Commit f72588a4 authored by Jacob Keller's avatar Jacob Keller Committed by Jakub Kicinski
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ice: reduce size of queue context fields



The ice_rlan_ctx and ice_tlan_ctx structures have some fields which are
intentionally sized larger than necessary relative to the packed sizes the
data must fit into. This was done because the original ice_set_ctx()
function and its helpers did not correctly handle packing when the packed
bits straddled a byte. This is no longer the case with the use of the
<linux/packing.h> implementation.

Save some bytes in these structures by sizing the variables to the number
of bytes the actual bitpacked fields fit into.

There are a couple of gaps left in the structure, which is a result of the
fields being in the order they appear in the packed bit layout, but where
alignment forces some extra gaps. We could fix this, saving ~8 bytes from
each structure. However, these structures are not used heavily, and the
resulting savings is minimal:

$ bloat-o-meter ice-before-reorder.ko ice-after-reorder.ko
add/remove: 0/0 grow/shrink: 1/1 up/down: 26/-70 (-44)
Function                                     old     new   delta
ice_vsi_cfg_txq                             1873    1899     +26
ice_setup_rx_ctx.constprop                  1529    1459     -70
Total: Before=1459555, After=1459511, chg -0.00%

Thus, the fields are left in the same order as the packed bit layout,
despite the gaps this causes.

Signed-off-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Reviewed-by: default avatarPrzemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20241210-packing-pack-fields-and-ice-implementation-v10-8-ee56a47479ac@intel.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent dc4305be
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