"performance in general" is correct and usable in written English.
You can use it when talking about an individual or group's overall performance. For example, "The students' performance in general was impressive."
Performance in general seems to be deteriorating.
We are going to look at their performance in general".
Could there be a greater future for this type of mixed-genre performance in general?
This was typical of his foreign-policy performance in general, at least in the early years.
We are focused on improving our performance in General Merchandise and were pleased to see early signs of improvement.
Here's the context for my quote about what documents he possesses: "Q: Beyond the revelations about the spying system performance in general, what extra information has Snowden?
My problem wasn't just the inevitable mismatch between promise and fulfilment, but that the promise itself betrays what is best about the fringe (and live performance in general).
Congress's performance in general elections does not fully reflect this: it actually does better at the centre than in the states, where patronage politics is more intense.
(Some seasons back, the avant-garde director Elizabeth LeCompte and her admirable company the Wooster Group used Chekhov's "Three Sisters" as a jumping-off point from which to dissect the nature of performance in general).
Gridley's work is that of an adult having fun while commenting on her own performance and on performance in general, whereas Johanson sometimes seems like an overgrown boy who insists on taking up too much space.
Opposition parties cast the balloting as a mid-term gauge of public support for Mr. Lee's performance in general, his policies toward North Korea and his handling of the crisis over the sinking of the ship.
