Hi, Thanks a lot fo Dave Chinner, The 'Throughput' of dbench include not only 'write', but also include 'read' in dbench too. And 'max_latency' include not only 'write', but also include others too. 1)dbench result example1 WriteX 365460 4.474 2279.808 ... Throughput 385.697 MB/sec (sync open) 32 clients 32 procs max_latency=2279.818 ms 2)dbench result example2 WriteX 741543 3.521 16.380 ... Throughput 779.972 MB/sec (sync open) 48 clients 48 procs max_latency=11.246 ms for ext4, with more clients(32->80), the Throughput of ext4 is over 6Gb/s too. Best Regards Wang Yugui (wangyugui@xxxxxxxxxxxx) 2020/10/15 > Hi, > > For xfs sync performance optimization, there is an option 'osyncisdsync' > which is removed in 4.0(man xfs) > > the xfs sync performance optimization in linux 5.4.70/5.9.0 is beyond > 'osyncisdsync'? When multiple write(sync) at the same time, just some of > them are guaranteed? > > Or deduplication(based on reflink=1) help the sync write? > and 'mkfs.xfs -m reflink=0' failed to disable it? > > iotop show that 'Actual DISK WRITE:' is NOT over hardware throughput. > > Best Regards > Wang Yugui (wangyugui@xxxxxxxxxxxx) > 2020/10/14 > > > Hi, > > > > #any reply, please Cc: wangyugui@xxxxxxxxxxxx > > > > dbench throughput(sync, reflink=0|1) on xfs over hardware > > throughput(6Gb/s=750MB/s). > > > > Is this a bug of xfs sync? or some feature of performance optimization? > > > > we test mkfs.xfs -m reflink=0|1, crc=0|1, still over hardware > > throughput(6Gb/s=750MB/s). > > > > Disk: TOSHIBA PX05SMQ040 > > This is a 12Gb/s SAS SSD disk, but connect to 6Gb/s SAS HBA, > > so it works with 6Gb/s. > > > > dbench -s -t 60 -D /xfs 32 > > #Throughput 884.406 MB/sec (sync open) > > > > > > dbench -s -t 60 -D /xfs 1 > > #Throughput 149.172 MB/sec (sync open) > > > > we test the same disk with ext4 filesystem, > > the throughput is very close to, but less than the hardware limit. > > > > dbench -s -t 60 -D /ext4 32 > > #Throughput 740.95 MB/sec (sync open) > > > > dbench -s -t 60 -D /ext4 1 > > #Throughput 124.67 MB/sec (sync open) > > > > linux kernel: 5.4.70, 5.9.0 > > > > Best Regards > > Wang Yugui (wangyugui@xxxxxxxxxxxx) > > 2020/10/13 > > >
