[net-next,v2,0/7] introduce DEFINE_FLEX() macro

Message

Przemek Kitszel Aug. 11, 2023, 12:08 p.m. UTC

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).

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              | 12 ++++
 include/linux/fortify-string.h              |  4 --
 include/linux/overflow.h                    | 27 +++++++++
 11 files changed, 113 insertions(+), 207 deletions(-)


base-commit: 6a1ed1430daa2ccf8ac457e0db93fb0925b801ca