On Fri, Sep 20, 2019 at 4:05 PM Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > > Now, I hear you say "those are so small these days that it doesn't > matter". And maybe you're right. But particularly for slow media, > triggering good streaming write behavior has been a problem in the > past. Which reminds me: the writebehind trigger should likely be tied to the estimate of the bdi write speed. We _do_ have that avg_write_bandwidth thing in the bdi_writeback structure, it sounds like a potentially good idea to try to use that to estimate when to do writebehind. No? Linus