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 >
