If no-one else objects, maybe you can submit your patches as non-RFC for review? Thanks, Avri > -----Original Message----- > From: Daejun Park <daejun7.park@xxxxxxxxxxx> > Sent: Tuesday, June 23, 2020 4:02 AM > To: Avri Altman <Avri.Altman@xxxxxxx>; jejb@xxxxxxxxxxxxx; > martin.petersen@xxxxxxxxxx; asutoshd@xxxxxxxxxxxxxx; > stanley.chu@xxxxxxxxxxxx; cang@xxxxxxxxxxxxxx; huobean@xxxxxxxxx; > bvanassche@xxxxxxx; tomas.winkler@xxxxxxxxx; ALIM AKHTAR > <alim.akhtar@xxxxxxxxxxx>; Daejun Park <daejun7.park@xxxxxxxxxxx> > Cc: linux-scsi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Sang-yoon Oh > <sangyoon.oh@xxxxxxxxxxx>; Sung-Jun Park > <sungjun07.park@xxxxxxxxxxx>; yongmyung lee > <ymhungry.lee@xxxxxxxxxxx>; Jinyoung CHOI <j- > young.choi@xxxxxxxxxxx>; Adel Choi <adel.choi@xxxxxxxxxxx>; BoRam > Shin <boram.shin@xxxxxxxxxxx> > Subject: [RFC PATCH v3 0/5] scsi: ufs: Add Host Performance Booster Support > > CAUTION: This email originated from outside of Western Digital. Do not click > on links or open attachments unless you recognize the sender and know that > the content is safe. > > > Changelog: > > 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/jeo > ng > > 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 | 23 +- > drivers/scsi/ufs/ufshcd.h | 3 + > drivers/scsi/ufs/ufshpb.c | 1996 ++++++++++++++++++++++++++++++++++++ > drivers/scsi/ufs/ufshpb.h | 234 +++++ > 9 files changed, 2494 insertions(+), 3 deletions(-) > 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
