Message ID | 20210202083007.104050-1-avri.altman@wdc.com |
---|---|
Headers | show |
Series | Add Host control mode to HPB | expand |
On Tue, 2021-02-02 at 10:29 +0200, Avri Altman wrote: > v1 -> v2: > - attend Greg's and Daejun's comments > - add patch 9 making host mode parameters configurable > - rebase on Daejun's v19 > > > The HPB spec defines 2 control modes - device control mode and host > control mode. In oppose to device control mode, in which the host > obey > to whatever recommendation received from the device - In host control > mode, the host uses its own algorithms to decide which regions should > be activated or inactivated. > > We kept the host managed heuristic simple and concise. > > Aside from adding a by-spec functionality, host control mode entails > some further potential benefits: makes the hpb logic transparent and > readable, while allow tuning / scaling its various parameters, and > utilize system-wide info to optimize HPB potential. Hi Avri In addition to the above advantage of HPB device mode, would you please share the performance comparison data with host mode? that will draw more attention, since you mentioned "you tested on Galaxy S20, and Xiaomi Mi10 pro", I think you have this kind of data. Your HPB host driver sits in the ufs driver. Since my HPB host mode driver is also implemented in the UFS driver layer, I did test my HPB driver between device mode and host mode. Saw there is an improvement, but not significant. If you can share your HPB drviver data, that will be awesome. Kind regards, Bean
On Fri, 2021-02-05 at 12:36 +0100, Bean Huo wrote: > > to whatever recommendation received from the device - In host > > control > > mode, the host uses its own algorithms to decide which regions > > should > > be activated or inactivated. > > > > We kept the host managed heuristic simple and concise. > > > > Aside from adding a by-spec functionality, host control mode > > entails > > some further potential benefits: makes the hpb logic transparent > > and > > readable, while allow tuning / scaling its various parameters, and > > utilize system-wide info to optimize HPB potential. > > Hi Avri > In addition to the above advantage of HPB device mode, would you > please > share the performance comparison data with host mode? that will draw > more attention, since you mentioned "you tested on Galaxy S20, and > Xiaomi Mi10 pro", I think you have this kind of data. > > Your HPB host driver sits in the ufs driver. Since my HPB host mode > driver is also implemented in the UFS driver layer, I did test my HPB > driver between device mode and host mode. Saw there is an > improvement, > but not significant. If you can share your HPB drviver data, that > will > be awesome. > > Kind regards, > Bean So sorry, there are several typos, easily confused you. correct them as below: Hi Avri In addition to the above advantage of HPB "host control mode", would you please share the performance comparison data with "device control mode"? that will draw more attention, since you mentioned "you tested on Galaxy S20, and Xiaomi Mi10 pro", I think you have this kind of data. Your HPB "host control mode" driver sits in the ufs driver. Since my HPB "host control mode" driver is also implemented in the UFS driver layer, I did test my HPB driver between device mode and host mode. Saw UFS HPB "host control mode" driver has performance gain comparing to HPB "device control mode" driver, but not significant. If you can share your HPB host control mode drviver data, that will be awesome. Kind regards, Bean
Hi Bean, > In addition to the above advantage of HPB "host control mode", would > you please share the performance comparison data with "device control > mode"? that will draw more attention, since you mentioned "you tested > on Galaxy S20, and Xiaomi Mi10 pro", I think you have this kind of > data. > > Your HPB "host control mode" driver sits in the ufs driver. Since my > HPB "host control mode" driver is also implemented in the UFS driver > layer, I did test my HPB driver between device mode and host mode. Saw > UFS HPB "host control mode" driver has performance gain comparing to > HPB "device control mode" driver, but not significant. If you can share > your HPB host control mode drviver data, that will be awesome. Host control mode wasn't standardized to overcome device mode performance. Instead, host control mode, entails several advantages comparing to device control mode: - Allow OEM vendors to have a unified HPB approach, with minor to null performance volatility across different storage vendors - Flexible and transparent logic which doesn’t requires device firmware changes. Hence, the discussion of host-control vs device control performance gain is chasing the red herring. Thanks, Avri