Re: [PATCH v5] arm64: psci: Reduce the waiting time for cpu_psci_cpu_kill()
From: Sudeep Holla
Date: Mon Oct 21 2019 - 07:21:54 EST
On Mon, Oct 21, 2019 at 06:52:16PM +0800, Yunfeng Ye wrote:
> In cases like suspend-to-disk and suspend-to-ram, a large number of CPU
> cores need to be shut down. At present, the CPU hotplug operation is
> serialised, and the CPU cores can only be shut down one by one. In this
> process, if PSCI affinity_info() does not return LEVEL_OFF quickly,
> cpu_psci_cpu_kill() needs to wait for 10ms. If hundreds of CPU cores
> need to be shut down, it will take a long time.
>
> Normally, there is no need to wait 10ms in cpu_psci_cpu_kill(). So
> change the wait interval from 10 ms to max 1 ms and use usleep_range()
> instead of msleep() for more accurate timer.
>
> In addition, reducing the time interval will increase the messages
> output, so remove the "Retry ..." message, instead, track time and
> output to the the successful message.
Reviewed-by: Sudeep Holla <sudeep.holla@xxxxxxx>
--
Regards,
Sudeep