On Wed, Oct 14, 2020 at 11:32:11AM +0800, Wang Yugui wrote: > > > On Tue, Oct 13, 2020 at 10:11:13PM +0800, Wang Yugui wrote: > > > Hi, > > > > > > dbench throughput on xfs over hardware limit(6Gb/s=750MB/s). > > > > > > Is this a bug or some feature of performance optimization? > > > > dbench measures page cache throughput, not physical IO throughput. > > This sort of results is expected. > > We use 'dbench -s', so it should be physical IO. > -s Use synchronous file IO on all file operations. Reads can still be served from the page cache without doing physical IO. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx