From: Timofey Titovets <nefelim4ag@gmail.com>
To: Diego Calleja <diegocg@gmail.com>
Cc: linux-btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: [PATCH v5 4/6] Btrfs: heuristic add detection of zeroed sample
Date: Wed, 23 Aug 2017 23:03:03 +0300 [thread overview]
Message-ID: <CAGqmi77RHjeJfwdqhRDs5ityswKfPLF2Og-GEbZKjbr0TfKikw@mail.gmail.com> (raw)
In-Reply-To: <4756671.4QeJesEyyX@archlinux>
2017-08-23 20:55 GMT+03:00 Diego Calleja <diegocg@gmail.com>:
> El miércoles, 23 de agosto de 2017 2:26:48 (CEST) Timofey Titovets escribió:
>> + for (i = 0; i < workspace->sample_size; i += sizeof(zero)) {
>> + if (memcmp(&workspace->sample[i], &zero, sizeof(zero)))
>> + return false;
>
> Instead of just checking for 0, wouldn't it be a better idea to check
> for any kind of repetitions?
>
> As in, iterate over the sample and memcmp() each part of sample with
> the previous one. The cost would be the same, and it would detect not
> just zeros, but any kind of repeated data. Is there any reason I'm
> missing for not doing this?
Thank you, i was not think about that,
That approach seems better, i will update the patch.
--
Have a nice day,
Timofey.
next prev parent reply other threads:[~2017-08-23 20:03 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-23 0:26 [PATCH v5 0/6] Btrfs: populate heuristic with code Timofey Titovets
2017-08-23 0:26 ` [PATCH v5 1/6] Btrfs: heuristic make use compression workspaces Timofey Titovets
2017-08-23 0:26 ` [PATCH v5 2/6] Btrfs: heuristic workspace add bucket and sample items Timofey Titovets
2017-08-23 0:26 ` [PATCH v5 3/6] Btrfs: implement heuristic sampling logic Timofey Titovets
2017-08-23 0:26 ` [PATCH v5 4/6] Btrfs: heuristic add detection of zeroed sample Timofey Titovets
2017-08-23 17:55 ` Diego Calleja
2017-08-23 20:03 ` Timofey Titovets [this message]
2017-08-23 0:26 ` [PATCH v5 5/6] Btrfs: heuristic add byte set calculation Timofey Titovets
2017-08-23 0:26 ` [PATCH v5 6/6] Btrfs: heuristic add byte core " Timofey Titovets
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