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Date:   Wed, 19 Jul 2023 08:04:22 +0200
From:   Christian Brauner <brauner@kernel.org>
To:     Hao Xu <hao.xu@linux.dev>
Cc:     io-uring@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
        Dominique Martinet <asmadeus@codewreck.org>,
        Pavel Begunkov <asml.silence@gmail.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Stefan Roesch <shr@fb.com>, Clay Harris <bugs@claycon.org>,
        Dave Chinner <david@fromorbit.com>,
        linux-fsdevel@vger.kernel.org, Wanpeng Li <wanpengli@tencent.com>
Subject: Re: [PATCH v4 0/5] io_uring getdents
Message-ID: <20230719-sitzkissen-mehrverbrauch-612a4dfcdeb5@brauner>
References: <20230718132112.461218-1-hao.xu@linux.dev>
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On Tue, Jul 18, 2023 at 09:21:07PM +0800, Hao Xu wrote:
> From: Hao Xu <howeyxu@tencent.com>
> 
> This series introduce getdents64 to io_uring, the code logic is similar
> with the snychronized version's. It first try nowait issue, and offload
> it to io-wq threads if the first try fails.
> 
> Tested it with a liburing case:
> https://github.com/HowHsu/liburing/blob/getdents/test/getdents2.c
> 
> The test is controlled by the below script[2] which runs getdents2.t 100
> times and calulate the avg.
> The result show that io_uring version is about 3% faster:
> 
> python3 run_getdents.py
>     Average of sync: 0.1036849
>     Average of iouring: 0.1005568
> 
> (0.1036849-0.1005568)/0.1036849 = 3.017%
> 
> note:
> [1] the number of getdents call/request in io_uring and normal sync version
> are made sure to be same beforehand.
> 
> [2] run_getdents.py
> 
> ```python3
> 
> import subprocess
> 
> N = 100
> sum = 0.0
> args = ["/data/home/howeyxu/tmpdir", "sync"]
> 
> for i in range(N):
>     output = subprocess.check_output(["./liburing/test/getdents2.t"] + args)
>     sum += float(output)
> 
> average = sum / N
> print("Average of sync:", average)
> 
> sum = 0.0
> args = ["/data/home/howeyxu/tmpdir", "iouring"]
> 
> for i in range(N):
>     output = subprocess.check_output(["./liburing/test/getdents2.t"] + args)
>     sum += float(output)
> 
> average = sum / N
> print("Average of iouring:", average)
> 
> ```
> 
> v3->v4:

I'm out this week so will review next week.