Messages in this thread | | | Date | Tue, 24 Jul 2007 00:28:36 +0400 | From | Alexey Dobriyan <> | Subject | Re: CTL_UNNUMBERED (Re: [PATCH] 9p: Don't use binary sysctl numbers.) |
| |
On Sat, Jul 21, 2007 at 04:36:03PM -0600, Eric W. Biederman wrote: > Alexey Dobriyan <adobriyan@gmail.com> writes: > > That's separate patch but CTL_UNNUMBERED must die, because it's totally > > unneeded. If you don't want sysctl(2) interface just SKIP ->ctl_name > > initialization and save one line for something useful.
[9p and .ctl_name]
> Now to the issue of using CTL_UNNUMBERED versus knowing that the magic > value is zero and we can just leave it uninitialized. I don't much > care but given how often people who are not actively watching this > mess up I tend to prefer the explicit value.
mmm, from my own experience the quickest way to add sysctl to kernel is to _copy_ from other place and tweak variable name and string itself. I'm sure that's what evebody is doing.
And once you're copy-pasting, existence of CTL_UNNUMBERED or absence of it doesn't matter. Propagating of CTL_UNNUMBERED or empty .ctl_name depends entirely on the place from where you're copy-pasting.
And since it doesn't matter, we'd better save one line :)
> It is a practical > question of how do we get the word out that we should not expand the > binary interface anymore.
Article on LWN, scary comment near struct ctl_table::ctl_name, tree-wide removal .ctl_name initializers, periodic grepping of -mm and -rc diffs. I promise to grep next -mm patch and submit CTL_UNNUMBERED removal :)
> The only really practical way I can see us doing better then we are > today is to have a separate tree that maps binary numbers into ascii > strings and so we remove the ctl_name field entirely from ctl_table.
Not sure how to do this cleanly and without flag-day. And it's additional code.
> That way people attempting to assign binary numbers using old > conventions will have code that doesn't even compile, and the > developers themselves are more likely to spot the problem.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |