mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-04-29 14:05:05 -04:00
b7e07bbd48
When a priority is marked as lossless using DCB PFC, or when pause frames are enabled on a port, mlxsw adds to port buffers an extra space to cover the traffic that will arrive between the time that a pause or PFC frame is emitted, and the time traffic actually stops. This is called the delay. The concept is the same in PFC and pause, however the way the extra buffer space is calculated differs. In this patch, unify this handling. Delay is to be measured in bytes of extra space, and will not include MTU. PFC handler sets the delay directly from the parameter it gets through the DCB interface. To convert pause handler, move MLXSW_SP_PAUSE_DELAY to ethtool module, convert to bytes, and reduce it by maximum MTU, and divide by two. Then it has the same meaning as the delay_bytes set by the PFC handler. Keep the delay_bytes value in struct mlxsw_sp_hdroom introduced in the previous patch. Change PFC and pause handlers to store the new delay value there and have __mlxsw_sp_port_headroom_set() take it from there. Instead of mlxsw_sp_pfc_delay_get() and mlxsw_sp_pg_buf_delay_get(), introduce mlxsw_sp_hdroom_buf_delay_get() to calculate the delay provision. Drop the unnecessary MLXSW_SP_CELL_FACTOR, and instead add an explanatory comment describing the formula used. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: Ido Schimmel <idosch@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.