Hi All,
I lost the only Android Tablet that I had to hack around and in the market
for new Android Tablet. Needs to be stuff I can buy personally, so Juno /
Vexpress is out the window.
What would you recommend I buy? Below are specific use cases
i. Work on NEON optimizations for Audio libraries (Vorbis, FLAC etc) in
**Android** context.
ii. So, would obviously like to have a reference Android baseline build
that is actively used in Linaro.
Is anyone in LMG using builds available for Nexus10
<http://releases.linaro.org/14.09/android/nexus10> and Nexus7
<http://releases.linaro.org/14.09/android/nexus7-2013> actively right now?
How official are these builds?
Regards,
Vish (Viswanath Puttagunta)
Cell: 972-342-0205
Technical Program Manager
Member Services, Linaro
Hi All,
Does any one have instructions to install Ubuntu natively on Samsung
Chromebook2 that worked for you?
Regards,
Vish (Viswanath Puttagunta)
Cell: 972-342-0205
Technical Program Manager
Member Services, Linaro
Hi,
I wanted to know about the impact of changing PAGE_ALLOC_COSTLY_ORDER value from 3 to 2.
This macro is defined in include/linux/mmzone.h
#define PAGE_ALLOC_COSTLY_ORDER 3
As I know this value should never be changed irrespective of the type of the system.
Is it good to change this value for RAM size: 512MB, 256MB or 128MB?
If anybody have changed this value and experience any kind of problem or benefits please let us know.
We noticed that for one of the Android product with 512MB RAM, the PAGE_ALLOC_COSTLY_ORDER was set to 2.
We could not figure out why this value was decreased from 3 to 2.
As per my analysis, I observed that kmalloc fails little early, if we change this value to 2.
This is also visible from the _slowpath_ in page_alloc.c
Apart from this we could not find any other impact.
If anybody is aware of any other impact, please let us know.
Thank you!
Regards,
Pintu Kumar
On Sun, Sep 14, 2014 at 12:36:43PM +0200, Christian König wrote:
> Yeah, right. Providing the fd to reassign to a fence would indeed reduce the
> create/close overhead.
>
> But it would still be more overhead than for example a simple on demand
> growing ring buffer which then uses 64bit sequence numbers in userspace to
> refer to a fence in the kernel.
>
> Apart from that I'm pretty sure that when we do the syncing completely in
> userspace we need more fences open at the same time than fds are available
> by default.
If you do the syncing completely in userspace you don't need kernel fences
at all. Kernel fences are only required if you sync with a different
process (where the pure userspace syncing might not work out) or with
different devices.
tbh I don't see any use-case at all where you'd need 10k such fences. That
means your driver gets to deal with 2 kinds of fences, but so be it. Since
not using fds for cross-device or cross-process syncing imo just doesn't
make sense, so that one pretty much will have to stick.
> As long as our internal handle or sequence based fence are easily
> convertible to a fence fd I actually don't really see a problem with that.
> Going to hack that approach into my prototype and then we can see how bad
> the code looks after all.
My plan for i915 is to start out with fd fences only, and once we have
some clarity on the exact requirements probably add some pure
userspace-controlled fences for tightly coupled stuff. Those might be
fully internal to the opencl userspace driver though and never get out of
there, ever.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
On Fri, 12 Sep 2014 18:08:23 +0200
Christian König <christian.koenig(a)amd.com> wrote:
> > As Daniel said using fd is most likely the way we want to do it but this
> > remains vague.
> Separating the discussion if it should be an fd or not. Using an fd
> sounds fine to me in general, but I have some concerns as well.
>
> For example what was the maximum number of opened FDs per process again?
> Could that become a problem? etc...
You can check out the i915 patches I posted if you want to see
examples. Max fds may be an issue if userspace doesn't clean up its
fences. The implementation is pretty easy with the stuff Maarten has
done recently.
The changes I still need to make to mine:
- sit on top of Chris's request/seqno changes (driver internals
really)
- switch over to execbuf as the main API on the render side (like
you're doing)
- add support for display and other timelines
As far as compat goes, I don't think it should be too hard. Even with
GPU scheduling, a given context's buffers should all be in-order with
respect to one another, so we ought to be able to mix & match clients
using explicit fencing and implicit fencing. Though in Mesa I still
haven't looked at how to handle server vs client side arb_sync with the
scheduler and explicit fencing in place; might need some extra work
there...
--
Jesse Barnes, Intel Open Source Technology Center
On Fri, Sep 12, 2014 at 05:58:09PM +0200, Christian König wrote:
> Am 12.09.2014 um 17:48 schrieb Jerome Glisse:
> >On Fri, Sep 12, 2014 at 05:42:57PM +0200, Christian König wrote:
> >>Am 12.09.2014 um 17:33 schrieb Jerome Glisse:
> >>>On Fri, Sep 12, 2014 at 11:25:12AM -0400, Alex Deucher wrote:
> >>>>On Fri, Sep 12, 2014 at 10:50 AM, Jerome Glisse <j.glisse(a)gmail.com> wrote:
> >>>>>On Fri, Sep 12, 2014 at 04:43:44PM +0200, Daniel Vetter wrote:
> >>>>>>On Fri, Sep 12, 2014 at 4:09 PM, Daniel Vetter <daniel(a)ffwll.ch> wrote:
> >>>>>>>On Fri, Sep 12, 2014 at 03:23:22PM +0200, Christian König wrote:
> >>>>>>>>Hello everyone,
> >>>>>>>>
> >>>>>>>>to allow concurrent buffer access by different engines beyond the multiple
> >>>>>>>>readers/single writer model that we currently use in radeon and other
> >>>>>>>>drivers we need some kind of synchonization object exposed to userspace.
