linux-kernel - Re: [PATCH 2/4] mmc: Add virtual command queue support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 9 Sep 2019 20:16:43 +0800
From:   Baolin Wang <baolin.wang@...aro.org>
To:     Adrian Hunter <adrian.hunter@...el.com>
Cc:     Ulf Hansson <ulf.hansson@...aro.org>, riteshh@...eaurora.org,
        asutoshd@...eaurora.org, Orson Zhai <orsonzhai@...il.com>,
        Chunyan Zhang <zhang.lyra@...il.com>,
        Arnd Bergmann <arnd@...db.de>,
        Linus Walleij <linus.walleij@...aro.org>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        linux-mmc <linux-mmc@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/4] mmc: Add virtual command queue support

Hi Adrian,

On Mon, 9 Sep 2019 at 20:02, Adrian Hunter <adrian.hunter@...el.com> wrote:
>
> On 6/09/19 6:52 AM, Baolin Wang wrote:
> > Now the MMC read/write stack will always wait for previous request is
> > completed by mmc_blk_rw_wait(), before sending a new request to hardware,
> > or queue a work to complete request, that will bring context switching
> > overhead, especially for high I/O per second rates, to affect the IO
> > performance.
> >
> > Thus this patch introduces virtual command queue interface, which is
> > similar with the hardware command queue engine's idea, that can remove
> > the context switching.
>
> CQHCI is a hardware interface for eMMC's that support command queuing.  What
> you are doing is a software issue queue, unrelated to CQHCI.  I think you

Yes.

> should avoid all reference to CQHCI i.e. call it something else.

Since its process is similar with CQHCI and re-use the CQHCI's
interfaces, I called it virtual command queue. I am not sure what else
name is better, any thoughts? VCQHCI? Thanks.

--
Baolin Wang
Best Regards