Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-08 Thread jianchao.wang
Hi Keith Thanks for your precious time and kindly response. On 02/08/2018 11:15 PM, Keith Busch wrote: > On Thu, Feb 08, 2018 at 10:17:00PM +0800, jianchao.wang wrote: >> There is a dangerous scenario which caused by nvme_wait_freeze in >> nvme_reset_work. >> please consider it. >> >>

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-08 Thread jianchao.wang
Hi Keith Thanks for your precious time and kindly response. On 02/08/2018 11:15 PM, Keith Busch wrote: > On Thu, Feb 08, 2018 at 10:17:00PM +0800, jianchao.wang wrote: >> There is a dangerous scenario which caused by nvme_wait_freeze in >> nvme_reset_work. >> please consider it. >> >>

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-08 Thread Keith Busch
On Thu, Feb 08, 2018 at 10:17:00PM +0800, jianchao.wang wrote: > There is a dangerous scenario which caused by nvme_wait_freeze in > nvme_reset_work. > please consider it. > > nvme_reset_work > -> nvme_start_queues > -> nvme_wait_freeze > > if the controller no response, we have to rely on

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-08 Thread Keith Busch
On Thu, Feb 08, 2018 at 10:17:00PM +0800, jianchao.wang wrote: > There is a dangerous scenario which caused by nvme_wait_freeze in > nvme_reset_work. > please consider it. > > nvme_reset_work > -> nvme_start_queues > -> nvme_wait_freeze > > if the controller no response, we have to rely on

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-08 Thread jianchao.wang
Hi Keith Sorry for bothering you again. ;) There is a dangerous scenario which caused by nvme_wait_freeze in nvme_reset_work. please consider it. nvme_reset_work -> nvme_start_queues -> nvme_wait_freeze if the controller no response, we have to rely on the timeout path. there are issues

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-08 Thread jianchao.wang
Hi Keith Sorry for bothering you again. ;) There is a dangerous scenario which caused by nvme_wait_freeze in nvme_reset_work. please consider it. nvme_reset_work -> nvme_start_queues -> nvme_wait_freeze if the controller no response, we have to rely on the timeout path. there are issues

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-07 Thread jianchao.wang
Hi Keith Really thanks for your your precious time and kindly directive. That's really appreciated. :) On 02/08/2018 12:13 AM, Keith Busch wrote: > On Wed, Feb 07, 2018 at 10:13:51AM +0800, jianchao.wang wrote: >> What's the difference ? Can you please point out. >> I have shared my

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-07 Thread jianchao.wang
Hi Keith Really thanks for your your precious time and kindly directive. That's really appreciated. :) On 02/08/2018 12:13 AM, Keith Busch wrote: > On Wed, Feb 07, 2018 at 10:13:51AM +0800, jianchao.wang wrote: >> What's the difference ? Can you please point out. >> I have shared my

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-07 Thread Keith Busch
On Wed, Feb 07, 2018 at 10:13:51AM +0800, jianchao.wang wrote: > What's the difference ? Can you please point out. > I have shared my understanding below. > But actually, I don't get the point what's the difference you said. It sounds like you have all the pieces. Just keep this in mind: we don't

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-07 Thread Keith Busch
On Wed, Feb 07, 2018 at 10:13:51AM +0800, jianchao.wang wrote: > What's the difference ? Can you please point out. > I have shared my understanding below. > But actually, I don't get the point what's the difference you said. It sounds like you have all the pieces. Just keep this in mind: we don't

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-06 Thread jianchao.wang
Hi Keith Sorry for bothering you again. On 02/07/2018 10:03 AM, jianchao.wang wrote: > Hi Keith > > Thanks for your time and kindly response on this. > > On 02/06/2018 11:13 PM, Keith Busch wrote: >> On Tue, Feb 06, 2018 at 09:46:36AM +0800, jianchao.wang wrote: >>> Hi Keith >>> >>> Thanks for

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-06 Thread jianchao.wang
Hi Keith Sorry for bothering you again. On 02/07/2018 10:03 AM, jianchao.wang wrote: > Hi Keith > > Thanks for your time and kindly response on this. > > On 02/06/2018 11:13 PM, Keith Busch wrote: >> On Tue, Feb 06, 2018 at 09:46:36AM +0800, jianchao.wang wrote: >>> Hi Keith >>> >>> Thanks for

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-06 Thread jianchao.wang
Hi Keith Thanks for your time and kindly response on this. On 02/06/2018 11:13 PM, Keith Busch wrote: > On Tue, Feb 06, 2018 at 09:46:36AM +0800, jianchao.wang wrote: >> Hi Keith >> >> Thanks for your kindly response. >> >> On 02/05/2018 11:13 PM, Keith Busch wrote: >>> but how many requests

