25 lines
		
	
	
		
			1.0 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			25 lines
		
	
	
		
			1.0 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
What:		/sys/kernel/mm/numa/
 | 
						|
Date:		June 2021
 | 
						|
Contact:	Linux memory management mailing list <linux-mm@kvack.org>
 | 
						|
Description:	Interface for NUMA
 | 
						|
 | 
						|
What:		/sys/kernel/mm/numa/demotion_enabled
 | 
						|
Date:		June 2021
 | 
						|
Contact:	Linux memory management mailing list <linux-mm@kvack.org>
 | 
						|
Description:	Enable/disable demoting pages during reclaim
 | 
						|
 | 
						|
		Page migration during reclaim is intended for systems
 | 
						|
		with tiered memory configurations.  These systems have
 | 
						|
		multiple types of memory with varied performance
 | 
						|
		characteristics instead of plain NUMA systems where
 | 
						|
		the same kind of memory is found at varied distances.
 | 
						|
		Allowing page migration during reclaim enables these
 | 
						|
		systems to migrate pages from fast tiers to slow tiers
 | 
						|
		when the fast tier is under pressure.  This migration
 | 
						|
		is performed before swap.  It may move data to a NUMA
 | 
						|
		node that does not fall into the cpuset of the
 | 
						|
		allocating process which might be construed to violate
 | 
						|
		the guarantees of cpusets.  This should not be enabled
 | 
						|
		on systems which need strict cpuset location
 | 
						|
		guarantees.
 |