On 24/02/2019 11:54, Max Gurtovoy wrote: > > On 2/22/2019 7:55 AM, Johannes Thumshirn wrote: >> On 22/02/2019 01:41, Chaitanya Kulkarni wrote: >> [...] >>> As per specified in the patch, this is only useful for testing, then we >>> should modify the test scripts so that on creation of the ctrl we switch >>> to the buffered I/O before running fio. >> Or on any other file-system that does not support DIO.. > > Do we really want to support these kind of filesystems for fabrics > backend device ? only for testing ? > > What is the status of iSCSI/SRP targets in this case ?
iSCSI/SRP passes in the following: /* * Use O_DSYNC by default instead of O_SYNC to forgo syncing * of pure timestamp updates. */ flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC; Meaning it uses O_DSYNC, so for instance if I do a dd to tmpfs with O_DSYNC: $ dd if=/dev/zero of=/dev/shm/foo oflag=dsync bs=4k count=1 1+0 records in 1+0 records out 4096 bytes (4.1 kB, 4.0 KiB) copied, 0.000175094 s, 23.4 MB/s Same with O_DIRECT: $ dd if=/dev/zero of=/dev/shm/foo oflag=direct bs=4k count=1 dd: failed to open '/dev/shm/foo': Invalid argument -- Johannes Thumshirn SUSE Labs Filesystems jthumsh...@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
