Armada 370 and Armada 38x SOCs.
    
    Thanks a lot to Thomas Petazzoni, Gregory Clement and Willy Tarreau
    for the discussions and tips around this topic.
    Signed-off-by: default avatarSebastien Rannou <mxs@sbrk.org>
    Signed-off-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
    Acked-by: default avatarGregory CLEMENT <gregory.clement@free-electrons.com>
    ce6031c8
cpuidle-mvebu-v7.c 3.53 KB