lkml.org 
[lkml]   [2012]   [Aug]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 02/16] user_ns: use new hashtable implementation
    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.


    \
     
     \ /
      Last update: 2012-08-15 04:22    [W:3.026 / U:0.152 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site