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-06 Thread jianchao.wang
Hi Keith Thanks for your time and kindly response on this. On 02/06/2018 11:13 PM, Keith Busch wrote: > On Tue, Feb 06, 2018 at 09:46:36AM +0800, jianchao.wang wrote: >> Hi Keith >> >> Thanks for your kindly response. >> >> On 02/05/2018 11:13 PM, Keith Busch wrote: >>> but how many requests

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-06 Thread Keith Busch
On Tue, Feb 06, 2018 at 09:46:36AM +0800, jianchao.wang wrote: > Hi Keith > > Thanks for your kindly response. > > On 02/05/2018 11:13 PM, Keith Busch wrote: > > but how many requests are you letting enter to their demise by > > freezing on the wrong side of the reset? > > There are only two

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-06 Thread Keith Busch
On Tue, Feb 06, 2018 at 09:46:36AM +0800, jianchao.wang wrote: > Hi Keith > > Thanks for your kindly response. > > On 02/05/2018 11:13 PM, Keith Busch wrote: > > but how many requests are you letting enter to their demise by > > freezing on the wrong side of the reset? > > There are only two

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-05 Thread jianchao.wang
Hi Keith Thanks for your kindly response. On 02/05/2018 11:13 PM, Keith Busch wrote: > but how many requests are you letting enter to their demise by > freezing on the wrong side of the reset? There are only two difference with this patch from the original one. 1. Don't freeze the queue for

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-05 Thread jianchao.wang
Hi Keith Thanks for your kindly response. On 02/05/2018 11:13 PM, Keith Busch wrote: > but how many requests are you letting enter to their demise by > freezing on the wrong side of the reset? There are only two difference with this patch from the original one. 1. Don't freeze the queue for

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-05 Thread Keith Busch
On Mon, Feb 05, 2018 at 10:26:03AM +0800, jianchao.wang wrote: > > Freezing is not just for shutdown. It's also used so > > blk_mq_update_nr_hw_queues will work if the queue count changes across > > resets. > blk_mq_update_nr_hw_queues will freeze the queue itself. Please refer to. > static void

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-05 Thread Keith Busch
On Mon, Feb 05, 2018 at 10:26:03AM +0800, jianchao.wang wrote: > > Freezing is not just for shutdown. It's also used so > > blk_mq_update_nr_hw_queues will work if the queue count changes across > > resets. > blk_mq_update_nr_hw_queues will freeze the queue itself. Please refer to. > static void

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-04 Thread jianchao.wang
Hi Keith Thanks for your kindly response. On 02/03/2018 02:24 AM, Keith Busch wrote: > On Fri, Feb 02, 2018 at 03:00:45PM +0800, Jianchao Wang wrote: >> Currently, request queue will be frozen and quiesced for both reset >> and shutdown case. This will trigger ioq requests in RECONNECTING >>

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-04 Thread jianchao.wang
Hi Keith Thanks for your kindly response. On 02/03/2018 02:24 AM, Keith Busch wrote: > On Fri, Feb 02, 2018 at 03:00:45PM +0800, Jianchao Wang wrote: >> Currently, request queue will be frozen and quiesced for both reset >> and shutdown case. This will trigger ioq requests in RECONNECTING >>

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-02 Thread Keith Busch
On Fri, Feb 02, 2018 at 03:00:45PM +0800, Jianchao Wang wrote: > Currently, request queue will be frozen and quiesced for both reset > and shutdown case. This will trigger ioq requests in RECONNECTING > state which should be avoided to prepare for following patch. > Just freeze request queue for

Re: [PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-02 Thread Keith Busch
On Fri, Feb 02, 2018 at 03:00:45PM +0800, Jianchao Wang wrote: > Currently, request queue will be frozen and quiesced for both reset > and shutdown case. This will trigger ioq requests in RECONNECTING > state which should be avoided to prepare for following patch. > Just freeze request queue for

[PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-01 Thread Jianchao Wang
Currently, request queue will be frozen and quiesced for both reset and shutdown case. This will trigger ioq requests in RECONNECTING state which should be avoided to prepare for following patch. Just freeze request queue for shutdown case and drain all the resudual entered requests after

[PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-01 Thread Jianchao Wang
Currently, request queue will be frozen and quiesced for both reset and shutdown case. This will trigger ioq requests in RECONNECTING state which should be avoided to prepare for following patch. Just freeze request queue for shutdown case and drain all the resudual entered requests after

[PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-01 Thread Jianchao Wang
Currently, request queue will be frozen and quiesced for both reset and shutdown case. This will trigger ioq requests in RECONNECTING state which should be avoided to prepare for following patch. Just freeze request queue for shutdown case and drain all the resudual entered requests after

[PATCH 2/6] nvme-pci: fix the freeze and quiesce for shutdown and reset case

2018-02-01 Thread Jianchao Wang
Currently, request queue will be frozen and quiesced for both reset and shutdown case. This will trigger ioq requests in RECONNECTING state which should be avoided to prepare for following patch. Just freeze request queue for shutdown case and drain all the resudual entered requests after