[PATCH net-next v5 0/7] introduce DEFINE_FLEX() macro

Przemek Kitszel
2023-09-12T12:04:03Z

Add DEFINE_FLEX() macro, that helps on-stack allocation of structures
with trailing flex array member.
Expose __struct_size() macro which reads size of data allocated
by DEFINE_FLEX().

Accompany new macros introduction with actual usage,
in the ice driver - hence targeting for netdev tree.

Obvious benefits include simpler resulting code, less heap usage,
less error checking. Less obvious is the fact that compiler has
more room to optimize, and as a whole, even with more stuff on the stack,
we end up with overall better (smaller) report from bloat-o-meter:
add/remove: 8/6 grow/shrink: 7/18 up/down: 2211/-2270 (-59)
(individual results in each patch).

v5: same as v4, just not RFC
v4: _Static_assert() to ensure compiletime const count param
v3: tidy up 1st patch
v2: Kees: reusing __struct_size() instead of doubling it as a new macro

Przemek Kitszel (7):
overflow: add DEFINE_FLEX() for on-stack allocs
ice: ice_sched_remove_elems: replace 1 elem array param by u32
ice: drop two params of ice_aq_move_sched_elems()
ice: make use of DEFINE_FLEX() in ice_ddp.c
ice: make use of DEFINE_FLEX() for struct ice_aqc_add_tx_qgrp
ice: make use of DEFINE_FLEX() for struct ice_aqc_dis_txq_item
ice: make use of DEFINE_FLEX() in ice_switch.c

drivers/net/ethernet/intel/ice/ice_common.c | 20 ++-----
drivers/net/ethernet/intel/ice/ice_ddp.c | 39 ++++---------
drivers/net/ethernet/intel/ice/ice_lag.c | 48 ++++------------
drivers/net/ethernet/intel/ice/ice_lib.c | 23 ++------
drivers/net/ethernet/intel/ice/ice_sched.c | 56 ++++++------------
drivers/net/ethernet/intel/ice/ice_sched.h | 6 +-
drivers/net/ethernet/intel/ice/ice_switch.c | 63 +++++----------------
drivers/net/ethernet/intel/ice/ice_xsk.c | 22 +++----
include/linux/compiler_types.h | 32 +++++++----
include/linux/fortify-string.h | 4 --
include/linux/overflow.h | 35 ++++++++++++
11 files changed, 130 insertions(+), 218 deletions(-)

base-commit: 73be7fb14e83d24383f840a22f24d3ed222ca319
--
2.40.1