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From: santosh shilimkar <santosh.shilimkar@oracle.com>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	ssantosh@kernel.org
Subject: Re: [PATCH 05/15] RDS: increase size of hash-table to 8K
Date: Mon, 21 Sep 2015 16:55:25 -0700	[thread overview]
Message-ID: <560098ED.7@oracle.com> (raw)
In-Reply-To: <20150921.160527.1218605543469993281.davem@davemloft.net>

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

  reply	other threads:[~2015-09-21 23:55 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-19 23:04 [PATCH 00/15] RDS: connection scalability and performance improvements Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 01/15] RDS: use kfree_rcu in rds_ib_remove_ipaddr Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 02/15] RDS: make socket bind/release locking scheme simple and more efficient Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 03/15] RDS: fix rds_sock reference bug while doing bind Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 04/15] RDS: Use per-bucket rw lock for bind hash-table Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 05/15] RDS: increase size of hash-table to 8K Santosh Shilimkar
2015-09-21  8:31   ` David Laight
2015-09-21 15:52     ` santosh shilimkar
2015-09-21 23:05   ` David Miller
2015-09-21 23:55     ` santosh shilimkar [this message]
2015-09-23 18:06       ` santosh shilimkar
2015-09-19 23:04 ` [PATCH 06/15] RDS: defer the over_batch work to send worker Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 07/15] RDS: use rds_send_xmit() state instead of RDS_LL_SEND_FULL Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 08/15] RDS: ack more receive completions to improve performance Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 09/15] RDS: split send completion handling and do batch ack Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 10/15] RDS: handle rds_ibdev release case instead of crashing the kernel Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 11/15] RDS: fix the rds_ib_fmr_wq kick call Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 12/15] RDS: use already available pool handle from ibmr Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 13/15] RDS: mark rds_ib_fmr_wq static Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 14/15] RDS: use max_mr from HCA caps than max_fmr Santosh Shilimkar
2015-09-19 23:04 ` [PATCH 15/15] RDS: split mr pool to improve 8K messages performance Santosh Shilimkar
2015-09-20  8:37 ` [PATCH 00/15] RDS: connection scalability and performance improvements Sagi Grimberg
     [not found]   ` <55FE7060.6010205-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
2015-09-21 16:02     ` santosh shilimkar

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