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Message-ID: <0724c357-1d74-47b8-85cb-bf344eb4cc52@linux.alibaba.com>
Date: Thu, 4 Apr 2024 16:46:24 +0800
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Subject: Re: [RFC PATCH net-next v5 02/11] net/smc: introduce loopback-ism for
 SMC intra-OS shortcut
To: Gerd Bayer <gbayer@linux.ibm.com>, wintera@linux.ibm.com,
 twinkler@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com,
 agordeev@linux.ibm.com, davem@davemloft.net, edumazet@google.com,
 kuba@kernel.org, pabeni@redhat.com, wenjia@linux.ibm.com, jaka@linux.ibm.com
Cc: borntraeger@linux.ibm.com, svens@linux.ibm.com,
 alibuda@linux.alibaba.com, tonylu@linux.alibaba.com,
 linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,
 netdev@vger.kernel.org
References: <20240324135522.108564-1-guwen@linux.alibaba.com>
 <20240324135522.108564-3-guwen@linux.alibaba.com>
 <a9e1cdfba05279c36b7b85f327af66cf497d42b9.camel@linux.ibm.com>
From: Wen Gu <guwen@linux.alibaba.com>
In-Reply-To: <a9e1cdfba05279c36b7b85f327af66cf497d42b9.camel@linux.ibm.com>
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On 2024/4/3 19:27, Gerd Bayer wrote:
> On Sun, 2024-03-24 at 21:55 +0800, Wen Gu wrote:
>> Configuration of this feature is managed through the config SMC_LO.
> 
> Hi Wen,
> 
> you could omit building smc_loopback.o if CONFIG_SMC_LO was not set if
> you included the following fixup-patch. I think it's cleaner to put a
> few parts of net/smc/af_smc.c under conditional compile rather than
> have most of the contents of net/smc/smc_loopback.c under #ifdef.
> 

Hi Gerd. That is a really good suggestion. It is much cleaner in this way.
I will improve it in next version. Thank you very much!

>  From 11a9cfce550f0c4df10eafdd30aa4226d4d522a8 Mon Sep 17 00:00:00 2001
> From: Gerd Bayer <gbayer@linux.ibm.com>
> Date: Wed, 3 Apr 2024 11:43:36 +0200
> Subject: [PATCH] fixup! net/smc: introduce loopback-ism for SMC intra-
> OS
>   shortcut
> 
> ---
>   net/smc/Makefile       | 5 +++--
>   net/smc/af_smc.c       | 6 ++++++
>   net/smc/smc_loopback.c | 8 --------
>   3 files changed, 9 insertions(+), 10 deletions(-)
> 
> diff --git a/net/smc/Makefile b/net/smc/Makefile
> index a8c37111abe1..3b73c9d561bb 100644
> --- a/net/smc/Makefile
> +++ b/net/smc/Makefile
> @@ -4,5 +4,6 @@ obj-$(CONFIG_SMC)	+= smc.o
>   obj-$(CONFIG_SMC_DIAG)	+= smc_diag.o
>   smc-y := af_smc.o smc_pnet.o smc_ib.o smc_clc.o smc_core.o smc_wr.o
> smc_llc.o
>   smc-y += smc_cdc.o smc_tx.o smc_rx.o smc_close.o smc_ism.o
> smc_netlink.o smc_stats.o
> -smc-y += smc_tracepoint.o smc_loopback.o
> -smc-$(CONFIG_SYSCTL) += smc_sysctl.o
> +smc-y += smc_tracepoint.o
> +smc-$(CONFIG_SMC_LO)	+= smc_loopback.o
> +smc-$(CONFIG_SYSCTL)	+= smc_sysctl.o
> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
> index fce7a5b2ce5c..bcbf600cd271 100644
> --- a/net/smc/af_smc.c
> +++ b/net/smc/af_smc.c
> @@ -3574,11 +3574,13 @@ static int __init smc_init(void)
>   		goto out_sock;
>   	}
>   
> +#if IS_ENABLED(CONFIG_SMC_LO)
>   	rc = smc_loopback_init();
>   	if (rc) {
>   		pr_err("%s: smc_loopback_init fails with %d\n",
> __func__, rc);
>   		goto out_ib;
>   	}
> +#endif
>   
>   	rc = tcp_register_ulp(&smc_ulp_ops);
>   	if (rc) {
> @@ -3590,8 +3592,10 @@ static int __init smc_init(void)
>   	return 0;
>   
>   out_lo:
> +#if IS_ENABLED(CONFIG_SMC_LO)
>   	smc_loopback_exit();
>   out_ib:
> +#endif
>   	smc_ib_unregister_client();
>   out_sock:
>   	sock_unregister(PF_SMC);
> @@ -3628,7 +3632,9 @@ static void __exit smc_exit(void)
>   	tcp_unregister_ulp(&smc_ulp_ops);
>   	sock_unregister(PF_SMC);
>   	smc_core_exit();
> +#if IS_ENABLED(CONFIG_SMC_LO)
>   	smc_loopback_exit();
> +#endif
>   	smc_ib_unregister_client();
>   	smc_ism_exit();
>   	destroy_workqueue(smc_close_wq);
> diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c
> index 994fe39930ad..8d0181635ded 100644
> --- a/net/smc/smc_loopback.c
> +++ b/net/smc/smc_loopback.c
> @@ -19,7 +19,6 @@
>   #include "smc_ism.h"
>   #include "smc_loopback.h"
>   
> -#if IS_ENABLED(CONFIG_SMC_LO)
>   #define SMC_LO_V2_CAPABLE	0x1 /* loopback-ism acts as ISMv2 */
>   #define SMC_LO_SUPPORT_NOCOPY	0x1
>   #define SMC_DMA_ADDR_INVALID	(~(dma_addr_t)0)
> @@ -442,20 +441,13 @@ static void smc_lo_dev_remove(void)
>   	smc_lo_dev_exit(lo_dev);
>   	put_device(&lo_dev->dev); /* device_initialize in
> smc_lo_dev_probe */
>   }
> -#endif
>   
>   int smc_loopback_init(void)
>   {
> -#if IS_ENABLED(CONFIG_SMC_LO)
>   	return smc_lo_dev_probe();
> -#else
> -	return 0;
> -#endif
>   }
>   
>   void smc_loopback_exit(void)
>   {
> -#if IS_ENABLED(CONFIG_SMC_LO)
>   	smc_lo_dev_remove();
> -#endif
>   }