From: "H. Peter Anvin" <hpa@zytor.com>
To: David Howells <dhowells@redhat.com>
Cc: torvalds@osdl.org, akpm@osdl.org, benh@kernel.crashing.org,
linux-kernel@vger.kernel.org, johannes@sipsolutions.net
Subject: Re: [PATCH] Fix get_order() [try #2]
Date: Tue, 06 Mar 2007 10:51:27 -0800 [thread overview]
Message-ID: <45EDB82F.8030803@zytor.com> (raw)
In-Reply-To: <11476.1173206866@redhat.com>
David Howells wrote:
> H. Peter Anvin <hpa@zytor.com> wrote:
>
>> Why not just make it ((n) < 1 ? 0 : ...) and make it well-defined for
>> n == 0?
>
> Because log2(0) is -INF or mathematically undefined or something isn't it?
Yes, but it's a *rounding up* function. In this case, it makes sense to
round up 0 to 1. This is, in fact, a common way to handle requests for
zero-byte allocation in order to be able to return a unique address for
each one, so it's not a spurious thing.
-hpa
next prev parent reply other threads:[~2007-03-06 18:53 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-06 18:34 [PATCH] Fix get_order() [try #2] David Howells
2007-03-06 18:37 ` H. Peter Anvin
2007-03-06 18:41 ` David Howells
2007-03-06 18:39 ` H. Peter Anvin
2007-03-06 18:47 ` David Howells
2007-03-06 18:51 ` H. Peter Anvin [this message]
2007-03-06 19:42 ` Alexey Dobriyan
2007-03-06 20:01 ` David Howells
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=45EDB82F.8030803@zytor.com \
--to=hpa@zytor.com \
--cc=akpm@osdl.org \
--cc=benh@kernel.crashing.org \
--cc=dhowells@redhat.com \
--cc=johannes@sipsolutions.net \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@osdl.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.