On Thu, Apr 16, 2020 at 10:31:21PM +0200, huobean@xxxxxxxxx wrote: > From: Bean Huo <beanhuo@xxxxxxxxxx> > > Hi, > I disclose my development/changes on UFS HPB (UFS Host Performance Booster) to > the community, as this would enable more UFS developers to test and start an > iterative review and update process. > > The HPB is defined in Jedec Standard Universal Flash (UFS) Host Performance > Booster (HPB) Extension Version 1.0, which is designed to improve read > performance by utilizing the host side memory. Based on our testing, the HPB > can increase the random read performance by up to about 46% in the random read. > > The original HPB driver is from [1]. Based on it, I did optimizations, > simplifications, fixed reliability issues, implemented HPB host control mode > and make it much more readable. which's pushed to here [2] as V1. > > To avoid touching the traditional SCSI core, the HPB driver in this series HPB > patch chooses to develop under SCSI sub-system layer, and sits the same layer > with UFSHCD. At the same time, to minimize changes to UFSHCD driver, the HPB > driver submits its HPB READ BUFFER and HPB WRITE BUFFER requests to the scsi > device->request_queueu to execute, rather than that directly go through > raw UPIU request path. This feature is completley broken, and rather dangerous due to feeding "physical" addresses looked up by the host in. I do not think we should support something that broken in Linux. Independent of that using two requests in the I/O path is not going to fly either. The whole thing seems like an exercise in benchmarketing.
