public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Alexander Holler <holler@ahsoftware.de>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Mike Frysinger <vapier.adi@gmail.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/1] Implement /dev/byte (a generic byte source similiar to /dev/zero)
Date: Tue, 19 Apr 2011 11:05:10 +0200	[thread overview]
Message-ID: <4DAD5046.3030008@ahsoftware.de> (raw)
In-Reply-To: <20110419094436.0b667410@lxorguk.ukuu.org.uk>

Hello,

Am 19.04.2011 10:44, schrieb Alan Cox:
>> As for /dev/zero there are many other possible reasons to use such a
>> device, besides filling something with a value. For me it's as
>> reasonable as dev/zero, just that it offers a bit more flexibility and
>> provides another, at least for me useful, default value. Maybe
>> /dev/nzero would have been a good name too. ;)
>
> /dev/zero exists not to put \0's into files as such but because it is
> very useful to be able to map the zero page (a read only, or
> copy-on-write blank page) into programs. The mmap is the reason it is
> there.

Thanks for the explanation.

>> But I don't really care about inclusion into the kernel, it's just
>> something I had lying around (and needed only marginally work to
>> finalize as a proper patch) and I thought someone else could find it
>> usefull and I should share that here.
>
> Implementationwise I think I would have gone for allocating a new device
> and range of 256 minors - that would avoid the funky stuff setting what
> it fills with as you'd just fill with the minor number.

I thought about that too, but that would have been to easy (and static). ;)

And the usage of file descriptors was the only idea I've come up with, 
which is multitasking and multiuser aware.

Regards,

Alexander

  reply	other threads:[~2011-04-19  9:05 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-18 11:37 [PATCH 0/1] Implement /dev/byte (a generic byte source similiar to /dev/zero) Alexander Holler
2011-04-18 11:37 ` [PATCH 1/1] " Alexander Holler
2011-04-20 10:57   ` Pavel Machek
2011-04-20 18:07     ` Alexander Holler
2011-04-18 13:57 ` [PATCH 0/1] " Mike Frysinger
2011-04-19  8:34   ` Alexander Holler
2011-04-19  8:44     ` Alan Cox
2011-04-19  9:05       ` Alexander Holler [this message]
2011-04-19  9:32         ` Alexander Holler

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=4DAD5046.3030008@ahsoftware.de \
    --to=holler@ahsoftware.de \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=linux-kernel@vger.kernel.org \
    --cc=vapier.adi@gmail.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