Messages in this thread | | | Subject | Re: [PATCH v3 1/5] wbt: don't show valid wbt_lat_usec in sysfs while wbt is disabled | From | Yu Kuai <> | Date | Mon, 26 Sep 2022 21:01:41 +0800 |
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Hi, Jan
在 2022/09/26 19:47, Jan Kara 写道: > On Mon 26-09-22 18:25:18, Yu Kuai wrote: >> Hi, Jan >> >> 在 2022/09/26 17:44, Jan Kara 写道: >>> On Thu 22-09-22 19:35:54, Yu Kuai wrote: >>>> Currently, if wbt is initialized and then disabled by >>>> wbt_disable_default(), sysfs will still show valid wbt_lat_usec, which >>>> will confuse users that wbt is still enabled. >>>> >>>> This patch shows wbt_lat_usec as zero and forbid to set it while wbt >>>> is disabled. >>> >>> So I agree we should show 0 in wbt_lat_usec if wbt is disabled by >>> wbt_disable_default(). But why do you forbid setting of wbt_lat_usec? >>> IMHO if wbt_lat_usec is set, admin wants to turn on wbt so we should just >>> update rwb->enable_state to WBT_STATE_ON_MANUAL. >> >> I was thinking that don't enable wbt if elevator is bfq. Since we know >> that performance is bad, thus it doesn't make sense to me to do that, >> and user might doesn't aware of the problem. > > Yeah, I don't think it is a good idea (that is the reason why it is > disabled by default) but in priciple I don't see a reason why we should > block admin from enabling it.
I'll enable it in next version.
Thanks, Kuai
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