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Date:   Mon, 7 Mar 2022 21:25:20 -0800
From:   Jakub Kicinski <kuba@kernel.org>
To:     "dust.li" <dust.li@linux.alibaba.com>
Cc:     kernel test robot <lkp@intel.com>, kbuild-all@lists.01.org,
        linux-kernel@vger.kernel.org
Subject: Re: [saeed:net-next 154/185] net/smc/smc_sysctl.h:23:16: warning:
 no previous prototype for 'smc_sysctl_net_init'
Message-ID: <20220307212520.176fce24@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
In-Reply-To: <20220308051655.GF35207@linux.alibaba.com>
References: <202203081012.KgONXWsS-lkp@intel.com>
        <20220308051655.GF35207@linux.alibaba.com>
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On Tue, 8 Mar 2022 13:16:55 +0800 dust.li wrote:
> >vim +/smc_sysctl_net_init +23 net/smc/smc_sysctl.h
> >
> >    22	  
> >  > 23	int __net_init smc_sysctl_net_init(struct net *net)  
> >    24	{
> >    25		net->smc.sysctl_autocorking_size = SMC_AUTOCORKING_DEFAULT_SIZE;
> >    26		return 0;
> >    27	}
> >    28	  
> >  > 29	void __net_exit smc_sysctl_net_exit(struct net *net) { }  
> >    30	  
> 
> Hi Jakub:
> 
> Sorry to bother again on this !
> Looks like we still need to add 'static inline' or add an extra
> declaration for these 2 functions if we want to get rid of these warnings.
> What do you think ?

Sorry my comment was pretty unclear an unnecessary.

I meant that you don't need the __net_init annotation, it still 
needs to be a static inline. So this is what I meant:

diff --git a/net/smc/smc_sysctl.h b/net/smc/smc_sysctl.h
index 1d554300604d..0becc11bd2f4 100644
--- a/net/smc/smc_sysctl.h
+++ b/net/smc/smc_sysctl.h
@@ -20,13 +20,13 @@ void __net_exit smc_sysctl_net_exit(struct net *net);
 
 #else
 
-int __net_init smc_sysctl_net_init(struct net *net)
+static inline int smc_sysctl_net_init(struct net *net)
 {
        net->smc.sysctl_autocorking_size = SMC_AUTOCORKING_DEFAULT_SIZE;
        return 0;
 }
 
-void __net_exit smc_sysctl_net_exit(struct net *net) { }
+static inline void smc_sysctl_net_exit(struct net *net) { }
 
 #endif /* CONFIG_SYSCTL */


But really it does not matter if the __net_init / exit is there, 
so this works too:

diff --git a/net/smc/smc_sysctl.h b/net/smc/smc_sysctl.h
index 1d554300604d..6979e7173669 100644
--- a/net/smc/smc_sysctl.h
+++ b/net/smc/smc_sysctl.h
@@ -20,13 +20,13 @@ void __net_exit smc_sysctl_net_exit(struct net *net);
 
 #else
 
-int __net_init smc_sysctl_net_init(struct net *net)
+static inline int __net_init smc_sysctl_net_init(struct net *net)
 {
        net->smc.sysctl_autocorking_size = SMC_AUTOCORKING_DEFAULT_SIZE;
        return 0;
 }
 
-void __net_exit smc_sysctl_net_exit(struct net *net) { }
+static inline void __net_exit smc_sysctl_net_exit(struct net *net) { }
 
 #endif /* CONFIG_SYSCTL */