81adb86334
>From the NVMe 1.4 spec: NSFEAT bit 4 if set to 1: indicates that the fields NPWG, NPWA, NPDG, NPDA, and NOWS are defined for this namespace and should be used by the host for I/O optimization; [ ... ] Namespace Preferred Write Granularity (NPWG): This field indicates the smallest recommended write granularity in logical blocks for this namespace. This is a 0's based value. The size indicated should be less than or equal to Maximum Data Transfer Size (MDTS) that is specified in units of minimum memory page size. The value of this field may change if the namespace is reformatted. The size should be a multiple of Namespace Preferred Write Alignment (NPWA). Refer to section 8.25 for how this field is utilized to improve performance and endurance. [ ... ] Each Write, Write Uncorrectable, or Write Zeroes commands should address a multiple of Namespace Preferred Write Granularity (NPWG) (refer to Figure 245) and Stream Write Size (SWS) (refer to Figure 515) logical blocks (as expressed in the NLB field), and the SLBA field of the command should be aligned to Namespace Preferred Write Alignment (NPWA) (refer to Figure 245) for best performance. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.