> >>>>>>>>
> >>>>>>>>My initial patch set for this used (or rather abused) zero sized GEM buffers
> >>>>>>>>as fence handles. This is obviously isn't the best way of doing this (to
> >>>>>>>>much overhead, rather ugly etc...), Jerome commented on this accordingly.
> >>>>>>>>
> >>>>>>>>So what should a driver expose instead? Android sync points? Something else?
> >>>>>>>I think actually exposing the struct fence objects as a fd, using android
> >>>>>>>syncpts (or at least something compatible to it) is the way to go. Problem
> >>>>>>>is that it's super-hard to get the android guys out of hiding for this :(
> >>>>>>>
> >>>>>>>Adding a bunch of people in the hopes that something sticks.
> >>>>>>More people.
> >>>>>Just to re-iterate, exposing such thing while still using command stream
> >>>>>ioctl that use implicit synchronization is a waste and you can only get
> >>>>>the lowest common denominator which is implicit synchronization. So i do
> >>>>>not see the point of such api if you are not also adding a new cs ioctl
> >>>>>with explicit contract that it does not do any kind of synchronization
> >>>>>(it could be almost the exact same code modulo the do not wait for
> >>>>>previous cmd to complete).
> >>>>Our thinking was to allow explicit sync from a single process, but
> >>>>implicitly sync between processes.
> >>>This is a BIG NAK if you are using the same ioctl as it would mean you are
> >>>changing userspace API, well at least userspace expectation. Adding a new
> >>>cs flag might do the trick but it should not be about inter-process, or any
> >>>thing special, it's just implicit sync or no synchronization. Converting
> >>>userspace is not that much of a big deal either, it can be broken into
> >>>several step. Like mesa use explicit synchronization all time but ddx use
> >>>implicit.
> >>The thinking here is that we need to be backward compatible for DRI2/3 and
> >>support all kind of different use cases like old DDX and new Mesa, or old
> >>Mesa and new DDX etc...
> >>
> >>So for my prototype if the kernel sees any access of a BO from two different
> >>clients it falls back to the old behavior of implicit synchronization of
> >>access to the same buffer object. That might not be the fastest approach,
> >>but is as far as I can see conservative and so should work under all
> >>conditions.
> >>
> >>Apart from that the planning so far was that we just hide this feature
> >>behind a couple of command submission flags and new chunks.
> >Just to reproduce IRC discussion, i think it's a lot simpler and not that
> >complex. For explicit cs ioctl you do not wait for any previous fence of
> >any of the buffer referenced in the cs ioctl, but you still associate a
> >new fence with all the buffer object referenced in the cs ioctl. So if the
> >next ioctl is an implicit sync ioctl it will wait properly and synchronize
> >properly with previous explicit cs ioctl. Hence you can easily have a mix
> >in userspace thing is you only get benefit once enough of your userspace
> >is using explicit.
>
> Yes, that's exactly what my patches currently implement.
>
> The only difference is that by current planning I implemented it as a per BO
> flag for the command submission, but that was just for testing. Having a
> single flag to switch between implicit and explicit synchronization for
> whole CS IOCTL would do equally well.
Doing it per BO sounds bogus to me. But otherwise yes we are in agreement.
As Daniel said using fd is most likely the way we want to do it but this
remains vague.
>
> >Note that you still need a way to have explicit cs ioctl to wait on a
> >previos "explicit" fence so you need some api to expose fence per cs
> >submission.
>
> Exactly, that's what this mail thread is all about.
>
> As Daniel correctly noted you need something like a functionality to get a
> fence as the result of a command submission as well as pass in a list of
> fences to wait for before beginning a command submission.
>
> At least it looks like we are all on the same general line here, its just
> nobody has a good idea how the details should look like.
>
> Regards,
> Christian.
>
> >
> >Cheers,
> >Jérôme
> >
> >>Regards,
> >>Christian.
> >>
> >>>Cheers,
> >>>Jérôme
> >>>
> >>>>Alex
> >>>>
> >>>>>Also one thing that the Android sync point does not have, AFAICT, is a
> >>>>>way to schedule synchronization as part of a cs ioctl so cpu never have
> >>>>>to be involve for cmd stream that deal only one gpu (assuming the driver
> >>>>>and hw can do such trick).
