Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Mon, 1 Nov 2021 12:25:52 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     Gou Hao <gouhao@uniontech.com>
Cc:     viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, jiaofenfang@uniontech.com
Subject: Re: [PATCH] fs: remove fget_many and fput_many interface
Message-ID: <YX/c0IKikjZ5DAlG@casper.infradead.org>
References: <20211101051931.21544-1-gouhao@uniontech.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20211101051931.21544-1-gouhao@uniontech.com>
Precedence: bulk

On Mon, Nov 01, 2021 at 01:19:31PM +0800, Gou Hao wrote:
> From: gouhao <gouhao@uniontech.com>
> 
> These two interface were added in 091141a42 commit,
> but now there is no place to call them.

For completeness, the only user of these APIs was removed in commit
62906e89e63b ("io_uring: remove file batch-get optimisation").
A user of get_file_rcu_many() (which you didn't mention) were also
removed in f073531070d2 ("init: add an init_dup helper").

> And replace atomic_long_sub/add to atomic_long_dec/inc
> can improve performance.
> 
> Here are the test results of unixbench:
> 
> Cmd: ./Run -c 64 context1
> 
> Without patch:
> System Benchmarks Partial Index              BASELINE       RESULT    INDEX
> Pipe-based Context Switching                   4000.0    2798407.0   6996.0
>                                                                    ========
> System Benchmarks Index Score (Partial Only)                         6996.0
> 
> With patch:
> System Benchmarks Partial Index              BASELINE       RESULT    INDEX
> Pipe-based Context Switching                   4000.0    3486268.8   8715.7
>                                                                    ========
> System Benchmarks Index Score (Partial Only)                         8715.7

This seems impressive.  What's the stddev of this benchmark?