linux-kernel - Re: [PATCH v1 0/3] PM: runtime: Wrapper macros for usage counter guards

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Message-ID: <20251110120650.00004de8@huawei.com>
Date: Mon, 10 Nov 2025 12:06:50 +0000
From: Jonathan Cameron <jonathan.cameron@...wei.com>
To: "Rafael J. Wysocki" <rafael@...nel.org>
CC: Linux PM <linux-pm@...r.kernel.org>, Linux ACPI
	<linux-acpi@...r.kernel.org>, Takashi Iwai <tiwai@...e.de>, LKML
	<linux-kernel@...r.kernel.org>, Zhang Qilong <zhangqilong3@...wei.com>, Frank
 Li <Frank.Li@....com>, Dhruva Gole <d-gole@...com>, Dan Williams
	<dan.j.williams@...el.com>, Linux PCI <linux-pci@...r.kernel.org>, "Bjorn
 Helgaas" <helgaas@...nel.org>, Alex Williamson <alex.williamson@...hat.com>
Subject: Re: [PATCH v1 0/3] PM: runtime: Wrapper macros for usage counter
 guards

On Fri, 07 Nov 2025 19:35:09 +0100
"Rafael J. Wysocki" <rafael@...nel.org> wrote:

> Hi All,
> 
> The runtime PM usage counter guards introduced recently:
> 
> https://lore.kernel.org/linux-pm/6196611.lOV4Wx5bFT@rafael.j.wysocki/
> 
> and then fixed:
> 
> https://lore.kernel.org/linux-pm/5943878.DvuYhMxLoT@rafael.j.wysocki/
> 
> should generally work, but using them feels sort of arcane and cryptic
> even though the underlying concept is relatively straightforward.
> 
> For this reason, runtime PM wrapper macros around ACQUIRE() and
> ACQUIRE_ERR() involving the new guards are introduced in this series
> (patch [1/3]) and then used in the code already using the guards (patches
> [2/3] and [3/3]) to make it look more straightforward.
> 
> Thanks!

It's an interesting trade off between completely hiding the magic variables
and verbosity.  The PM_RUNTIME_ACQUIRE_ERR smells like something we'd
expect to be using global state (given no parameters), but it is of
course just local with a magic name.  Will take a little getting
used to but then so does all this cleanup.h magic.  So on balance
I think this is a good change.

Reviewed-by: Jonathan Cameron <jonathan.cameron@...wei.com>