I must admit that I didn't have a need for such facility yet, wasn't familiar with it, but now curious since when it was available. According to [1] it was implemented already in 2.6.38. It was discussed back in 2006 [2]. So, yeah, no need to wait for a kernel update ;-}
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[ 5.3 ms ] story [ 12.7 ms ] thread[1] https://static.linaro.org/connect/san19/presentations/san19-...
[2] https://lwn.net/Articles/210502/