[v5,0/5] scsi: ufs: Add Host Performance Booster Support

Message

Daejun Park July 2, 2020, 11:19 p.m. UTC

Changelog:

v4 -> v5
Delete unused macro define.

v3 -> v4
1. Cleanup.

v2 -> v3
1. Add checking input module parameter value.
2. Change base commit from 5.8/scsi-queue to 5.9/scsi-queue.
3. Cleanup for unused variables and label.

v1 -> v2
1. Change the full boilerplate text to SPDX style.
2. Adopt dynamic allocation for sub-region data structure.
3. Cleanup.

NAND flash memory-based storage devices use Flash Translation Layer (FTL)
to translate logical addresses of I/O requests to corresponding flash
memory addresses. Mobile storage devices typically have RAM with
constrained size, thus lack in memory to keep the whole mapping table.
Therefore, mapping tables are partially retrieved from NAND flash on
demand, causing random-read performance degradation.

To improve random read performance, JESD220-3 (HPB v1.0) proposes HPB
(Host Performance Booster) which uses host system memory as a cache for the
FTL mapping table. By using HPB, FTL data can be read from host memory
faster than from NAND flash memory. 

The current version only supports the DCM (device control mode).
This patch consists of 4 parts to support HPB feature.

1) UFS-feature layer
2) HPB probe and initialization process
3) READ -> HPB READ using cached map information
4) L2P (logical to physical) map management

The UFS-feature is an additional layer to avoid the structure in which the
UFS-core driver and the UFS-feature are entangled with each other in a 
single module.
By adding the layer, UFS-features composed of various combinations can be
supported. Also, even if a new feature is added, modification of the 
UFS-core driver can be minimized.

In the HPB probe and init process, the device information of the UFS is
queried. After checking supported features, the data structure for the HPB
is initialized according to the device information.

A read I/O in the active sub-region where the map is cached is changed to
HPB READ by the HPB module.

The HPB module manages the L2P map using information received from the
device. For active sub-region, the HPB module caches through ufshpb_map
request. For the in-active region, the HPB module discards the L2P map.
When a write I/O occurs in an active sub-region area, associated dirty
bitmap checked as dirty for preventing stale read.

HPB is shown to have a performance improvement of 58 - 67% for random read
workload. [1]

This series patches are based on the 5.9/scsi-queue branch.

[1]:
https://www.usenix.org/conference/hotstorage17/program/presentation/jeong

Daejun park (5):
 scsi: ufs: Add UFS feature related parameter
 scsi: ufs: Add UFS feature layer
 scsi: ufs: Introduce HPB module
 scsi: ufs: L2P map management for HPB read
 scsi: ufs: Prepare HPB read for cached sub-region
 
 drivers/scsi/ufs/Kconfig      |    9 +
 drivers/scsi/ufs/Makefile     |    3 +-
 drivers/scsi/ufs/ufs.h        |   12 +
 drivers/scsi/ufs/ufsfeature.c |  148 +++
 drivers/scsi/ufs/ufsfeature.h |   69 ++
 drivers/scsi/ufs/ufshcd.c     |   19 +
 drivers/scsi/ufs/ufshcd.h     |    3 +
 drivers/scsi/ufs/ufshpb.c     | 1997 ++++++++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufshpb.h     |  234 +++++
 9 files changed, 2493 insertions(+), 1 deletion(-)
 created mode 100644 drivers/scsi/ufs/ufsfeature.c
 created mode 100644 drivers/scsi/ufs/ufsfeature.h
 created mode 100644 drivers/scsi/ufs/ufshpb.c
 created mode 100644 drivers/scsi/ufs/ufshpb.h

Comments

Daejun Park July 8, 2020, 11:26 p.m. UTC | #1

Hello,

Just a gentle reminder that I'd like some feedback.
Any suggestions here?

Thanks,
Daejun

Avri Altman July 9, 2020, 5:16 a.m. UTC | #2

> Hello,
> 
> Just a gentle reminder that I'd like some feedback.
> Any suggestions here?
If no-one objects, I think you can submit your patches for review as non-RFC.

