Re: Is BIO_RW_FAILFAST really usable?

2007-12-05 Thread Neil Brown
On Tuesday December 4, [EMAIL PROTECTED] wrote: > > Hrmpf. It looks like the SCSI layer is a little too trigger happy. Any > chance you could try and trace where this happens? in scsi_lib.c, in scsi_request_fn, near the top of the main while (!blk_queue_plugged(q)) { loop: if

Re: Is BIO_RW_FAILFAST really usable?

2007-12-04 Thread Jens Axboe
On Tue, Dec 04 2007, Neil Brown wrote: > > I've been looking at use BIO_RW_FAILFAST in md/raid to improve > handling of some error cases. > > This is particularly significant for the DASD driver (s390 specific). > I believe it uses optic fibre to connect to the drives. When one of > these paths

Re: Is BIO_RW_FAILFAST really usable?

2007-12-03 Thread Andrey Borzenkov
Jeff Garzik wrote: > Neil Brown wrote: >> I've been looking at use BIO_RW_FAILFAST in md/raid to improve >> handling of some error cases. >> >> This is particularly significant for the DASD driver (s390 specific). >> I believe it uses optic fibre to connect to the drives. When one of >> these pa

Re: Is BIO_RW_FAILFAST really usable?

2007-12-03 Thread Jeff Garzik
Neil Brown wrote: I've been looking at use BIO_RW_FAILFAST in md/raid to improve handling of some error cases. This is particularly significant for the DASD driver (s390 specific). I believe it uses optic fibre to connect to the drives. When one of these paths is unplugged, IO requests will blo

Is BIO_RW_FAILFAST really usable?

2007-12-03 Thread Neil Brown
I've been looking at use BIO_RW_FAILFAST in md/raid to improve handling of some error cases. This is particularly significant for the DASD driver (s390 specific). I believe it uses optic fibre to connect to the drives. When one of these paths is unplugged, IO requests will block until an operato