From: Rafael Folco <rfolco@redhat.com>
To: Crystal Wood <crwood@redhat.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: williams@redhat.com, jkacur@redhat.com, linux-rt-users@vger.kernel.org
Subject: Re: [PATCH] Change min/max to float numbers
Date: Fri, 7 Feb 2025 11:20:37 -0300 [thread overview]
Message-ID: <37c7e3c7-d9fe-4e8a-9b5d-61d041a9151a@redhat.com> (raw)
In-Reply-To: <8144971da4d48d1f3fc75decfff2434fc44f082d.camel@redhat.com>
On 06/02/25 18:23, Crystal Wood wrote:
> On Thu, 2025-02-06 at 12:02 -0300, Rafael Folco wrote:
>> On 06/02/25 09:00, Sebastian Andrzej Siewior wrote:
>>> On 2025-02-06 06:16:22 [-0300], Rafael Folco wrote:
>>>> Make min/max consistent with avg by recording the latency samples
>>>> as float numbers instead of integers.
>>>
>>> Why?
>>
>> - More precise numbers of Max/Min for extreme low latency cases
>> - Distinguish zero latency in bucket 001 (us)
>> - Distinguish values from upper/lower boundaries in a bucket
>> - Clarify confusion on average (round up) vs maximum in the next bucket (casting)
>
> If you want more precision, set --bucket-width to something lower than
> 1000 ns. That will cause everything to be reported with ns precision
> (though maybe not quite ns accuracy, depending on the hardware). We
> were hesitant to make ns precision the default in case it misleads
> people about the accuracy (plus I didn't know if the change might
> confuse some tools that consume the output).
Yes, it works for precision. Average is higher than max with default bucket width, though.
>
> I don't see the need to change things here -- and I definitely don't see
> the need to hold on to the unit_per_us stuff if we're going to always
> print ns resolution, regardless of whether we use fp.
Ack
Thanks for reviewing.
-Folco
>
> -Crystal
>
next prev parent reply other threads:[~2025-02-07 14:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-06 9:16 [PATCH] Change min/max to float numbers Rafael Folco
2025-02-06 12:00 ` Sebastian Andrzej Siewior
2025-02-06 15:02 ` Rafael Folco
2025-02-06 15:09 ` Sebastian Andrzej Siewior
2025-02-06 15:24 ` Rafael Folco
2025-02-06 15:36 ` Sebastian Andrzej Siewior
2025-02-06 16:22 ` Rafael Folco
2025-02-06 21:23 ` Crystal Wood
2025-02-07 14:20 ` Rafael Folco [this message]
2025-02-07 23:23 ` Crystal Wood
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