netdev - Re: [net-next 01/15] net/mlx5: DR, Add buddy allocator utilities

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20201006.074715.742357947812105732.davem@davemloft.net>
Date:   Tue, 06 Oct 2020 07:47:15 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     kliteyn@...dia.com
Cc:     saeed@...nel.org, kuba@...nel.org, netdev@...r.kernel.org,
        erezsh@...dia.com, mbloch@...dia.com, saeedm@...dia.com
Subject: Re: [net-next 01/15] net/mlx5: DR, Add buddy allocator utilities

From: Yevgeny Kliteynik <kliteyn@...dia.com>
Date: Tue, 6 Oct 2020 16:02:24 +0300

> Buddy allocator allocates blocks of different sizes, so when it
> scans the bits array, the allocator looks for free *area* of at
> least the required size.
> Can't store this info in a 'lowest set bit' counter.

If you make it per-order, why not?

> Furthermore, when buddy allocator scans for such areas, it
> takes into consideration blocks alignment as required by HW,
> which can't be stored in an external counter.

That's why you scan the bits, which you have to do anyways.

I'm kinda disappointed in how this discussion is going, to be honest.