On Fri, Sep 23, 2016 at 07:45:00PM +0200, Manuel Bouyer wrote: > On Fri, Sep 23, 2016 at 05:15:16PM +0000, Eric Haszlakiewicz wrote: > > On September 23, 2016 10:51:30 AM EDT, Warner Losh <i...@bsdimp.com> wrote: > > >All NCQ gives you is the ability to schedule multiple requests and > > >to get notification of their completion (perhaps out of order). There's > > >no coherency features are all in NCQ. > > > > This seems like the key thing needed to avoid FUA: to implement fsync() you > > just wait for notifications of completion to be received, and once you have > > those for all requests pending when fsync was called, or started as part of > > the fsync, then you're done. > > *if you have the write cache disabled*
*Running with the write cache enabled is a bad idea*