[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <SN6PR04MB4640BDF845EE64733E5F626BFCD30@SN6PR04MB4640.namprd04.prod.outlook.com>
Date: Thu, 23 Apr 2020 08:26:27 +0000
From: Avri Altman <Avri.Altman@....com>
To: "Bean Huo (beanhuo)" <beanhuo@...ron.com>,
"hch@...radead.org" <hch@...radead.org>
CC: "alim.akhtar@...sung.com" <alim.akhtar@...sung.com>,
"asutoshd@...eaurora.org" <asutoshd@...eaurora.org>,
"jejb@...ux.ibm.com" <jejb@...ux.ibm.com>,
"martin.petersen@...cle.com" <martin.petersen@...cle.com>,
"stanley.chu@...iatek.com" <stanley.chu@...iatek.com>,
"bvanassche@....org" <bvanassche@....org>,
"tomas.winkler@...el.com" <tomas.winkler@...el.com>,
"cang@...eaurora.org" <cang@...eaurora.org>,
"linux-scsi@...r.kernel.org" <linux-scsi@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [EXT] Re: [PATCH v2 0/5] UFS Host Performance Booster (HPB v1.0)
driver
>
> Hi, Christoph
> Thanks for your feedback.
>
> > > 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
> > > device->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.
> >
>
> It Is not plain physical address, has been encrypted before loading from UFS
> to
> HPB memory, I think we don't worry about its safety.
>
> > 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.
>
> I agree with you. This is my major concern. I have been thinking about HPB
> implementation in SCSI layer.
> That will let SCSI layer manage HPB by calling UFS helper interface.
> If you don't consider UFS HPB is an idiot design, I want to change in another
> version. Firstly, we really
> want to hear your suggestion.
> Thanks,
>
> //Bean
If indeed this will move forward, please publish your patches as a RFC,
To allow competing approaches to be published as well.
Thanks,
Avri
Powered by blists - more mailing lists