From: Linus Torvalds <torvalds@linux-foundation.org>
To: Cedric Blancher <cedric.blancher@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>,
Matthew Wilcox <mawilcox@linuxonhyperv.com>,
Konstantin Khlebnikov <koct9i@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Linux MM <linux-mm@kvack.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Matthew Wilcox <mawilcox@microsoft.com>
Subject: Re: [PATCH 2/2] radix-tree: Fix optimisation problem
Date: Sun, 25 Sep 2016 11:04:36 -0700 [thread overview]
Message-ID: <CA+55aFzge97L-JLKZq0CTW1wtMOsnt8QzOw3b5qCMmzbKxZ5aw@mail.gmail.com> (raw)
In-Reply-To: <CALXu0UfuwGM+H0YnfSNW6O=hgcUrmws+ihHLVB=OJWOp8YCwgw@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 772 bytes --]
On Sep 25, 2016 10:59 AM, "Cedric Blancher" <cedric.blancher@gmail.com>
wrote:
> >
> > The use of "int" is perfectly valid, since it's limited by
> > RADIX_TREE_MAP_SIZE, so it's going to be a small integer.
>
> A specific data type would be wise (aka radtr_mapsz_t) to prevent a
> disaster as SystemV had early during development.
Actually, you're right that the code is shit and shouldn't use an "int"
there.
The value range is indeed just up to RADIX_TREE_MAP_SIZE, but since the
code actually can get entries that are *not* sibling entries, it could
overflow
The more I look at that particular piece of code, the less I like it. It's
buggy shit. It needs to be rewritten entirely too actually check for
sibling entries, not that ad-hoc arithmetic crap.
Linus
[-- Attachment #2: Type: text/html, Size: 1043 bytes --]
next prev parent reply other threads:[~2016-09-25 18:04 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-22 18:53 [PATCH 0/2] Fix radix_tree_lookup_slot() Matthew Wilcox
2016-09-22 18:53 ` [PATCH 1/2] radix tree test suite: Test radix_tree_replace_slot() for multiorder entries Matthew Wilcox
2016-09-22 18:53 ` [PATCH 2/2] radix-tree: Fix optimisation problem Matthew Wilcox
2016-09-22 18:09 ` Linus Torvalds
2016-09-23 20:16 ` Matthew Wilcox
2016-09-24 20:21 ` Linus Torvalds
2016-09-24 20:47 ` Linus Torvalds
2016-09-24 21:04 ` Kirill A. Shutemov
2016-09-24 22:54 ` Linus Torvalds
2016-09-26 4:26 ` Ross Zwisler
2016-09-24 8:36 ` Konstantin Khlebnikov
2016-09-24 23:35 ` Cedric Blancher
2016-09-25 0:18 ` Linus Torvalds
2016-09-25 17:59 ` Cedric Blancher
2016-09-25 18:04 ` Linus Torvalds [this message]
2016-09-25 19:04 ` Linus Torvalds
2016-09-25 19:40 ` Cedric Blancher
2016-09-25 19:56 ` Linus Torvalds
2016-09-26 21:28 ` Matthew Wilcox
2016-09-26 21:48 ` Cedric Blancher
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CA+55aFzge97L-JLKZq0CTW1wtMOsnt8QzOw3b5qCMmzbKxZ5aw@mail.gmail.com \
--to=torvalds@linux-foundation.org \
--cc=akpm@linux-foundation.org \
--cc=cedric.blancher@gmail.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=koct9i@gmail.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mawilcox@linuxonhyperv.com \
--cc=mawilcox@microsoft.com \
--cc=ross.zwisler@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox