Re: [PATCH 1/2] nvme: set io-scheduler requirement for ZNS

2020-09-07 Thread Damien Le Moal
On 2020/09/07 20:54, Kanchan Joshi wrote: > On Mon, Sep 7, 2020 at 5:07 PM Damien Le Moal wrote: >> >> On 2020/09/07 20:24, Kanchan Joshi wrote: >>> On Mon, Sep 7, 2020 at 1:52 PM Damien Le Moal wrote: On 2020/09/07 16:01, Kanchan Joshi wrote: >> Even for SMR, the user is free to se

Re: [PATCH 1/2] nvme: set io-scheduler requirement for ZNS

2020-09-07 Thread Kanchan Joshi
On Mon, Sep 7, 2020 at 5:07 PM Damien Le Moal wrote: > > On 2020/09/07 20:24, Kanchan Joshi wrote: > > On Mon, Sep 7, 2020 at 1:52 PM Damien Le Moal wrote: > >> > >> On 2020/09/07 16:01, Kanchan Joshi wrote: > Even for SMR, the user is free to set the elevator to none, which > disables

Re: [PATCH 1/2] nvme: set io-scheduler requirement for ZNS

2020-09-07 Thread Damien Le Moal
On 2020/09/07 20:24, Kanchan Joshi wrote: > On Mon, Sep 7, 2020 at 1:52 PM Damien Le Moal wrote: >> >> On 2020/09/07 16:01, Kanchan Joshi wrote: Even for SMR, the user is free to set the elevator to none, which disables zone write locking. Issuing writes correctly then becomes the

Re: [PATCH 1/2] nvme: set io-scheduler requirement for ZNS

2020-09-07 Thread Kanchan Joshi
On Mon, Sep 7, 2020 at 1:52 PM Damien Le Moal wrote: > > On 2020/09/07 16:01, Kanchan Joshi wrote: > >> Even for SMR, the user is free to set the elevator to none, which disables > >> zone > >> write locking. Issuing writes correctly then becomes the responsibility of > >> the > >> application.

Re: [PATCH 1/2] nvme: set io-scheduler requirement for ZNS

2020-09-07 Thread Damien Le Moal
On 2020/09/07 16:01, Kanchan Joshi wrote: >> Even for SMR, the user is free to set the elevator to none, which disables >> zone >> write locking. Issuing writes correctly then becomes the responsibility of >> the >> application. This can be useful for settings that for instance use NCQ I/O >> pri

Re: [PATCH 1/2] nvme: set io-scheduler requirement for ZNS

2020-09-07 Thread Kanchan Joshi
On Wed, Aug 19, 2020 at 4:47 PM Damien Le Moal wrote: > > On 2020/08/19 19:32, Kanchan Joshi wrote: > > On Wed, Aug 19, 2020 at 3:08 PM Damien Le Moal > > wrote: > >> > >> On 2020/08/19 18:27, Kanchan Joshi wrote: > >>> On Tue, Aug 18, 2020 at 12:46 PM Christoph Hellwig wrote: > > On

Re: [PATCH 1/2] nvme: set io-scheduler requirement for ZNS

2020-08-19 Thread Damien Le Moal
On 2020/08/19 19:32, Kanchan Joshi wrote: > On Wed, Aug 19, 2020 at 3:08 PM Damien Le Moal wrote: >> >> On 2020/08/19 18:27, Kanchan Joshi wrote: >>> On Tue, Aug 18, 2020 at 12:46 PM Christoph Hellwig wrote: On Tue, Aug 18, 2020 at 10:59:35AM +0530, Kanchan Joshi wrote: > Set elevat

Re: [PATCH 1/2] nvme: set io-scheduler requirement for ZNS

2020-08-19 Thread Kanchan Joshi
On Wed, Aug 19, 2020 at 3:08 PM Damien Le Moal wrote: > > On 2020/08/19 18:27, Kanchan Joshi wrote: > > On Tue, Aug 18, 2020 at 12:46 PM Christoph Hellwig wrote: > >> > >> On Tue, Aug 18, 2020 at 10:59:35AM +0530, Kanchan Joshi wrote: > >>> Set elevator feature ELEVATOR_F_ZBD_SEQ_WRITE required f

Re: [PATCH 1/2] nvme: set io-scheduler requirement for ZNS

2020-08-19 Thread Damien Le Moal
On 2020/08/19 18:27, Kanchan Joshi wrote: > On Tue, Aug 18, 2020 at 12:46 PM Christoph Hellwig wrote: >> >> On Tue, Aug 18, 2020 at 10:59:35AM +0530, Kanchan Joshi wrote: >>> Set elevator feature ELEVATOR_F_ZBD_SEQ_WRITE required for ZNS. >> >> No, it is not. > > Are you saying MQ-Deadline (write

Re: [PATCH 1/2] nvme: set io-scheduler requirement for ZNS

2020-08-19 Thread Kanchan Joshi
On Tue, Aug 18, 2020 at 12:46 PM Christoph Hellwig wrote: > > On Tue, Aug 18, 2020 at 10:59:35AM +0530, Kanchan Joshi wrote: > > Set elevator feature ELEVATOR_F_ZBD_SEQ_WRITE required for ZNS. > > No, it is not. Are you saying MQ-Deadline (write-lock) is not needed for writes on ZNS? I see that n

Re: [PATCH 1/2] nvme: set io-scheduler requirement for ZNS

2020-08-18 Thread Christoph Hellwig
On Tue, Aug 18, 2020 at 10:59:35AM +0530, Kanchan Joshi wrote: > Set elevator feature ELEVATOR_F_ZBD_SEQ_WRITE required for ZNS. No, it is not.