I think this depends very much where you live. Where I live, and have done for the past couple of years, there is a significant (25% is a conservative estimate) Eastern European population, and I have heard things when out in town, and also seen things on a more official basis, that are much much worse than things I have seen and heard when I have lived previously in areas where there were significant "non-white" populations. I have actually been pretty shocked about it tbh.
The concept of 'race' is a confused muddle of physical (inherited) and cultural (learned) characteristics which are very difficult to disintengle. Anthropologists are moving away from the concept because it seems to have less and less scientific coherence and validity as they learn more about just how mixed up we all are.
Your post, like the earlier one referring to discrimination between Thais and Vietnamese as 'racism' is all too typical of the confusion as to what 'racism' actually is which characterises this thread.
A Pole, for instance, being an Indo-European (of the Slavic subgroup), is actually of the same 'race' as the majority inhabitants of the British Isles, be they Celtic, Anglo-Saxon or part of some other Germanic subgroup. A native Brit may make some nasty comments or discriminate against a Pole or other Eastern European (all of whom - with the exception of the Hungarians - are also basically Indo-European with small admixtures of from Turkic and Finno-Ugric such as the Avars, Bulgars, Khazars and Huns) but if the word is to have any meaning at all it cannot by definition amount to 'racism' as these newcomers are of the same 'race' as the majority population of the British Isles. It would paradoxically be only if the person doing the taunting or persecuting were to happen to be a non-Indo-European immigrant, would such behaviour amount to 'racism'.
Similarly the Thai and Vietnamese belong to the same 'race' of historically interconnected peoples who live in Southern China and South Eastern Asia. If these examples truly amount to 'racism', then a Lancastrian making rude comments or discriminating against a Yorkshireman, or vice versa, would also amount to 'racism'.
I've put 'race' and 'racism' in inverted commas throughout as I've always believed that we belong to one human race and that this obsession with 'racism' and the constant harping on about distinctions which I've said earlier are a confused muddle of physical and cultural characteristics is one of the primary causes of dissension between peoples and does little in fact to help under-privileged or disadvantaged groups.