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Subject: Re: [PATCH V2] arm64: psci: Reduce waiting time of
 cpu_psci_cpu_kill()
To:     David Laight <David.Laight@ACULAB.COM>,
        Sudeep Holla <sudeep.holla@arm.com>
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        "will@kernel.org" <will@kernel.org>,
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        "hushiyuan@huawei.com" <hushiyuan@huawei.com>,
        "linfeilong@huawei.com" <linfeilong@huawei.com>
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 <20191016153221.GA8978@bogus>
 <0f550044-9ed2-5f72-1335-73417678ba45@huawei.com>
 <c97c87b52f474463bc30ff8033a57e0c@AcuMS.aculab.com>
From:   Yunfeng Ye <yeyunfeng@huawei.com>
Message-ID: <1cd555f0-4074-36b7-8426-6f01130051d2@huawei.com>
Date:   Thu, 17 Oct 2019 22:19:54 +0800
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On 2019/10/17 22:00, David Laight wrote:
> From: Yunfeng Ye
>> Sent: 17 October 2019 14:26
> ...
>>>> -	for (i = 0; i < 10; i++) {
>>>> +	i = 0;
>>>> +	timeout = jiffies + msecs_to_jiffies(100);
>>>> +	do {
>>>>  		err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
>>>>  		if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) {
>>>>  			pr_info("CPU%d killed.\n", cpu);
>>>>  			return 0;
>>>>  		}
>>>>
>>>> -		msleep(10);
>>>> -		pr_info("Retrying again to check for CPU kill\n");
>>>
>>> You dropped this message, any particular reason ?
>>>
>> When reduce the time interval to 1ms, the print message maybe increase 10 times.
>> on the other hand, cpu_psci_cpu_kill() will print message on success or failure, which
>> this retry log is not very necessary. of cource, I think use pr_info_once() instead of
>> pr_info() is better.
> 
> Maybe you should print in on (say) the 10th time around the loop.
> 
Can it like this:
  pr_info("CPU%d killed with %d loops.\n", cpu, loops);

If put the number of waiting times in the successful printing message, it is
not necessary to print the "Retrying ..." message.

thanks.

> 	David
> 
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
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