On 2020-11-19 09:45:08 [+0200], Julian Wiedmann wrote: > On 18.11.20 12:53, Sebastian Andrzej Siewior wrote: > > The size of struct th_header is 8 byte and the size of struct th_sweep > > is 16 byte. The memory for is allocated, initialized, used and > > deallocated a few lines later. > > > > It is more efficient to avoid the allocation/free dance and keeping the > > variable on stack. Especially since the compiler is smart enough to not > > allocate the memory on stack but assign the values directly. > > > > Declare struct th_sweep/th_header on stack and initialize it to zero. > > Use the local variable instead of the pointer. > > > > Frankly, I'd much rather see us use the pointers that are returned from > skb_push() and skb_put(). No need for the on-stack & memcpy indirection. You are aware that the compiler optimizes the on-stack memory away and you get the zero-init for free due to the way the assignment is made? There is no memcpy() in the resulting code. Sebastian
