(In reply to Uwe Bonnes from comment #4) > Outch: 100 k git log lines between 5.8 and 5.9 > > Only > f4b9d8a582f738c24ebeabce5cc15f4b8159d74e: USB: cdc-acm: rework > notification_buffer resizing > > explicit mentions CDC-ACM in the commit message/ The commit is likely irrelevant with such a performance change. Could you try performing git-bisect locally to spot out the regression commit?