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From: Sasha Levin <levinsasha928@gmail.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Tejun Heo <tj@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 02/16] user_ns: use new hashtable implementation
Date: Sat, 18 Aug 2012 23:52:26 +0200	[thread overview]
Message-ID: <50300E9A.1060501@gmail.com> (raw)
In-Reply-To: <87txw5hw0s.fsf@xmission.com>

On 08/15/2012 01:52 AM, Eric W. Biederman wrote:
> Sasha Levin <levinsasha928@gmail.com> writes:
>> > Switch user_ns to use the new hashtable implementation. This reduces the amount of
>> > generic unrelated code in user_ns.
> Two concerns here.
> 1) When adding a new entry you recompute the hash where previously that
>    was not done.  I believe that will slow down adding of new entries.

Since the hashtable doesn't expose the internal hashing to the user of the
hashtable it would require adding a new interface to deal with in.

I don't feel that a whole new interface to optimize out something which is very
cheap (one multiplication + shift) in this case, I'd rather avoid having a new
interface.

Is it ok with you if I leave it as is in the next version of the patch?

  parent reply	other threads:[~2012-08-18 21:51 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-14 16:24 [PATCH 00/16] generic hashtable implementation Sasha Levin
2012-08-14 16:24 ` [PATCH 01/16] hashtable: introduce a small and naive hashtable Sasha Levin
2012-08-14 23:25   ` NeilBrown
2012-08-15  0:24     ` Sasha Levin
2012-08-15  0:28       ` Tejun Heo
2012-08-14 16:24 ` [PATCH 02/16] user_ns: use new hashtable implementation Sasha Levin
2012-08-14 23:52   ` Eric W. Biederman
2012-08-15  0:47     ` Sasha Levin
2012-08-15  1:08       ` Eric W. Biederman
2012-08-15  1:35         ` Sasha Levin
2012-08-15  3:13           ` Eric W. Biederman
2012-08-15  3:31             ` Mathieu Desnoyers
2012-08-15 13:40               ` Sasha Levin
2012-08-15  8:46             ` David Laight
2012-08-16 14:28               ` Mathieu Desnoyers
2012-08-18 21:52     ` Sasha Levin [this message]
2012-08-18 22:21       ` Eric W. Biederman
2012-08-14 16:24 ` [PATCH 03/16] mm,ksm: " Sasha Levin
2012-08-14 16:24 ` [PATCH 04/16] workqueue: " Sasha Levin
2012-08-14 16:24 ` [PATCH 05/16] mm/huge_memory: " Sasha Levin
2012-08-14 16:24 ` [PATCH 06/16] tracepoint: " Sasha Levin
2012-08-14 16:24 ` [PATCH 07/16] net,9p: " Sasha Levin
2012-08-14 16:24 ` [PATCH 08/16] block,elevator: " Sasha Levin
2012-08-14 16:24 ` [PATCH 09/16] SUNRPC/cache: " Sasha Levin
2012-08-14 16:24 ` [PATCH 10/16] dlm: " Sasha Levin
2012-08-14 16:24 ` [PATCH 11/16] net,l2tp: " Sasha Levin
2012-08-14 16:24 ` [PATCH 12/16] dm: " Sasha Levin
2012-08-14 16:24 ` [PATCH 13/16] lockd: " Sasha Levin
2012-08-14 16:24 ` [PATCH 14/16] net,rds: " Sasha Levin
2012-08-14 16:24 ` [PATCH 15/16] openvswitch: " Sasha Levin
2012-08-14 16:24 ` [PATCH 16/16] tracing output: " Sasha Levin
2012-08-14 18:16 ` [PATCH 00/16] generic " J. Bruce Fields
  -- strict thread matches above, loose matches on Subject: below --
2012-08-19  0:52 [PATCH v2 " Sasha Levin
2012-08-19  0:52 ` [PATCH 02/16] user_ns: use new " Sasha Levin

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