lkml.org 
[lkml]   [2015]   [Sep]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 05/15] RDS: increase size of hash-table to 8K
From
Date
On 9/21/2015 4:05 PM, David Miller wrote:
> From: Santosh Shilimkar <santosh.shilimkar@oracle.com>
> Date: Sat, 19 Sep 2015 19:04:42 -0400
>
>> Even with per bucket locking scheme, in a massive parallel
>> system with active rds sockets which could be in excess of multiple
>> of 10K, rds_bin_lookup() workload is siginificant because of smaller
>> hashtable size.
>>
>> With some tests, it was found that we get modest but still nice
>> reduction in rds_bind_lookup with bigger bucket.
>>
>> Hashtable Baseline(1k) Delta
>> 2048: 8.28% -2.45%
>> 4096: 8.28% -4.60%
>> 8192: 8.28% -6.46%
>> 16384: 8.28% -6.75%
>>
>> Based on the data, we set 8K as the bind hash-table size.
>>
>> Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
>> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
>
> Like others I would strongly prefer that you use a dynamically sized
> hash table.
>
> Eating 8k just because a module just happened to get loaded is really
> not appropriate.
>
> And there are many other places that use such a scheme, one example is
> the AF_NETLINK socket hash table.

OK. Thanks for AF_NETLINK pointer. I will look it up.

Regards,
Santosh


\
 
 \ /
  Last update: 2015-09-22 02:01    [W:0.209 / U:0.152 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site