From: Sasha Levin <levinsasha928@gmail.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: torvalds@linux-foundation.org, tj@kernel.org,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, paul.gortmaker@windriver.com,
davem@davemloft.net, rostedt@goodmis.org, mingo@elte.hu,
aarcange@redhat.com, ericvh@gmail.com, netdev@vger.kernel.org,
josh@joshtriplett.org, eric.dumazet@gmail.com,
mathieu.desnoyers@efficios.com, axboe@kernel.dk, agk@redhat.com,
dm-devel@redhat.com, neilb@suse.de, ccaulfie@redhat.com,
teigland@redhat.com, Trond.Myklebust@netapp.com,
bfields@fieldses.org, fweisbec@gmail.com, jesse@nicira.com,
venkat.x.venkatsubra@oracle.com, ejt@redhat.com,
snitzer@redhat.com, edumazet@google.com,
linux-nfs@vger.kernel.org, dev@openvswitch.org,
rds-devel@oss.oracle.com, lw@cn.fujitsu.com
Subject: Re: [PATCH 02/16] user_ns: use new hashtable implementation
Date: Wed, 15 Aug 2012 03:35:17 +0200 [thread overview]
Message-ID: <502AFCD5.6070104@gmail.com> (raw)
In-Reply-To: <87393phshy.fsf@xmission.com>
On 08/15/2012 03:08 AM, Eric W. Biederman wrote:
>> I can offer the following: I'll write a small module that will hash 1...10000
>> > into a hashtable which uses 7 bits (just like user_ns) and post the distribution
>> > we'll get.
> That won't hurt. I think 1-100 then 1000-1100 may actually be more
> representative. Not that I would mind seeing the larger range.
> Especially since I am in the process of encouraging the use of more
> uids.
>
Alrighty, the results are in (numbers are objects in bucket):
For the 0...10000 range:
Average: 78.125
Std dev: 1.4197704151
Min: 75
Max: 80
For the 1...100 range:
Average: 0.78125
Std dev: 0.5164613088
Min: 0
Max: 2
For the 1000...1100 range:
Average: 0.7890625
Std dev: 0.4964812206
Min: 0
Max: 2
Looks like hash_32 is pretty good with small numbers.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2012-08-15 1:35 UTC|newest]
Thread overview: 31+ 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 02/16] user_ns: use new " Sasha Levin
2012-08-14 23:52 ` Eric W. Biederman
[not found] ` <87txw5hw0s.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2012-08-15 0:47 ` Sasha Levin
[not found] ` <502AF184.4010907-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2012-08-15 1:08 ` Eric W. Biederman
2012-08-15 1:35 ` Sasha Levin [this message]
[not found] ` <502AFCD5.6070104-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2012-08-15 3:13 ` Eric W. Biederman
2012-08-15 3:31 ` Mathieu Desnoyers
2012-08-15 13:40 ` Sasha Levin
[not found] ` <87obmchmpu.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2012-08-15 8:46 ` David Laight
[not found] ` <AE90C24D6B3A694183C094C60CF0A2F6026B6FB5-CgBM+Bx2aUAnGFn1LkZF6NBPR1lH4CV8@public.gmane.org>
2012-08-16 14:28 ` Mathieu Desnoyers
2012-08-14 16:24 ` [PATCH 03/16] mm,ksm: " Sasha Levin
2012-08-14 16:24 ` [PATCH 07/16] net,9p: " Sasha Levin
[not found] ` <1344961490-4068-1-git-send-email-levinsasha928-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2012-08-14 16:24 ` [PATCH 01/16] hashtable: introduce a small and naive hashtable Sasha Levin
[not found] ` <1344961490-4068-2-git-send-email-levinsasha928-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2012-08-14 23:25 ` NeilBrown
[not found] ` <20120815092523.00a909ef-wvvUuzkyo1EYVZTmpyfIwg@public.gmane.org>
2012-08-15 0:24 ` Sasha Levin
2012-08-15 0:28 ` Tejun Heo
2012-08-14 16:24 ` [PATCH 04/16] workqueue: use new hashtable implementation 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 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 15/16] openvswitch: " Sasha Levin
2012-08-14 16:24 ` [PATCH 16/16] tracing output: " Sasha Levin
2012-08-14 16:24 ` [PATCH 14/16] net,rds: " 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
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=502AFCD5.6070104@gmail.com \
--to=levinsasha928@gmail.com \
--cc=Trond.Myklebust@netapp.com \
--cc=aarcange@redhat.com \
--cc=agk@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=axboe@kernel.dk \
--cc=bfields@fieldses.org \
--cc=ccaulfie@redhat.com \
--cc=davem@davemloft.net \
--cc=dev@openvswitch.org \
--cc=dm-devel@redhat.com \
--cc=ebiederm@xmission.com \
--cc=edumazet@google.com \
--cc=ejt@redhat.com \
--cc=eric.dumazet@gmail.com \
--cc=ericvh@gmail.com \
--cc=fweisbec@gmail.com \
--cc=jesse@nicira.com \
--cc=josh@joshtriplett.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-nfs@vger.kernel.org \
--cc=lw@cn.fujitsu.com \
--cc=mathieu.desnoyers@efficios.com \
--cc=mingo@elte.hu \
--cc=neilb@suse.de \
--cc=netdev@vger.kernel.org \
--cc=paul.gortmaker@windriver.com \
--cc=rds-devel@oss.oracle.com \
--cc=rostedt@goodmis.org \
--cc=snitzer@redhat.com \
--cc=teigland@redhat.com \
--cc=tj@kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=venkat.x.venkatsubra@oracle.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;
as well as URLs for NNTP newsgroup(s).