Must be actual walljumps. Jumping inside a wall and hitting the block directly above you does not count as a walljump. Cramming yourself between a wall and the edge of the screen and jumping from there also does not count as a walljump.
Here is an improved TAS of Super Mario Bros. that doesn’t actually complete the game, but instead performs 10 walljumps as quickly as possible.
In this category, players must catch the wall and jump off of it 10 times in total. Most of the time, players would be able to perform those walljumps in World 1-1’s underground bonus room. They would also perform one of the easiest walljumps first at the first pipe.
I perform those walljumps in World 1-1’s first pipe rather than the first pit, and oddly enough, it seems to be a more suitable place to perform as many walljumps as a TASer would like in record time instead of the latter. The reason why is that even though I can perform a walljump by pressing A and holding it for five frames, the pipe is actually closer to the start position than the pit, meaning the walljumps are executed faster than usual.
Because of that, this run is 3.88 seconds faster than my other TAS submitted in the userfiles.