On Sat, Oct 26, 2019 at 11:23:59AM +0800, Zhenzhong Duan wrote:
> Ensure pool time is longer than block_ns, so there is a margin to
> avoid vCPU get into block state unnecessorily.
>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxxx>
> ---
> drivers/cpuidle/governors/haltpoll.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/cpuidle/governors/haltpoll.c b/drivers/cpuidle/governors/haltpoll.c
> index 4b00d7a..59eadaf 100644
> --- a/drivers/cpuidle/governors/haltpoll.c
> +++ b/drivers/cpuidle/governors/haltpoll.c
> @@ -81,9 +81,9 @@ static void adjust_poll_limit(struct cpuidle_device *dev, unsigned int block_us)
> u64 block_ns = block_us*NSEC_PER_USEC;
>
> /* Grow cpu_halt_poll_us if
> - * cpu_halt_poll_us < block_ns < guest_halt_poll_us
> + * cpu_halt_poll_us <= block_ns < guest_halt_poll_us
> */
> - if (block_ns > dev->poll_limit_ns && block_ns <= guest_halt_poll_ns) {
> + if (block_ns >= dev->poll_limit_ns && block_ns < guest_halt_poll_ns) {
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
If block_ns == guest_halt_poll_ns, you won't allow dev->poll_limit_ns to
grow. Why is that?
> @@ -101,7 +101,7 @@ static void adjust_poll_limit(struct cpuidle_device *dev, unsigned int block_us)
> val = guest_halt_poll_ns;
>
> dev->poll_limit_ns = val;
> - } else if (block_ns > guest_halt_poll_ns &&
> + } else if (block_ns >= guest_halt_poll_ns &&
> guest_halt_poll_allow_shrink) {
> unsigned int shrink = guest_halt_poll_shrink;
And here you shrink if block_ns == guest_halt_poll_ns. Not sure
why that makes sense either.
