From: Jani Nikula <jani.nikula@linux.intel.com>
To: Chris Wilson <chris@chris-wilson.co.uk>,
Dave Airlie <airlied@gmail.com>,
dri-devel@lists.freedesktop.org
Subject: Re: [PATCH] drm: micro optimise cache flushing
Date: Thu, 20 Sep 2012 13:02:03 +0300 [thread overview]
Message-ID: <87txut6mhw.fsf@intel.com> (raw)
In-Reply-To: <275ffc$6li573@fmsmga002.fm.intel.com>
On Wed, 19 Sep 2012, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> On Wed, 19 Sep 2012 11:12:41 +1000, Dave Airlie <airlied@gmail.com> wrote:
>> From: Dave Airlie <airlied@redhat.com>
>>
>> We hit this a lot with i915 and although we'd like to engineer things to hit
>> it a lot less, this commit at least makes it consume a few less cycles.
>>
>> from something containing
>> movzwl 0x0(%rip),%r10d
>> to
>> add %r8,%rdx
>>
>> I only noticed it while using perf to profile something else.
>>
>> Signed-off-by: Dave Airlie <airlied@redhat.com>
> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
>
> I would have thought this is something the compiler should, with the
> appropriate hints, be smart enough to decide for itself as boot_cpu_data
> should be constant once defined. *shrug*
Since it's not obvious the compiler isn't smart enough, should the code
carry a comment so we don't forget?
BR,
Jani.
prev parent reply other threads:[~2012-09-20 9:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-19 1:12 [PATCH] drm: micro optimise cache flushing Dave Airlie
2012-09-19 7:50 ` Chris Wilson
2012-09-20 10:02 ` Jani Nikula [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=87txut6mhw.fsf@intel.com \
--to=jani.nikula@linux.intel.com \
--cc=airlied@gmail.com \
--cc=chris@chris-wilson.co.uk \
--cc=dri-devel@lists.freedesktop.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.