Hi All, I want to know how to improve this patch. Could you review this patch? Martin, Can we move forward with this one? Thanks, Daejun > Changelog: > > v10 -> v11 > Add a newline at end the last line on Kconfig file. > > v9 -> v10 > 1. Fix 64-bit division error > 2. Fix problems commentted in Bart's review. > > v8 -> v9 > 1. Change sysfs initialization. > 2. Change reading descriptor during HPB initialization > 3. Fix problems commentted in Bart's review. > 4. Change base commit from 5.9/scsi-queue to 5.10/scsi-queue. > > v7 -> v8 > Remove wrongly added tags. > > v6 -> v7 > 1. Remove UFS feature layer. > 2. Cleanup for sparse error. > > v5 -> v6 > Change base commit to b53293fa662e28ae0cdd40828dc641c09f133405 > > 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 3 parts to support HPB feature. > > 1) HPB probe and initialization process > 2) READ -> HPB READ using cached map information > 3) L2P (logical to physical) map management > > 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. > > The HPB manages the L2P map using information received from the > device. For active sub-region, the HPB caches through ufshpb_map > request. For the in-active region, the HPB 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 (4): > scsi: ufs: Add HPB feature related parameters > scsi: ufs: Introduce HPB feature > scsi: ufs: L2P map management for HPB read > scsi: ufs: Prepare HPB read for cached sub-region > > drivers/scsi/ufs/Kconfig | 10 + > drivers/scsi/ufs/Makefile | 1 + > drivers/scsi/ufs/ufs.h | 47 + > drivers/scsi/ufs/ufshcd.c | 60 ++ > drivers/scsi/ufs/ufshcd.h | 23 +- > drivers/scsi/ufs/ufshpb.c | 1845 ++++++++++++++++++++++++++++++++++++++++ > drivers/scsi/ufs/ufshpb.h | 229 +++++ > 7 files changed, 2214 insertions(+), 1 deletion(-) > created mode 100644 drivers/scsi/ufs/ufshpb.c > created mode 100644 drivers/scsi/ufs/ufshpb.h
