Reminds me of how, after years of massive systemwide latency spikes, I finally discovered that XFS was to blame. It was blocking on I/O writes in the reclaim pa

Reminds me of how, after years of massive systemwide latency spikes, I finally discovered that XFS was to blame. It was blocking on I/O writes in the reclaim path... so even random processes that wanted to allocate some RAM but don't do any disk I/O ended up blocked. This was on a machine with tons of free RAM (the reclaim was for clean cache).