> >>>>>
> >>>>>Cheers,
> >>>>>Jérôme
> >>>>>
> >>>>>>-Daniel
> >>>>>>--
> >>>>>>Daniel Vetter
> >>>>>>Software Engineer, Intel Corporation
> >>>>>>+41 (0) 79 365 57 48 - http://blog.ffwll.ch
> >>>>>_______________________________________________
> >>>>>dri-devel mailing list
> >>>>>dri-devel(a)lists.freedesktop.org
> >>>>>http://lists.freedesktop.org/mailman/listinfo/dri-devel
>
On Fri, Sep 12, 2014 at 05:42:57PM +0200, Christian König wrote:
> Am 12.09.2014 um 17:33 schrieb Jerome Glisse:
> >On Fri, Sep 12, 2014 at 11:25:12AM -0400, Alex Deucher wrote:
> >>On Fri, Sep 12, 2014 at 10:50 AM, Jerome Glisse <j.glisse(a)gmail.com> wrote:
> >>>On Fri, Sep 12, 2014 at 04:43:44PM +0200, Daniel Vetter wrote:
> >>>>On Fri, Sep 12, 2014 at 4:09 PM, Daniel Vetter <daniel(a)ffwll.ch> wrote:
> >>>>>On Fri, Sep 12, 2014 at 03:23:22PM +0200, Christian König wrote:
> >>>>>>Hello everyone,
> >>>>>>
> >>>>>>to allow concurrent buffer access by different engines beyond the multiple
> >>>>>>readers/single writer model that we currently use in radeon and other
> >>>>>>drivers we need some kind of synchonization object exposed to userspace.
> >>>>>>
> >>>>>>My initial patch set for this used (or rather abused) zero sized GEM buffers
> >>>>>>as fence handles. This is obviously isn't the best way of doing this (to
> >>>>>>much overhead, rather ugly etc...), Jerome commented on this accordingly.
> >>>>>>
> >>>>>>So what should a driver expose instead? Android sync points? Something else?
> >>>>>I think actually exposing the struct fence objects as a fd, using android
> >>>>>syncpts (or at least something compatible to it) is the way to go. Problem
> >>>>>is that it's super-hard to get the android guys out of hiding for this :(
> >>>>>
> >>>>>Adding a bunch of people in the hopes that something sticks.
> >>>>More people.
> >>>Just to re-iterate, exposing such thing while still using command stream
> >>>ioctl that use implicit synchronization is a waste and you can only get
> >>>the lowest common denominator which is implicit synchronization. So i do
> >>>not see the point of such api if you are not also adding a new cs ioctl
> >>>with explicit contract that it does not do any kind of synchronization
> >>>(it could be almost the exact same code modulo the do not wait for
> >>>previous cmd to complete).
> >>Our thinking was to allow explicit sync from a single process, but
> >>implicitly sync between processes.
> >This is a BIG NAK if you are using the same ioctl as it would mean you are
> >changing userspace API, well at least userspace expectation. Adding a new
> >cs flag might do the trick but it should not be about inter-process, or any
> >thing special, it's just implicit sync or no synchronization. Converting
> >userspace is not that much of a big deal either, it can be broken into
> >several step. Like mesa use explicit synchronization all time but ddx use
> >implicit.
>
> The thinking here is that we need to be backward compatible for DRI2/3 and
> support all kind of different use cases like old DDX and new Mesa, or old
> Mesa and new DDX etc...
>
> So for my prototype if the kernel sees any access of a BO from two different
> clients it falls back to the old behavior of implicit synchronization of
> access to the same buffer object. That might not be the fastest approach,
> but is as far as I can see conservative and so should work under all
> conditions.
>
> Apart from that the planning so far was that we just hide this feature
> behind a couple of command submission flags and new chunks.
Just to reproduce IRC discussion, i think it's a lot simpler and not that
complex. For explicit cs ioctl you do not wait for any previous fence of
any of the buffer referenced in the cs ioctl, but you still associate a
new fence with all the buffer object referenced in the cs ioctl. So if the
next ioctl is an implicit sync ioctl it will wait properly and synchronize
properly with previous explicit cs ioctl. Hence you can easily have a mix
in userspace thing is you only get benefit once enough of your userspace
is using explicit.
Note that you still need a way to have explicit cs ioctl to wait on a
previos "explicit" fence so you need some api to expose fence per cs
submission.
Cheers,
Jérôme
>
> Regards,
> Christian.
>
> >
> >Cheers,
> >Jérôme
> >
> >>Alex
> >>
> >>>Also one thing that the Android sync point does not have, AFAICT, is a
> >>>way to schedule synchronization as part of a cs ioctl so cpu never have
> >>>to be involve for cmd stream that deal only one gpu (assuming the driver
> >>>and hw can do such trick).
> >>>
> >>>Cheers,
> >>>Jérôme
> >>>
> >>>>-Daniel
> >>>>--
> >>>>Daniel Vetter
> >>>>Software Engineer, Intel Corporation
> >>>>+41 (0) 79 365 57 48 - http://blog.ffwll.ch
> >>>_______________________________________________
> >>>dri-devel mailing list
> >>>dri-devel(a)lists.freedesktop.org
> >>>http://lists.freedesktop.org/mailman/listinfo/dri-devel
>