From: "Murthy, Arun R" <arun.r.murthy@gmail.com>
To: Chris Wilson <chris@chris-wilson.co.uk>,
Arun R Murthy <arun.r.murthy@intel.com>,
daniel.vetter@ffwll.ch, jani.nikula@linux.intel.com,
intel-gfx@lists.freedesktop.org, airlied@linux.ie
Subject: Re: [PATCH v3] drm/i915: use hrtimer in wait for vblank
Date: Tue, 25 Mar 2014 14:31:24 +0530 [thread overview]
Message-ID: <533145E4.6060300@gmail.com> (raw)
In-Reply-To: <20140325073029.GV4366@nuc-i3427.alporthouse.com>
On Tuesday 25 March 2014 01:00 PM, Chris Wilson wrote:
> On Tue, Mar 25, 2014 at 11:29:02AM +0530, Arun R Murthy wrote:
>> In wait for vblank use usleep_range, which will use hrtimers instead of
>> msleep. Using msleep(1~20) there are more chances of sleeping for 20ms.
>> Using usleep_range uses hrtimers and hence are precise, worst case will
>> trigger an interrupt at the higher/max timeout.
>>
>> Change-log: On replacing msleep(1) with usleep_range(1000, 2000) we have
>> noticed the time consumed by wait for vblank is ~4ms to ~17ms.
>>
>> Change-Id: I6672e5697b01987a6d069ab06e76d97287b1f7ae
>> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> No. I feel strongly that we do not want more wait_for_X() with strange
> semantics.
> http://sweng.the-davies.net/Home/rustys-api-design-manifesto
Will revert this additional wait_for_X.
Will update the existing _wait_for as per the kernel documentation for
timers.
Thanks and Regards,
Arun R Murthy
------------------
prev parent reply other threads:[~2014-03-25 9:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-25 5:59 [PATCH v3] drm/i915: use hrtimer in wait for vblank Arun R Murthy
2014-03-25 7:30 ` Chris Wilson
2014-03-25 9:01 ` Murthy, Arun R [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=533145E4.6060300@gmail.com \
--to=arun.r.murthy@gmail.com \
--cc=airlied@linux.ie \
--cc=arun.r.murthy@intel.com \
--cc=chris@chris-wilson.co.uk \
--cc=daniel.vetter@ffwll.ch \
--cc=intel-gfx@lists.freedesktop.org \
--cc=jani.nikula@linux.intel.com \
/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