linux-kernel - Re: [PATCH v3 33/33] Reimplement IDR and IDA using the radix tree

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: <20161206124453.3d3ce26a1526fedd70988ab8@linux-foundation.org>
Date:   Tue, 6 Dec 2016 12:44:53 -0800
From:   Andrew Morton <akpm@...ux-foundation.org>
To:     Matthew Wilcox <mawilcox@...uxonhyperv.com>
Cc:     linux-kernel@...r.kernel.org,
        Konstantin Khlebnikov <koct9i@...il.com>,
        Ross Zwisler <ross.zwisler@...ux.intel.com>,
        Matthew Wilcox <willy@...ux.intel.com>, linux-mm@...ck.org,
        linux-fsdevel@...r.kernel.org,
        "Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
        Matthew Wilcox <willy@...radead.org>
Subject: Re: [PATCH v3 33/33] Reimplement IDR and IDA using the radix tree

On Mon, 28 Nov 2016 13:50:37 -0800 Matthew Wilcox <mawilcox@...uxonhyperv.com> wrote:

> The IDR is very similar to the radix tree.  It has some functionality
> that the radix tree did not have (alloc next free, cyclic allocation,
> a callback-based for_each, destroy tree), which is readily implementable
> on top of the radix tree.  A few small changes were needed in order to
> use a tag to represent nodes with free space below them.
> 
> The IDA is reimplemented as a client of the newly enhanced radix tree.
> As in the current implementation, it uses a bitmap at the last level of
> the tree.
> 
> Signed-off-by: Matthew Wilcox <willy@...radead.org>
> ---
>  include/linux/idr.h                     |  132 ++--
>  include/linux/radix-tree.h              |    5 +-
>  init/main.c                             |    3 +-
>  lib/idr.c                               | 1078 -------------------------------
>  lib/radix-tree.c                        |  632 ++++++++++++++++--

hm.  It's just a cosmetic issue, but perhaps the idr
wrappers-around-radix-tree code should be in a different .c file.



Before:

akpm3:/usr/src/25> size lib/idr.o lib/radix-tree.o  
   text    data     bss     dec     hex filename
   6566      89      16    6671    1a0f lib/idr.o
  11811     117       8   11936    2ea0 lib/radix-tree.o

After:

   text    data     bss     dec     hex filename
  14151     118       8   14277    37c5 lib/radix-tree.o


So 4500 bytes saved.  Decent.