Linux: Low Latency and Filesystems

Continuing the earlier discussion about low latency and Ingo Molnar’s voluntary kernel preemption patch, the conversation moved onto the affect a filesystem can have on latency. Specifically, 2.6 maintainer Andrew Morton noted that ReiserFS was known to have some latency issues in both the 2.4 and 2.6 Linux kernels, “resierfs: yes, it’s a problem. I ‘fixed’ it multiple times in 2.4, but the fixes ended up breaking the fs in subtle ways and I eventually gave up.” However, he did go on to note, “actually, the 2.4 low-latency patch does still have some reiserfs fixes, so it’s probably better than reiserfs in 2.6.”