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From: David Miller <davem@davemloft.net>
To: raghavendra.kt@linux.vnet.ibm.com
Cc: edumazet@google.com, kuznet@ms2.inr.ac.ru, jmorris@namei.org,
	yoshfuji@linux-ipv6.org, kaber@trash.net, jiri@resnulli.us,
	hannes@stressinduktion.org, tom@herbertland.com,
	azhou@nicira.com, ebiederm@xmission.com, ipm@chirality.org.uk,
	nicolas.dichtel@6wind.com, serge.hallyn@canonical.com,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	anton@au1.ibm.com, nacc@linux.vnet.ibm.com,
	srikar@linux.vnet.ibm.com
Subject: Re: [PATCH RFC V2 2/2] net: Optimize snmp stat aggregation by walking all the percpu data at once
Date: Fri, 28 Aug 2015 11:24:13 -0700 (PDT)	[thread overview]
Message-ID: <20150828.112413.424099339331017970.davem@davemloft.net> (raw)
In-Reply-To: <55E00238.10909@linux.vnet.ibm.com>

From: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Date: Fri, 28 Aug 2015 12:09:52 +0530

> On 08/28/2015 12:08 AM, David Miller wrote:
>> From: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
>> Date: Wed, 26 Aug 2015 23:07:33 +0530
>>
>>> @@ -4641,10 +4647,12 @@ static inline void __snmp6_fill_stats64(u64
>>> *stats, void __percpu *mib,
>>>   static void snmp6_fill_stats(u64 *stats, struct inet6_dev *idev, int
>>>   attrtype,
>>>   			     int bytes)
>>>   {
>>> +	u64 buff[IPSTATS_MIB_MAX] = {0,};
>>> +
 ...
> hope you wanted to know the overhead than to change the current
> patch. please let me know..

I want you to change that variable initializer to an explicit memset().

The compiler is emitting a memset() or similar _anyways_.

Not because it will have any impact at all upon performance, but because
of how it looks to people trying to read and understand the code.

  reply	other threads:[~2015-08-28 18:24 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-26 17:37 [PATCH RFC V2 0/2] Optimize the snmp stat aggregation for large cpus Raghavendra K T
2015-08-26 17:37 ` [PATCH RFC V2 1/2] net: Introduce helper functions to get the per cpu data Raghavendra K T
2015-08-26 17:37 ` [PATCH RFC V2 2/2] net: Optimize snmp stat aggregation by walking all the percpu data at once Raghavendra K T
2015-08-27 18:38   ` David Miller
2015-08-28  6:39     ` Raghavendra K T
2015-08-28 18:24       ` David Miller [this message]
2015-08-28 19:20         ` Joe Perches
2015-08-28 20:33           ` Eric Dumazet
2015-08-28 20:53             ` Joe Perches
2015-08-28 20:55               ` Eric Dumazet
2015-08-28 21:09                 ` Joe Perches
2015-08-28 21:14                   ` Eric Dumazet
2015-08-28 21:26                     ` Joe Perches
2015-08-28 22:29                       ` Eric Dumazet
2015-08-28 23:12                         ` Joe Perches
2015-08-29  0:06                           ` Eric Dumazet
2015-08-29  0:35                             ` Joe Perches
2015-08-29  0:59                               ` Eric Dumazet
2015-08-29  2:57         ` Raghavendra K T
2015-08-29  3:26           ` Eric Dumazet
2015-08-29  7:52             ` Raghavendra K T
2015-08-29  5:11           ` David Miller
2015-08-29  7:53             ` Raghavendra K T

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