linux-kernel - Re: [PATCH v3 01/17] hashtable: introduce a small and naive hashtable

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]

Date:	Fri, 24 Aug 2012 13:33:32 -0700
From:	Tejun Heo <tj@...nel.org>
To:	Sasha Levin <levinsasha928@...il.com>
Cc:	torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	paul.gortmaker@...driver.com, davem@...emloft.net,
	rostedt@...dmis.org, mingo@...e.hu, ebiederm@...ssion.com,
	aarcange@...hat.com, ericvh@...il.com, netdev@...r.kernel.org,
	josh@...htriplett.org, eric.dumazet@...il.com,
	mathieu.desnoyers@...icios.com, axboe@...nel.dk, agk@...hat.com,
	dm-devel@...hat.com, neilb@...e.de, ccaulfie@...hat.com,
	teigland@...hat.com, Trond.Myklebust@...app.com,
	bfields@...ldses.org, fweisbec@...il.com, jesse@...ira.com,
	venkat.x.venkatsubra@...cle.com, ejt@...hat.com,
	snitzer@...hat.com, edumazet@...gle.com, linux-nfs@...r.kernel.org,
	dev@...nvswitch.org, rds-devel@....oracle.com, lw@...fujitsu.com
Subject: Re: [PATCH v3 01/17] hashtable: introduce a small and naive
 hashtable

Hello, Sasha.

On Fri, Aug 24, 2012 at 10:11:55PM +0200, Sasha Levin wrote:
> > If this implementation is about the common trivial case, why not just
> > have the usual DECLARE/DEFINE_HASHTABLE() combination?
> 
> When we add the dynamic non-resizable support, how would DEFINE_HASHTABLE() look?

Hmmm?  DECLARE/DEFINE are usually for static ones.

> > I don't know.  If we stick to the static (or even !resize dymaic)
> > straight-forward hash - and we need something like that - I don't see
> > what the full encapsulation buys us other than a lot of trivial
> > wrappers.
> 
> Which macros do you consider as trivial within the current API?
> 
> Basically this entire thing could be reduced to DEFINE/DECLARE_HASHTABLE and
> get_bucket(), but it would make the life of anyone who wants a slightly
> different hashtable a hell.

Wouldn't the following be enough to get most of the benefits?

* DECLARE/DEFINE
* hash_head()
* hash_for_each_head()
* hash_add*()
* hash_for_each_possible*()

> I think that right now the only real trivial wrapper is hash_hashed(), and I
> think it's a price worth paying to have a single hashtable API instead of
> fragmenting it when more implementations come along.

I'm not objecting strongly against full encapsulation but having this
many thin wrappers makes me scratch my head.

Thanks.

-- 
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/