54d0e963f6
Allow user space to install a matchall classifier with sample action on egress. This is only supported on Spectrum-2 onwards, so Spectrum-1 will continue to return an error. Programming the hardware to sample on egress is identical to ingress sampling with the sole change of using a different sampling trigger. Upon receiving a sampled packet, the sampling trigger (ingress vs. egress) will be encoded in the mirroring reason in the Completion Queue Element (CQE). The mirroring reason is used to lookup the sampling parameters (e.g., psample group) which are passed to the psample module. Note that locally generated packets that are sampled are simply consumed. This is done for several reasons. First, such packets do not have an ingress netdev given that their Rx local port is the CPU port. This breaks several basic assumptions. Second, sampling using the same interface (tc), but with flower classifier will not result in locally generated packets being sampled given that such packets are not subject to the policy engine. Third, realistically, this is not a big deal given that the vast majority of the packets being transmitted through the port are not locally generated packets. Fourth, if such packets do need to be sampled, they can be sampled with a 'skip_hw' filter and reported to the same sampling group as the data path packets. The software sampling rate can also be adjusted to fit the rate of the locally generated packets which is much lower than the rate of the data path traffic. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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.