From: Andreas Hindborg <a.hindborg@kernel•org>
To: "Boqun Feng" <boqun.feng@gmail•com>
Cc: "FUJITA Tomonori" <fujita.tomonori@gmail•com>,
<rust-for-linux@vger•kernel.org>, "Gary Guo" <gary@garyguo•net>,
"Fiona Behrens" <me@kloenk•dev>,
"Daniel Almeida" <daniel.almeida@collabora•com>,
<linux-kernel@vger•kernel.org>, <netdev@vger•kernel.org>,
<andrew@lunn•ch>, <hkallweit1@gmail•com>, <tmgross@umich•edu>,
<ojeda@kernel•org>, <alex.gaynor@gmail•com>,
<bjorn3_gh@protonmail•com>, <benno.lossin@proton•me>,
<a.hindborg@samsung•com>, <aliceryhl@google•com>,
<anna-maria@linutronix•de>, <frederic@kernel•org>,
<tglx@linutronix•de>, <arnd@arndb•de>, <jstultz@google•com>,
<sboyd@kernel•org>, <mingo@redhat•com>, <peterz@infradead•org>,
<juri.lelli@redhat•com>, <vincent.guittot@linaro•org>,
<dietmar.eggemann@arm•com>, <rostedt@goodmis•org>,
<bsegall@google•com>, <mgorman@suse•de>, <vschneid@redhat•com>,
<tgunders@redhat•com>, <david.laight.linux@gmail•com>
Subject: Re: [PATCH v13 3/5] rust: time: Introduce Instant type
Date: Mon, 14 Apr 2025 09:04:14 +0200 [thread overview]
Message-ID: <87lds3cjgx.fsf@kernel.org> (raw)
In-Reply-To: <67fc517b.050a0220.301460.dfe7@mx.google.com> (Boqun Feng's message of "Sun, 13 Apr 2025 17:06:15 -0700")
"Boqun Feng" <boqun.feng@gmail•com> writes:
> On Sun, Apr 13, 2025 at 07:43:08PM +0900, FUJITA Tomonori wrote:
>> Introduce a type representing a specific point in time. We could use
>> the Ktime type but C's ktime_t is used for both timestamp and
>> timedelta. To avoid confusion, introduce a new Instant type for
>> timestamp.
>>
>> Rename Ktime to Instant and modify their methods for timestamp.
>>
>> Implement the subtraction operator for Instant:
>>
>> Delta = Instant A - Instant B
>>
>> Reviewed-by: Boqun Feng <boqun.feng@gmail•com>
>
> I probably need to drop my Reviewed-by because of something below:
>
>> Reviewed-by: Gary Guo <gary@garyguo•net>
>> Reviewed-by: Fiona Behrens <me@kloenk•dev>
>> Tested-by: Daniel Almeida <daniel.almeida@collabora•com>
>> Reviewed-by: Andreas Hindborg <a.hindborg@kernel•org>
>> Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail•com>
>> ---
> [...]
>> diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs
>> index ce53f8579d18..27243eaaf8ed 100644
>> --- a/rust/kernel/time/hrtimer.rs
>> +++ b/rust/kernel/time/hrtimer.rs
>> @@ -68,7 +68,7 @@
>> //! `start` operation.
>>
>> use super::ClockId;
>> -use crate::{prelude::*, time::Ktime, types::Opaque};
>> +use crate::{prelude::*, time::Instant, types::Opaque};
>> use core::marker::PhantomData;
>> use pin_init::PinInit;
>>
>> @@ -189,7 +189,7 @@ pub trait HrTimerPointer: Sync + Sized {
>>
>> /// Start the timer with expiry after `expires` time units. If the timer was
>> /// already running, it is restarted with the new expiry time.
>> - fn start(self, expires: Ktime) -> Self::TimerHandle;
>> + fn start(self, expires: Instant) -> Self::TimerHandle;
>
> We should be able to use what I suggested:
>
> https://lore.kernel.org/rust-for-linux/Z_ALZsnwN53ZPBrB@boqun-archlinux/
>
> to make different timer modes (rel or abs) choose different expire type.
>
> I don't think we can merge this patch as it is, unfortunately, because
> it doesn't make sense for a relative timer to take an Instant as expires
> value.
I told Tomo he could use `Instant` in this location and either he or I
would fix it up later [1].
I don't want to block the series on this since the new API is not worse
than the old one where Ktime is overloaded for both uses.
Best regards,
Andreas Hindborg
[1] https://lore.kernel.org/all/877c41v7kf.fsf@kernel.org
next prev parent reply other threads:[~2025-04-14 7:04 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-13 10:43 [PATCH v13 0/5] rust: Add IO polling FUJITA Tomonori
2025-04-13 10:43 ` [PATCH v13 1/5] rust: time: Add PartialEq/Eq/PartialOrd/Ord trait to Ktime FUJITA Tomonori
2025-04-13 10:43 ` [PATCH v13 2/5] rust: time: Introduce Delta type FUJITA Tomonori
2025-04-13 10:43 ` [PATCH v13 3/5] rust: time: Introduce Instant type FUJITA Tomonori
2025-04-14 0:06 ` Boqun Feng
2025-04-14 7:04 ` Andreas Hindborg [this message]
2025-04-14 11:59 ` FUJITA Tomonori
2025-04-15 18:01 ` Boqun Feng
2025-04-16 3:46 ` FUJITA Tomonori
2025-04-22 10:07 ` Andreas Hindborg
2025-04-22 13:50 ` FUJITA Tomonori
2025-04-13 10:43 ` [PATCH v13 4/5] rust: time: Add wrapper for fsleep() function FUJITA Tomonori
2025-04-13 10:43 ` [PATCH v13 5/5] MAINTAINERS: rust: Add a new section for all of the time stuff FUJITA Tomonori
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87lds3cjgx.fsf@kernel.org \
--to=a.hindborg@kernel$(echo .)org \
--cc=a.hindborg@samsung$(echo .)com \
--cc=alex.gaynor@gmail$(echo .)com \
--cc=aliceryhl@google$(echo .)com \
--cc=andrew@lunn$(echo .)ch \
--cc=anna-maria@linutronix$(echo .)de \
--cc=arnd@arndb$(echo .)de \
--cc=benno.lossin@proton$(echo .)me \
--cc=bjorn3_gh@protonmail$(echo .)com \
--cc=boqun.feng@gmail$(echo .)com \
--cc=bsegall@google$(echo .)com \
--cc=daniel.almeida@collabora$(echo .)com \
--cc=david.laight.linux@gmail$(echo .)com \
--cc=dietmar.eggemann@arm$(echo .)com \
--cc=frederic@kernel$(echo .)org \
--cc=fujita.tomonori@gmail$(echo .)com \
--cc=gary@garyguo$(echo .)net \
--cc=hkallweit1@gmail$(echo .)com \
--cc=jstultz@google$(echo .)com \
--cc=juri.lelli@redhat$(echo .)com \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=me@kloenk$(echo .)dev \
--cc=mgorman@suse$(echo .)de \
--cc=mingo@redhat$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
--cc=ojeda@kernel$(echo .)org \
--cc=peterz@infradead$(echo .)org \
--cc=rostedt@goodmis$(echo .)org \
--cc=rust-for-linux@vger$(echo .)kernel.org \
--cc=sboyd@kernel$(echo .)org \
--cc=tglx@linutronix$(echo .)de \
--cc=tgunders@redhat$(echo .)com \
--cc=tmgross@umich$(echo .)edu \
--cc=vincent.guittot@linaro$(echo .)org \
--cc=vschneid@redhat$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox