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author | Jacob Keller <jacob.e.keller@intel.com> | 2024-12-10 12:27:17 -0800 |
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committer | Jakub Kicinski <kuba@kernel.org> | 2024-12-11 20:13:00 -0800 |
commit | f72588a4267b2211d18328433035b629d24f6f03 (patch) | |
tree | 1848a431affece1951503507f0d6d8144e22f7fe /rust/helpers/task.c | |
parent | dc4305be467a6f84f66005cfc58557d56b5ab107 (diff) |
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: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Vladimir 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: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'rust/helpers/task.c')
0 files changed, 0 insertions, 0 deletions