xref: /OK3568_Linux_fs/kernel/Documentation/ABI/obsolete/sysfs-class-dax (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunWhat:           /sys/class/dax/
2*4882a593SmuzhiyunDate:           May, 2016
3*4882a593SmuzhiyunKernelVersion:  v4.7
4*4882a593SmuzhiyunContact:        linux-nvdimm@lists.01.org
5*4882a593SmuzhiyunDescription:	Device DAX is the device-centric analogue of Filesystem
6*4882a593Smuzhiyun		DAX (CONFIG_FS_DAX).  It allows memory ranges to be
7*4882a593Smuzhiyun		allocated and mapped without need of an intervening file
8*4882a593Smuzhiyun		system.  Device DAX is strict, precise and predictable.
9*4882a593Smuzhiyun		Specifically this interface:
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun		1. Guarantees fault granularity with respect to a given
12*4882a593Smuzhiyun		   page size (pte, pmd, or pud) set at configuration time.
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun		2. Enforces deterministic behavior by being strict about
15*4882a593Smuzhiyun		   what fault scenarios are supported.
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun		The /sys/class/dax/ interface enumerates all the
18*4882a593Smuzhiyun		device-dax instances in the system. The ABI is
19*4882a593Smuzhiyun		deprecated and will be removed after 2020. It is
20*4882a593Smuzhiyun		replaced with the DAX bus interface /sys/bus/dax/ where
21*4882a593Smuzhiyun		device-dax instances can be found under
22*4882a593Smuzhiyun		/sys/bus/dax/devices/
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