Re: [PATCH V2 10/12] scsi: sd_zbc: Disable zone write locking with scsi-mq

2017-09-12 Thread Damien Le Moal
Ming, On 9/12/17 18:26, Ming Lei wrote: >>> OK, I suggest to document this guarantee of no write reorder for ZBC >>> somewhere, so that people will keep it in mind when trying to change >>> the current code. >> >> Have you looked at the comments in sd_zbc.c ? That is explained there. >> Granted,

Re: [PATCH V2 10/12] scsi: sd_zbc: Disable zone write locking with scsi-mq

2017-09-12 Thread Ming Lei
On Tue, Sep 12, 2017 at 05:24:02PM +0900, Damien Le Moal wrote: > Ming, > > On 9/10/17 14:10, Ming Lei wrote: > > On Fri, Sep 08, 2017 at 09:53:53AM -0700, Damien Le Moal wrote: > >> Ming, > >> > >> On 9/8/17 05:43, Ming Lei wrote: > >>> Hi Damien, > >>> > >>> On Fri, Sep 08, 2017 at 01:16:38AM

Re: [PATCH V2 10/12] scsi: sd_zbc: Disable zone write locking with scsi-mq

2017-09-12 Thread Damien Le Moal
Ming, On 9/10/17 14:10, Ming Lei wrote: > On Fri, Sep 08, 2017 at 09:53:53AM -0700, Damien Le Moal wrote: >> Ming, >> >> On 9/8/17 05:43, Ming Lei wrote: >>> Hi Damien, >>> >>> On Fri, Sep 08, 2017 at 01:16:38AM +0900, Damien Le Moal wrote: In the case of a ZBC disk used with scsi-mq, zone

Re: [PATCH V2 10/12] scsi: sd_zbc: Disable zone write locking with scsi-mq

2017-09-09 Thread Ming Lei
On Fri, Sep 08, 2017 at 09:53:53AM -0700, Damien Le Moal wrote: > Ming, > > On 9/8/17 05:43, Ming Lei wrote: > > Hi Damien, > > > > On Fri, Sep 08, 2017 at 01:16:38AM +0900, Damien Le Moal wrote: > >> In the case of a ZBC disk used with scsi-mq, zone write locking does > >> not prevent write

Re: [PATCH V2 10/12] scsi: sd_zbc: Disable zone write locking with scsi-mq

2017-09-08 Thread Damien Le Moal
Ming, On 9/8/17 05:43, Ming Lei wrote: > Hi Damien, > > On Fri, Sep 08, 2017 at 01:16:38AM +0900, Damien Le Moal wrote: >> In the case of a ZBC disk used with scsi-mq, zone write locking does >> not prevent write reordering in sequential zones. Unlike the legacy >> case, zone locking can only be

Re: [PATCH V2 10/12] scsi: sd_zbc: Disable zone write locking with scsi-mq

2017-09-08 Thread Ming Lei
Hi Damien, On Fri, Sep 08, 2017 at 01:16:38AM +0900, Damien Le Moal wrote: > In the case of a ZBC disk used with scsi-mq, zone write locking does > not prevent write reordering in sequential zones. Unlike the legacy > case, zone locking can only be done after the command request is > removed from

[PATCH V2 10/12] scsi: sd_zbc: Disable zone write locking with scsi-mq

2017-09-07 Thread Damien Le Moal
In the case of a ZBC disk used with scsi-mq, zone write locking does not prevent write reordering in sequential zones. Unlike the legacy case, zone locking can only be done after the command request is removed from the scheduler dispatch queue. That is, at the time of zone locking, the write