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From: Patrick McHardy <kaber@trash.net>
To: Jan Engelhardt <jengelh@computergmbh.de>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	"David Miller" <davem@davemloft.net>,
	"Arnaldo Carvalho de Melo" <acme@redhat.com>
Subject: Re: [RFC PATCH 3/8] [NET]: uninline dev_alloc_skb, de-bloats a lot
Date: Wed, 20 Feb 2008 17:27:39 +0100	[thread overview]
Message-ID: <47BC54FB.2050508@trash.net> (raw)
In-Reply-To: <Pine.LNX.4.64.0802201651580.26109@fbirervta.pbzchgretzou.qr>

Jan Engelhardt wrote:
> On Feb 20 2008 15:47, Ilpo Järvinen wrote:
>> -23668  392 funcs, 104 +, 23772 -, diff: -23668 --- dev_alloc_skb
>>
>> -static inline struct sk_buff *dev_alloc_skb(unsigned int length)
>> -{
>> -	return __dev_alloc_skb(length, GFP_ATOMIC);
>> -}
>> +extern struct sk_buff *dev_alloc_skb(unsigned int length);
> 
> Striking. How can this even happen? A callsite which calls
> 
> 	dev_alloc_skb(n)
> 
> is just equivalent to
> 
> 	__dev_alloc_skb(n, GFP_ATOMIC);
> 
> which means there's like 4 (or 8 if it's long) bytes more on the
> stack. For a worst case, count in another 8 bytes for push and pop or mov on
> the stack. But that still does not add up to 23 kb.


__dev_alloc_skb() is also an inline function which performs
some extra work. Which raises the question - if dev_alloc_skb()
is uninlined, shouldn't __dev_alloc_skb() be uninline as well?

  reply	other threads:[~2008-02-20 16:38 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-20 13:47 [RFC PATCH 0/8]: uninline & uninline Ilpo Järvinen
2008-02-20 13:47 ` [RFC PATCH 1/8] [NET]: uninline skb_put, de-bloats a lot Ilpo Järvinen
2008-02-20 13:47   ` [RFC PATCH 2/8] [NET]: uninline skb_pull, " Ilpo Järvinen
2008-02-20 13:47     ` [RFC PATCH 3/8] [NET]: uninline dev_alloc_skb, " Ilpo Järvinen
2008-02-20 13:47       ` [RFC PATCH 4/8] [NET]: uninline skb_push, " Ilpo Järvinen
2008-02-20 13:47         ` [RFC PATCH 5/8] [NET]: uninline dst_release Ilpo Järvinen
2008-02-20 13:47           ` [RFC PATCH 6/8] [NET]: uninline skb_trim, de-bloats Ilpo Järvinen
2008-02-20 13:47             ` [RFC PATCH 7/8] [SCTP]: uninline sctp_add_cmd_sf Ilpo Järvinen
2008-02-20 13:47               ` [RFC PATCH 8/8] Jhash in too big for inlining, move under lib/ Ilpo Järvinen
2008-02-23  8:02                 ` Andrew Morton
2008-02-23 10:05                   ` Ilpo Järvinen
2008-02-23 18:21                     ` Andrew Morton
2008-02-23 13:06                   ` Andi Kleen
2008-02-20 22:16               ` [RFC PATCH 7/8] [SCTP]: uninline sctp_add_cmd_sf Vlad Yasevich
2008-02-20 22:34                 ` Ilpo Järvinen
2008-02-21 15:27                   ` Vlad Yasevich
2008-02-20 16:19       ` [RFC PATCH 3/8] [NET]: uninline dev_alloc_skb, de-bloats a lot Jan Engelhardt
2008-02-20 16:27         ` Patrick McHardy [this message]
2008-02-20 16:30           ` Jan Engelhardt
2008-02-20 22:18             ` Ilpo Järvinen
2008-03-12 15:27               ` Ilpo Järvinen
2008-02-20 13:54   ` [RFC PATCH 1/8] [NET]: uninline skb_put, " Patrick McHardy
2008-02-20 13:57   ` Eric Dumazet
2008-02-23  8:02 ` [RFC PATCH 0/8]: uninline & uninline Andrew Morton
2008-02-23 10:11   ` Ilpo Järvinen
2008-02-23 13:15   ` Andi Kleen
2008-02-23 18:06     ` Ilpo Järvinen
2008-02-23 18:55     ` Andrew Morton
2008-02-23 19:58       ` Hua Zhong
2008-02-23 21:02         ` Andi Kleen
2008-02-27 19:08       ` profile-likely patch (was " Valdis.Kletnieks

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