Performance regression in reindex.LevelAlign.time_reindex_level

[TomAugspurger]

https://pandas.pydata.org/speed/pandas/index.html#reindex.LevelAlign.time_reindex_level?commits=a0c8425a5f2b74e8a716defd799c4a3716f66eff-2a319238e47d3d7362188f7da4eb911199c423b8

Somewhere in a0c8425...2a31923

[dsaxton]

0b90685 seems to be the only commit in that range that touches index code. May be worth investigating @simonjayhawkins?

[jorisvandenbossche]

I suppose #35805 might be related to the same then?

[simonjayhawkins]

Thanks @dsaxton will look soon

[jreback]

no open PR for this, moving off 1.2