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Date:   Mon, 10 Feb 2020 20:08:08 +0000
From:   Luis Chamberlain <mcgrof@kernel.org>
To:     Davidlohr Bueso <dave@stgolabs.net>
Cc:     akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
        broonie@kernel.org, alex.williamson@redhat.com,
        keescook@chromium.org, yzaikin@google.com,
        linux-fsdevel@vger.kernel.org, Davidlohr Bueso <dbueso@suse.de>
Subject: Re: [PATCH 2/5] proc/sysctl: optimize proc_sys_readdir
Message-ID: <20200210200808.GN11244@42.do-not-panic.com>
References: <20200207180305.11092-1-dave@stgolabs.net>
 <20200207180305.11092-3-dave@stgolabs.net>
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On Fri, Feb 07, 2020 at 10:03:02AM -0800, Davidlohr Bueso wrote:
> This patch coverts struct ctl_dir to use an llrbtree
> instead of a regular rbtree such that computing nodes for
> potential usable entries becomes a branchless O(1) operation,
> therefore optimizing first_usable_entry(). The cost are
> mainly three additional pointers: one for the root and two
> for each struct ctl_node next/prev nodes, enlarging it from
> 32 to 48 bytes on x86-64.

Acked-by: Luis Chamberlain <mcgrof@kernel.org>

  Luis