[ipfs/go-bitswap] internal.StartSpan spends half its time calling fmt.Sprintf

[m42a]

In the attached 30 second cpu profile, ipfs spends 16.11s calling internal.StartSpan. Almost half of that time (7.97s) is spent calling fmt.Sprintf, which is used to prepend "Bitswap." to the operation name. However, StartSpan is always called with a constant string, so if the callers were modified to add "Bitswap." to the operation name instead it would speed up the ipfs daemon by 26% in this case. Additionally, since StartSpan would no longer create a new string that needs to be garbage-collected every time it is called, the CPU usage of the garbage collector would decrease as well.

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[welcome]

Thank you for submitting your first issue to this repository! A maintainer will be here shortly to triage and review.
In the meantime, please double-check that you have provided all the necessary information to make this process easy! Any information that can help save additional round trips is useful! We currently aim to give initial feedback within two business days. If this does not happen, feel free to leave a comment.
Please keep an eye on how this issue will be labeled, as labels give an overview of priorities, assignments and additional actions requested by the maintainers:

• "Priority" labels will show how urgent this is for the team.
• "Status" labels will show if this is ready to be worked on, blocked, or in progress.
• "Need" labels will indicate if additional input or analysis is required.

Finally, remember to use https://discuss.ipfs.io if you just need general support.