From: YueHaibing <yuehaibing@huawei.com>
To: Kalle Valo <kvalo@codeaurora.org>
Cc: Maya Erez <merez@codeaurora.org>,
<linux-wireless@vger.kernel.org>, <wil6210@qti.qualcomm.com>,
<kernel-janitors@vger.kernel.org>, <netdev@vger.kernel.org>
Subject: Re: [PATCH] wil6210: fix debugfs_simple_attr.cocci warnings
Date: Fri, 5 Oct 2018 19:51:18 +0800 [thread overview]
Message-ID: <08e22040-6e8d-75d1-c0ec-37818435eeba@huawei.com> (raw)
In-Reply-To: <877eiw1wol.fsf@codeaurora.org>
On 2018/10/5 19:04, Kalle Valo wrote:
> YueHaibing <yuehaibing@huawei.com> writes:
>
>> Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE
>> for debugfs files.
>>
>> Semantic patch information:
>> Rationale: DEFINE_SIMPLE_ATTRIBUTE + debugfs_create_file()
>> imposes some significant overhead as compared to
>> DEFINE_DEBUGFS_ATTRIBUTE + debugfs_create_file_unsafe().
>>
>> Generated by: scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci
>
> Just out of curiosity, what kind of overhead are we talking about here?
commit 5103068eaca2 ("debugfs, coccinelle: check for obsolete DEFINE_SIMPLE_ATTRIBUTE() usage")
said this:
In order to protect against file removal races, debugfs files created via
debugfs_create_file() now get wrapped by a struct file_operations at their
opening.
If the original struct file_operations are known to be safe against removal
races by themselves already, the proxy creation may be bypassed by creating
the files through debugfs_create_file_unsafe().
In order to help debugfs users who use the common
DEFINE_SIMPLE_ATTRIBUTE() + debugfs_create_file()
idiom to transition to removal safe struct file_operations, the helper
macro DEFINE_DEBUGFS_ATTRIBUTE() has been introduced.
>
next prev parent reply other threads:[~2018-10-05 11:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-05 11:07 [PATCH] wil6210: fix debugfs_simple_attr.cocci warnings YueHaibing
2018-10-05 11:04 ` Kalle Valo
2018-10-05 11:51 ` YueHaibing [this message]
2018-10-05 14:29 ` Julia Lawall
2018-10-06 12:11 ` Kalle Valo
2018-10-06 12:22 ` Julia Lawall
2018-10-06 12:54 ` Kalle Valo
2018-10-13 17:29 ` Kalle Valo
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