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From: "Theodore Tso" <tytso@mit.edu>
To: Mario Lohajner <mario_lohajner@rocketmail.com>
Cc: Andreas Dilger <adilger@dilger.ca>,
	libaokun1@huawei.com, adilger.kernel@dilger.ca,
	linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
	yangerkun@huawei.com, libaokun9@gmail.com
Subject: Re: [PATCH] ext4: rralloc - (former rotalloc) improved round-robin allocation policy
Date: Mon, 2 Mar 2026 20:33:09 -0500	[thread overview]
Message-ID: <20260303013309.GB6520@macsyma-wired.lan> (raw)
In-Reply-To: <c156caec-e2c8-4b85-a135-0adecb56a859@rocketmail.com>

On Mon, Mar 02, 2026 at 09:04:44PM +0100, Mario Lohajner wrote:
> RRALLOC spreads allocation starting points across block groups to avoid
> repeated concentration under parallel load.

There are already other ways in which we spread allocations across
block groups.  You need to tell explain a specific workload where this
actually makes a difference.

Also note that in most use cases, files are written once, and read
multiple times.  So spreading blocks across different block groups is
can often be actively harmful.

> In high-concurrency testing, performance is consistently comparable to
> or occasionally better than the regular allocator. No regressions have
> been observed across tested configurations.

No regressions, and only "occasionally better" not enough of a justifiation.

What is your real life workload which is motivating your efforts?

     	     	       		      	 - Ted

  reply	other threads:[~2026-03-03  1:33 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20260225201520.220071-1-mario_lohajner.ref@rocketmail.com>
2026-02-25 20:15 ` [PATCH] ext4: rralloc - (former rotalloc) improved round-robin allocation policy Mario Lohajner
2026-02-25 23:49   ` Andreas Dilger
2026-02-26  2:48     ` Theodore Tso
2026-02-26 21:50       ` Mario Lohajner
2026-02-27  1:12         ` Theodore Tso
2026-02-27 14:46           ` Mario Lohajner
2026-02-27 16:43             ` Theodore Tso
2026-03-02 20:04               ` Mario Lohajner
2026-03-03  1:33                 ` Theodore Tso [this message]
2026-03-03 13:28                   ` Mario Lohajner
2026-03-05  2:47                     ` Theodore Tso

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