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AJvYcCXhROqtfuky181qH93vrtMcYeMB7+Eq5iMxn4dMTWtlJdQWd7ujY9XAJ6KWHjP6/FBmX9EOIUZIluDFo9Nz6w==@vger.kernel.org X-Gm-Message-State: AOJu0YzJg9gvjDZbbDUYXY+5v6QSETWsM0bXiBZjA2ejwCdzNMCRlTmF I5ooEvCy2tDUVhbEaoVJWXIDN74rdzFWECTAr5RmiaFglq1B/HiUVltCmFIohSi/qgK18I0HQaD MprHQoc9ME89T/eHhgiSgvHzYHoyjQhdiaSxj X-Google-Smtp-Source: AGHT+IFw6uM5+6C7SMH67mk+Hc1sAMfXhD2yPqK2binLtdR+dEflXw9OzVkLv56wMCTjpeR0STCBxEH2wN1oY363ons= X-Received: by 2002:a05:6a20:d81a:b0:1d3:5202:f9a8 with SMTP id adf61e73a8af0-1d6dfa3b32bmr18029273637.15.1728311082348; Mon, 07 Oct 2024 07:24:42 -0700 (PDT) Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20241005122531.20298-1-fujita.tomonori@gmail.com> <20241005122531.20298-4-fujita.tomonori@gmail.com> <20241007.151707.748215468112346610.fujita.tomonori@gmail.com> In-Reply-To: <20241007.151707.748215468112346610.fujita.tomonori@gmail.com> From: Alice Ryhl Date: Mon, 7 Oct 2024 16:24:28 +0200 Message-ID: Subject: Re: [PATCH net-next v2 3/6] rust: time: Implement addition of Ktime and Delta To: FUJITA Tomonori Cc: anna-maria@linutronix.de, frederic@kernel.org, tglx@linutronix.de, miguel.ojeda.sandonis@gmail.com, netdev@vger.kernel.org, rust-for-linux@vger.kernel.org, andrew@lunn.ch, hkallweit1@gmail.com, tmgross@umich.edu, ojeda@kernel.org, alex.gaynor@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@samsung.com, arnd@arndb.de, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, Oct 7, 2024 at 8:17=E2=80=AFAM FUJITA Tomonori wrote: > > On Sat, 5 Oct 2024 20:36:44 +0200 > Miguel Ojeda wrote: > > > On Sat, Oct 5, 2024 at 2:26=E2=80=AFPM FUJITA Tomonori > > wrote: > >> > >> + fn add(self, delta: Delta) -> Ktime { > >> + // SAFETY: FFI call. > >> + let t =3D unsafe { bindings::ktime_add_ns(self.inner, delta.a= s_nanos() as u64) }; > >> + Ktime::from_raw(t) > >> + } > > > > I wonder if we want to use the `ktime` macros/operations for this type > > or not (even if we still promise it is the same type underneath). It > > means having to define helpers, adding `unsafe` code and `SAFETY` > > comments, a call penalty in non-LTO, losing overflow checking (if we > > want it for these types), and so on. > > Yeah, if we are allowed to touch ktime_t directly instead of using the > accessors, it's great for the rust side. > > The timers maintainers, what do you think? We already do that in the existing code. The Ktime::sub method touches the ktime_t directly and performs a subtraction using the - operator rather than call a ktime_ method for it. Alice