mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-05 18:41:58 +09:00
d862176238
Jacob Keller says: ==================== support direct read from region A long time ago when initially implementing devlink regions in ice I proposed the ability to allow reading from a region without taking a snapshot [1]. I eventually dropped this work from the original series due to size. Then I eventually lost track of submitting this follow up. This can be useful when interacting with some region that has some definitive "contents" from which snapshots are made. For example the ice driver has regions representing the contents of the device flash. If userspace wants to read the contents today, it must first take a snapshot and then read from that snapshot. This makes sense if you want to read a large portion of data or you want to be sure reads are consistently from the same recording of the flash. However if user space only wants to read a small chunk, it must first generate a snapshot of the entire contents, perform a read from the snapshot, and then delete the snapshot after reading. For such a use case, a direct read from the region makes more sense. This can be achieved by allowing the devlink region read command to work without a snapshot. Instead the portion to be read can be forwarded directly to the driver via a new .read callback. This avoids the need to read the entire region contents into memory first and avoids the software overhead of creating a snapshot and then deleting it. This series implements such behavior and hooks up the ice NVM and shadow RAM regions to allow it. [1] https://lore.kernel.org/netdev/20200130225913.1671982-1-jacob.e.keller@intel.com/ ==================== Link: https://lore.kernel.org/r/20221128203647.1198669-1-jacob.e.keller@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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.