linux-kernel - Re: [PATCH v2] seq_file: copy as much as possible to user buffer in seq

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Message-ID: <1748fa92.b227.193e4f8d6a3.Coremail.00107082@163.com>
Date: Sat, 21 Dec 2024 00:48:53 +0800 (CST)
From: "David Wang" <00107082@....com>
To: "Markus Elfring" <Markus.Elfring@....de>
Cc: linux-fsdevel@...r.kernel.org, "Alexander Viro" <viro@...iv.linux.org.uk>, 
	"Christian Brauner" <brauner@...nel.org>, 
	LKML <linux-kernel@...r.kernel.org>, 
	"Suren Baghdasaryan" <surenb@...gle.com>
Subject: Re: [PATCH v2] seq_file: copy as much as possible to user buffer in
 seq_read()



At 2024-12-20 22:34:12, "Markus Elfring" <Markus.Elfring@....de> wrote:
>> seq_read() yields at most seq_file->size bytes to userspace, …
>
>                                                    user space?
>
>
>…
>> 	$ strace -T -e read cat /proc/interrupts  > /dev/null
>…
>> 	 45 read(3, "", 131072)                     = 0 <0.000010>
>> On a system with hundreds of cpus, it would need …
>
>                               CPUs?
>
>
>Is it a bit nicer to separate test output and subsequent comments by blank lines?
>
>
>…
>> Fill up user buffer as much as possible in seq_read(), extra read
>> calls can be avoided with a larger user buffer, and 2%~10% performance
>> improvement would be observed:
>Will it help to split such a paragraph into three sentences
>(on separate lines)?
>
>Regards,
>Markus

Thanks for the comments, I will address it later.
Any concern about the code?

David