Thanks,
Avri

> 
> Thanks,
> Daejun

Daejun Park July 9, 2020, 7:29 a.m. UTC | #3

> Hello,
> > 
> > Just a gentle reminder that I'd like some feedback.
> > Any suggestions here?
> If no-one objects, I think you can submit your patches for review as non-RFC.
> 
[PATCH v5 0/5] scsi: ufs: Add Host Performance Booster Support
~~~~~~
It is non-RFC version.

Thanks,
Daejun.

Avri Altman July 9, 2020, 8:40 a.m. UTC | #4

> > Hello,
> > >
> > > Just a gentle reminder that I'd like some feedback.
> > > Any suggestions here?
> > If no-one objects, I think you can submit your patches for review as non-
> RFC.
> >
> [PATCH v5 0/5] scsi: ufs: Add Host Performance Booster Support
> ~~~~~~
> It is non-RFC version.
Oops - sorry.  I was in RFC state of mind.

Bart - how do you want to proceed?

Thanks,
Avri

> 
> Thanks,
> Daejun.

Daejun Park July 13, 2020, 12:04 a.m. UTC | #5

Hi Bart,

> > Hello,
> > > >
> > > > Just a gentle reminder that I'd like some feedback.
> > > > Any suggestions here?
> > > If no-one objects, I think you can submit your patches for review as non-
> > RFC.
> > >
> > [PATCH v5 0/5] scsi: ufs: Add Host Performance Booster Support
> > ~~~~~~
> > It is non-RFC version.
> Oops - sorry.  I was in RFC state of mind.
> 
> Bart - how do you want to proceed?
> 
> Thanks,
> Avri
> 
> > 
> > Thanks,
> > Daejun.

Avri and I are waiting for your comments.
I hope to receive your mail soon.

Thanks,
Daejun

Bart Van Assche July 13, 2020, 1:08 a.m. UTC | #6

On 2020-07-09 01:40, Avri Altman wrote:
> Bart - how do you want to proceed?

Hi Avri and Daejun,

As far as I can see none of the five patches have Reviewed-by tags yet. I
think that Martin expects formal reviews for this patch series from one or
more reviewers who are not colleagues of the author of this patch series.

Note: recently I have been more busy than usual, hence the delayed reply.

Bart.

Daejun Park July 13, 2020, 1:27 a.m. UTC | #7

Hi Bart,

> > Bart - how do you want to proceed?
> 
> Hi Avri and Daejun,
> 
> As far as I can see none of the five patches have Reviewed-by tags yet. I
> think that Martin expects formal reviews for this patch series from one or
> more reviewers who are not colleagues of the author of this patch series.
> 
> Note: recently I have been more busy than usual, hence the delayed reply.
Thank you for replying to the email even though you are busy.

Arvi, Bean - if patches looks ok, can this series have your reviewed-by tag?

Thanks,
Daejun

Bean Huo July 13, 2020, 9:23 a.m. UTC | #8

On Mon, 2020-07-13 at 10:27 +0900, Daejun Park wrote:
> Hi Bart,
> 
> > > Bart - how do you want to proceed?
> > 
> > Hi Avri and Daejun,
> > 
> > As far as I can see none of the five patches have Reviewed-by tags
> > yet. I
> > think that Martin expects formal reviews for this patch series from
> > one or
> > more reviewers who are not colleagues of the author of this patch
> > series.
> > 
> > Note: recently I have been more busy than usual, hence the delayed
> > reply.
> 
> Thank you for replying to the email even though you are busy.
> 
> Arvi, Bean - if patches looks ok, can this series have your reviewed-
> by tag?
> 
> Thanks,
> Daejun

Hi Daejun


I only can give my tested-by tag since I preliminary tested it and it
works. However, as I said in the previous email, there is performance
downgrade comparing to the direct submission approach, also, we should
think about HPB 2.0.

Anyway, if Avri wants firstly make this series patch mainlined,
performance fixup later, this is fine to me. I can add and fix it
later.

BTW, you should rebase your this series set patch since there are
conflicts with latest Martin' git repo, after that, you can add my
tested-by tag.


Tested-by: Bean Huo <[e-mail]>


Thanks,
Bean

Daejun Park July 13, 2020, 10:25 a.m. UTC | #9

Hi Bean
> > Hi Bart,
> > 
> > > > Bart - how do you want to proceed?
> > > 
> > > Hi Avri and Daejun,
> > > 
> > > As far as I can see none of the five patches have Reviewed-by tags
> > > yet. I
> > > think that Martin expects formal reviews for this patch series from
> > > one or
> > > more reviewers who are not colleagues of the author of this patch
> > > series.
> > > 
> > > Note: recently I have been more busy than usual, hence the delayed
> > > reply.
> > 
> > Thank you for replying to the email even though you are busy.
> > 
> > Arvi, Bean - if patches looks ok, can this series have your reviewed-
> > by tag?
> > 
> > Thanks,
> > Daejun
> 
> Hi Daejun
> 
> 
> I only can give my tested-by tag since I preliminary tested it and it
> works. However, as I said in the previous email, there is performance
> downgrade comparing to the direct submission approach, also, we should
> think about HPB 2.0.

I plan to add your direct submission approach with HPB 2.0.

> Anyway, if Avri wants firstly make this series patch mainlined,
> performance fixup later, this is fine to me. I can add and fix it
> later.
> 
> BTW, you should rebase your this series set patch since there are
> conflicts with latest Martin' git repo, after that, you can add my
> tested-by tag.
> 
OK, I will. Thanks!

> Tested-by: Bean Huo <[e-mail]>
> 
> 
> Thanks,
> Bean
> 

Thanks,
Daejun