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	 76aed95319
			
		
	
	
		76aed95319
		
	
	
	
	
		
			
			The goal is to break RTNL down into per-netns mutex. This patch adds per-netns mutex and its helper functions, rtnl_net_lock() and rtnl_net_unlock(). rtnl_net_lock() acquires the global RTNL and per-netns RTNL mutex, and rtnl_net_unlock() releases them. We will replace 800+ rtnl_lock() with rtnl_net_lock() and finally removes rtnl_lock() in rtnl_net_lock(). When we need to nest per-netns RTNL mutex, we will use __rtnl_net_lock(), and its locking order is defined by rtnl_net_lock_cmp_fn() as follows: 1. init_net is first 2. netns address ascending order Note that the conversion will be done under CONFIG_DEBUG_NET_SMALL_RTNL with LOCKDEP so that we can carefully add the extra mutex without slowing down RTNL operations during conversion. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
		
			
				
	
	
		
			41 lines
		
	
	
	
		
			1.3 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
			
		
		
	
	
			41 lines
		
	
	
	
		
			1.3 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
| # SPDX-License-Identifier: GPL-2.0-only
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| 
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| config NET_DEV_REFCNT_TRACKER
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| 	bool "Enable net device refcount tracking"
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| 	depends on DEBUG_KERNEL && STACKTRACE_SUPPORT && NET
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| 	select REF_TRACKER
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| 	default n
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| 	help
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| 	  Enable debugging feature to track device references.
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| 	  This adds memory and cpu costs.
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| 
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| config NET_NS_REFCNT_TRACKER
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| 	bool "Enable networking namespace refcount tracking"
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| 	depends on DEBUG_KERNEL && STACKTRACE_SUPPORT && NET
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| 	select REF_TRACKER
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| 	default n
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| 	help
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| 	  Enable debugging feature to track netns references.
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| 	  This adds memory and cpu costs.
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| 
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| config DEBUG_NET
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| 	bool "Add generic networking debug"
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| 	depends on DEBUG_KERNEL && NET
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| 	help
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| 	  Enable extra sanity checks in networking.
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| 	  This is mostly used by fuzzers, but is safe to select.
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| 
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| config DEBUG_NET_SMALL_RTNL
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| 	bool "Add extra per-netns mutex inside RTNL"
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| 	depends on DEBUG_KERNEL && NET && LOCK_DEBUGGING_SUPPORT
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| 	select PROVE_LOCKING
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| 	default n
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| 	help
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| 	  rtnl_lock() is being replaced with rtnl_net_lock() that
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| 	  acquires the global RTNL and a small per-netns RTNL mutex.
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| 
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| 	  During the conversion, rtnl_net_lock() just adds an extra
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| 	  mutex in every RTNL scope and slows down the operations.
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| 
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| 	  Once the conversion completes, rtnl_lock() will be removed
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| 	  and rtnetlink will gain per-netns scalability.
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