From having played with/worked on profiling and optimizing Redis in the 2.6 timeframe, I can confirm that at least for small/simple operations, this is true, the data structure access is a small fraction of the cost.
One related choice that Redis makes (or made at the time) is to rely extremely heavily on the malloc implementation, rather than doing work to manage it's memory internally. Even a very trivial, naive free list provided a modest speed-up, for example.
There are a lot of these choices in the code base, largely owing to maintainability concerns (though antirez can surely speak for himself). Given how easy it is for an otherwise uninitiated C programmer such as myself to hack on it, I struggle to disagree with the prioritization. :)
One related choice that Redis makes (or made at the time) is to rely extremely heavily on the malloc implementation, rather than doing work to manage it's memory internally. Even a very trivial, naive free list provided a modest speed-up, for example.
There are a lot of these choices in the code base, largely owing to maintainability concerns (though antirez can surely speak for himself). Given how easy it is for an otherwise uninitiated C programmer such as myself to hack on it, I struggle to disagree with the prioritization. :)