From: Thomas Gleixner <tglx@linutronix•de>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios•com>,
LKML <linux-kernel@vger•kernel.org>
Cc: "Peter Zijlstra" <peterz@infradead•org>,
"Darren Hart" <dvhart@infradead•org>,
"Davidlohr Bueso" <dave@stgolabs•net>,
"André Almeida" <andrealmeid@igalia•com>,
"kernel test robot" <lkp@intel•com>,
"Russell King" <linux@armlinux•org.uk>,
linux-arm-kernel@lists•infradead.org,
"Linus Torvalds" <torvalds@linux-foundation•org>,
x86@kernel•org, "Madhavan Srinivasan" <maddy@linux•ibm.com>,
"Michael Ellerman" <mpe@ellerman•id.au>,
"Nicholas Piggin" <npiggin@gmail•com>,
"Christophe Leroy" <christophe.leroy@csgroup•eu>,
linuxppc-dev@lists•ozlabs.org, "Paul Walmsley" <pjw@kernel•org>,
"Palmer Dabbelt" <palmer@dabbelt•com>,
linux-riscv@lists•infradead.org,
"Heiko Carstens" <hca@linux•ibm.com>,
"Christian Borntraeger" <borntraeger@linux•ibm.com>,
"Sven Schnelle" <svens@linux•ibm.com>,
linux-s390@vger•kernel.org,
"Andrew Cooper" <andrew.cooper3@citrix•com>,
"David Laight" <david.laight.linux@gmail•com>,
"Julia Lawall" <Julia.Lawall@inria•fr>,
"Nicolas Palix" <nicolas.palix@imag•fr>,
"Alexander Viro" <viro@zeniv•linux.org.uk>,
"Christian Brauner" <brauner@kernel•org>,
"Jan Kara" <jack@suse•cz>,
linux-fsdevel@vger•kernel.org
Subject: Re: [patch V5 10/12] futex: Convert to get/put_user_inline()
Date: Tue, 28 Oct 2025 16:56:03 +0100 [thread overview]
Message-ID: <87frb3uijw.ffs@tglx> (raw)
In-Reply-To: <0c979fe0-ee55-48be-bd0f-9bff71b88a1d@efficios.com>
On Tue, Oct 28 2025 at 10:24, Mathieu Desnoyers wrote:
> On 2025-10-27 04:44, Thomas Gleixner wrote:
>> From: Thomas Gleixner <tglx@linutronix•de>
>>
>> Replace the open coded implementation with the new get/put_user_inline()
>> helpers. This might be replaced by a regular get/put_user(), but that needs
>> a proper performance evaluation.
>
> I understand that this is aiming to keep the same underlying code,
> but I find it surprising that the first user of the "inline" get/put
> user puts the burden of the proof on moving this to regular
> get/put_user() rather than on using the inlined version.
>
> The comment above the inline API clearly states that performance
> numbers are needed to justify the use of inline, not the opposite.
>
> I am concerned that this creates a precedent that may be used by future
> users of the inline API to use it without performance numbers
> justification.
There was not justification for the open coded inline either and
converting it to get/put must be a completely seperate change.
next prev parent reply other threads:[~2025-10-28 15:56 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-27 8:43 [patch V5 00/12] uaccess: Provide and use scopes for user access Thomas Gleixner
2025-10-27 8:43 ` [patch V5 01/12] ARM: uaccess: Implement missing __get_user_asm_dword() Thomas Gleixner
2025-10-28 13:35 ` Mathieu Desnoyers
2025-10-27 8:43 ` [patch V5 02/12] uaccess: Provide ASM GOTO safe wrappers for unsafe_*_user() Thomas Gleixner
2025-10-27 12:12 ` Andrew Cooper
2025-10-28 13:44 ` Mathieu Desnoyers
2025-10-28 14:04 ` Yann Ylavic
2025-10-28 15:53 ` Thomas Gleixner
2025-10-29 9:40 ` [patch V6 " Thomas Gleixner
2025-12-19 8:10 ` patchwork-bot+linux-riscv
2025-11-04 6:11 ` [patch V5 " Christophe Leroy
2025-10-27 8:43 ` [patch V5 03/12] x86/uaccess: Use unsafe wrappers for ASM GOTO Thomas Gleixner
2025-10-28 13:50 ` Mathieu Desnoyers
2025-10-27 8:43 ` [patch V5 04/12] powerpc/uaccess: " Thomas Gleixner
2025-10-28 13:51 ` Mathieu Desnoyers
2025-11-04 6:15 ` Christophe Leroy
2025-10-27 8:43 ` [patch V5 05/12] riscv/uaccess: " Thomas Gleixner
2025-10-28 13:52 ` Mathieu Desnoyers
2025-10-27 8:43 ` [patch V5 06/12] s390/uaccess: " Thomas Gleixner
2025-10-28 13:54 ` Mathieu Desnoyers
2025-10-27 8:43 ` [patch V5 07/12] uaccess: Provide scoped user access regions Thomas Gleixner
2025-10-28 14:11 ` Mathieu Desnoyers
2025-11-04 6:20 ` Christophe Leroy
2025-11-07 19:17 ` David Laight
2025-10-27 8:43 ` [patch V5 08/12] uaccess: Provide put/get_user_inline() Thomas Gleixner
2025-10-28 14:12 ` Mathieu Desnoyers
2025-11-04 6:30 ` Christophe Leroy
2025-10-27 8:43 ` [patch V5 09/12] [RFC] coccinelle: misc: Add scoped_masked_$MODE_access() checker script Thomas Gleixner
2025-10-27 8:44 ` [patch V5 10/12] futex: Convert to get/put_user_inline() Thomas Gleixner
2025-10-28 14:24 ` Mathieu Desnoyers
2025-10-28 15:56 ` Thomas Gleixner [this message]
2025-10-28 16:02 ` Mathieu Desnoyers
2025-10-28 16:13 ` Linus Torvalds
2025-11-04 6:31 ` Christophe Leroy
2025-10-27 8:44 ` [patch V5 11/12] x86/futex: Convert to scoped user access Thomas Gleixner
2025-10-27 8:44 ` [patch V5 12/12] select: " Thomas Gleixner
2025-10-28 14:42 ` Mathieu Desnoyers
2025-11-04 6:32 ` Christophe Leroy
2025-10-27 15:53 ` [patch V5 00/12] uaccess: Provide and use scopes for " Linus Torvalds
2025-10-29 10:23 ` Peter Zijlstra
2025-11-03 14:46 ` Peter Zijlstra
2025-11-04 6:35 ` Christophe Leroy
2025-12-19 8:10 ` patchwork-bot+linux-riscv
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