Hello, On Mon, Sep 23, 2019 at 06:06:46PM +0300, Konstantin Khlebnikov wrote: > On 23/09/2019 17.52, Tejun Heo wrote: > >Hello, Konstantin. > > > >On Fri, Sep 20, 2019 at 10:39:33AM +0300, Konstantin Khlebnikov wrote: > >>With vm.dirty_write_behind 1 or 2 files are written even faster and > > > >Is the faster speed reproducible? I don't quite understand why this > >would be. > > Writing to disk simply starts earlier. I see. > >Generic write-behind would definitely have other benefits and also a > >bunch of regression possibilities. I'm not trying to say that > >write-behind isn't a good idea but it'd be useful to consider that a > >good portion of the benefits can already be obtained fairly easily. > > > > I'm afraid this could end badly if each simple task like file copying > will require own systemd job and container with manual tuning. At least the write window size part of it is pretty easy - the range of acceptable values is fiarly wide - and setting up a cgroup and running a command in it isn't that expensive. It's not like these need full-on containers. That said, yes, there sure are benefits to the kernel being able to detect and handle these conditions automagically. Thanks. -- tejun
