linux-kernel - Re: [PATCH v2] driver core: auxiliary bus: Optimize logic of auxiliary_match

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Message-ID: <2159c5bf-1ce3-4fd7-81e3-f458efca8548@icloud.com>
Date: Thu, 4 Sep 2025 07:00:37 +0800
From: Zijun Hu <zijun_hu@...oud.com>
To: Danilo Krummrich <dakr@...nel.org>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
 Dave Ertman <david.m.ertman@...el.com>, Ira Weiny <ira.weiny@...el.com>,
 Leon Romanovsky <leon@...nel.org>, "Rafael J. Wysocki" <rafael@...nel.org>,
 linux-kernel@...r.kernel.org, Zijun Hu <zijun.hu@....qualcomm.com>
Subject: Re: [PATCH v2] driver core: auxiliary bus: Optimize logic of
 auxiliary_match_id()

On 2025/9/3 19:46, Danilo Krummrich wrote:
>>  static const struct auxiliary_device_id *auxiliary_match_id(const struct auxiliary_device_id *id,
>>  							    const struct auxiliary_device *auxdev)
>>  {
>> -	for (; id->name[0]; id++) {
>> -		const char *p = strrchr(dev_name(&auxdev->dev), '.');
>> -		int match_size;
>> +	const char *auxdev_name = dev_name(&auxdev->dev);
> I feel like this is a bit too ambitious. Using dev_name() directly for the calls
> below seems more obvious to me.
> 

dev_name(&auxdev->dev) which is a inline function appears 3 times in the
for loop. may be worthy of a new variable

> Yes, dev_name() contains a branch, but I'm pretty sure the compiler optimizes
> them away for subsequent calls anyways.

>From debugging perspective:
more difficult to debug if more the compiler optimizes.