From: Lina Iyer <ilina@codeaurora.org>
To: Stephen Boyd <swboyd@chromium.org>
Cc: andy.gross@linaro.org, bjorn.andersson@linaro.org,
linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org,
rnayak@codeaurora.org, linux-kernel@vger.kernel.org,
linux-pm@vger.kernel.org, dianders@chromium.org,
mkshah@codeaurora.org,
"Raju P.L.S.S.S.N" <rplsssn@codeaurora.org>
Subject: Re: [PATCH 1/2] drivers: qcom: rpmh-rsc: simplify TCS locking
Date: Mon, 22 Jul 2019 13:46:24 -0600 [thread overview]
Message-ID: <20190722194624.GA11589@codeaurora.org> (raw)
In-Reply-To: <5d35fdfb.1c69fb81.5fafa.aaa9@mx.google.com>
On Mon, Jul 22 2019 at 12:18 -0600, Stephen Boyd wrote:
>Quoting Lina Iyer (2019-07-22 09:20:03)
>> On Fri, Jul 19 2019 at 12:20 -0600, Stephen Boyd wrote:
>> >Quoting Lina Iyer (2019-07-01 08:29:06)
>> >> From: "Raju P.L.S.S.S.N" <rplsssn@codeaurora.org>
>> >>
>> >> tcs->lock was introduced to serialize access with in TCS group. But
>> >> even without tcs->lock, drv->lock is serving the same purpose. So
>> >> use a single drv->lock.
>> >
>> >Isn't the downside now that we're going to be serializing access to the
>> >different TCSes when two are being written in parallel or waited on? I
>> >thought that was the whole point of splitting the lock into a TCS lock
>> >and a general "driver" lock that protects the global driver state vs.
>> >the specific TCS state.
>> >
>> Yes but we were holding the drv->lock as well as tcs->lock for the most
>> critical of the path anyways (writing to TCS). The added complexity
>> doesn't seem to help reduce the latency that it expected to reduce.
>
>Ok. That sort of information should be in the commit text to explain why
>it's not helping with reducing the latency or throughput of the API.
>
Will add.
--Lina
prev parent reply other threads:[~2019-07-22 19:46 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-01 15:29 [PATCH 1/2] drivers: qcom: rpmh-rsc: simplify TCS locking Lina Iyer
2019-07-01 15:29 ` [PATCH 2/2] drivers: qcom: rpmh-rsc: fix read back of trigger register Lina Iyer
2019-07-01 15:53 ` Lina Iyer
2019-07-19 18:22 ` Stephen Boyd
2019-07-22 15:51 ` Lina Iyer
2019-07-01 15:52 ` [PATCH 1/2] drivers: qcom: rpmh-rsc: simplify TCS locking Lina Iyer
2019-07-19 18:20 ` Stephen Boyd
2019-07-22 16:20 ` Lina Iyer
2019-07-22 18:18 ` Stephen Boyd
2019-07-22 19:46 ` Lina Iyer [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190722194624.GA11589@codeaurora.org \
--to=ilina@codeaurora.org \
--cc=andy.gross@linaro.org \
--cc=bjorn.andersson@linaro.org \
--cc=dianders@chromium.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=linux-soc@vger.kernel.org \
--cc=mkshah@codeaurora.org \
--cc=rnayak@codeaurora.org \
--cc=rplsssn@codeaurora.org \
--cc=swboyd@chromium.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).