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From: Miklos Szeredi <miklos@szeredi.hu>
To: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: kuznet@virtuozzo.com, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/3] fuse: Use hash table to link processing request
Date: Tue, 25 Sep 2018 11:08:55 +0200	[thread overview]
Message-ID: <CAJfpegt3ckxAUAdabXKwxgFYdP9=wVSis+G3pztWgqzXVGNFSA@mail.gmail.com> (raw)
In-Reply-To: <153666073461.19117.1958730317836145457.stgit@localhost.localdomain>

On Tue, Sep 11, 2018 at 12:12 PM, Kirill Tkhai <ktkhai@virtuozzo.com> wrote:
> We noticed the performance bottle neck in FUSE running our
> Virtuozzo storage over rdma. On some types of workload
> we observe 20% of times pent in request_find() in profiler.
> This function is iterating over long requests list, and it
> scales bad.
>
> The patch introduces hash table to reduce the number
> of iterations, we do in this function. Hash generating
> algorithm is taken from hash_add() function, while
> 512 lines table is used to store pending requests.
> This fixes problem and improves the performance.

Pushed to fuse.git#for-next with a number of small changes.   E.g. I
reduced the number of cachlines to 256 to make the hashtable size just
4k.   Was there a scientific reason for choosing 512 as the optimal
number of cache lines?

Thanks,
Miklos

  reply	other threads:[~2018-09-25 15:15 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-11 10:11 [PATCH 0/3] fuse: Solve request_find() bottleneck Kirill Tkhai
2018-09-11 10:11 ` [PATCH 1/3] fuse: Change interrupt requests allocation algorhythm Kirill Tkhai
2018-09-11 10:12 ` [PATCH 2/3] fuse: Kill fuse_req::intr_unique Kirill Tkhai
2018-09-11 10:12 ` [PATCH 3/3] fuse: Use hash table to link processing request Kirill Tkhai
2018-09-25  9:08   ` Miklos Szeredi [this message]
2018-09-25  9:35     ` Kirill Tkhai
2018-09-24 12:08 ` [PATCH 0/3] fuse: Solve request_find() bottleneck Kirill Tkhai
2018-09-24 15:04   ` Miklos Szeredi

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