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References: <20220502102521.22875-1-dharamhans87@gmail.com> <YnLRnR3Xqu0cYPdb@redhat.com>
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From:   Dharmendra Hans <dharamhans87@gmail.com>
Date:   Thu, 5 May 2022 11:42:51 +0530
Message-ID: <CACUYsyEsRph+iFC_fj3F6Ceqhq7NCTuFPH3up8R6C+_bGHktZg@mail.gmail.com>
Subject: Re: [PATCH v4 0/3] FUSE: Implement atomic lookup + open/create
To:     Vivek Goyal <vgoyal@redhat.com>
Cc:     Miklos Szeredi <miklos@szeredi.hu>, linux-fsdevel@vger.kernel.org,
        fuse-devel <fuse-devel@lists.sourceforge.net>,
        linux-kernel@vger.kernel.org, Bernd Schubert <bschubert@ddn.com>
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On Thu, May 5, 2022 at 12:48 AM Vivek Goyal <vgoyal@redhat.com> wrote:
>
> On Mon, May 02, 2022 at 03:55:18PM +0530, Dharmendra Singh wrote:
> > In FUSE, as of now, uncached lookups are expensive over the wire.
> > E.g additional latencies and stressing (meta data) servers from
> > thousands of clients. These lookup calls possibly can be avoided
> > in some cases. Incoming three patches address this issue.
>
> BTW, these patches are designed to improve performance by cutting down
> on number of fuse commands sent. Are there any performance numbers
> which demonstrate what kind of improvement you are seeing.
>
> Say, If I do kernel build, is the performance improvement observable?

Here are the numbers I took last time. These were taken on tmpfs to
actually see the effect of reduced calls. On local file systems it
might not be that much visible. But we have observed that on systems
where we have thousands of clients hammering the metadata servers, it
helps a lot (We did not take numbers yet as  we are required to change
a lot of our client code but would be doing it later on).

Note that for a change in performance number due to the new version of
these patches, we have just refactored the code and functionality has
remained the same since then.

here is the link to the performance numbers
https://lore.kernel.org/linux-fsdevel/20220322121212.5087-1-dharamhans87@gmail.com/