From: Laura Abbott <labbott@redhat.com>
To: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: "Daniel Vetter" <daniel.vetter@ffwll.ch>,
"Mark Brown" <broonie@kernel.org>,
"Michal Hocko" <mhocko@kernel.org>,
"Sumit Semwal" <sumit.semwal@linaro.org>,
"Riley Andrews" <riandrews@android.com>,
"Arve Hjønnevåg" <arve@android.com>,
"Rom Lemarchand" <romlem@google.com>,
devel@driverdev.osuosl.org,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"linaro-mm-sig@lists.linaro.org" <linaro-mm-sig@lists.linaro.org>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
"dri-devel@lists.freedesktop.org"
<dri-devel@lists.freedesktop.org>,
"Brian Starkey" <brian.starkey@arm.com>,
"Daniel Vetter" <daniel.vetter@intel.com>,
"Linux MM" <linux-mm@kvack.org>
Subject: Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging
Date: Tue, 14 Mar 2017 12:45:02 -0700 [thread overview]
Message-ID: <38d38ae5-d897-1c98-4d36-c3b16a92bfee@redhat.com> (raw)
In-Reply-To: <CA+M3ks5AyVN1hn=FCRx7sy-3B=VujEBL4G4tWy6opifkKTD8=w@mail.gmail.com>
On 03/14/2017 07:47 AM, Benjamin Gaignard wrote:
> 2017-03-13 22:09 GMT+01:00 Laura Abbott <labbott@redhat.com>:
>> On 03/12/2017 12:05 PM, Daniel Vetter wrote:
>>> On Sun, Mar 12, 2017 at 2:34 PM, Benjamin Gaignard
>>> <benjamin.gaignard@linaro.org> wrote:
>>>> 2017-03-09 18:38 GMT+01:00 Laura Abbott <labbott@redhat.com>:
>>>>> On 03/09/2017 02:00 AM, Benjamin Gaignard wrote:
>>>>>> 2017-03-06 17:04 GMT+01:00 Daniel Vetter <daniel@ffwll.ch>:
>>>>>>> On Mon, Mar 06, 2017 at 11:58:05AM +0100, Mark Brown wrote:
>>>>>>>> On Mon, Mar 06, 2017 at 11:40:41AM +0100, Daniel Vetter wrote:
>>>>>>>>
>>>>>>>>> No one gave a thing about android in upstream, so Greg KH just dumped it
>>>>>>>>> all into staging/android/. We've discussed ION a bunch of times, recorded
>>>>>>>>> anything we'd like to fix in staging/android/TODO, and Laura's patch
>>>>>>>>> series here addresses a big chunk of that.
>>>>>>>>
>>>>>>>>> This is pretty much the same approach we (gpu folks) used to de-stage the
>>>>>>>>> syncpt stuff.
>>>>>>>>
>>>>>>>> Well, there's also the fact that quite a few people have issues with the
>>>>>>>> design (like Laurent). It seems like a lot of them have either got more
>>>>>>>> comfortable with it over time, or at least not managed to come up with
>>>>>>>> any better ideas in the meantime.
>>>>>>>
>>>>>>> See the TODO, it has everything a really big group (look at the patch for
>>>>>>> the full Cc: list) figured needs to be improved at LPC 2015. We don't just
>>>>>>> merge stuff because merging stuff is fun :-)
>>>>>>>
>>>>>>> Laurent was even in that group ...
>>>>>>> -Daniel
>>>>>>
>>>>>> For me those patches are going in the right direction.
>>>>>>
>>>>>> I still have few questions:
>>>>>> - since alignment management has been remove from ion-core, should it
>>>>>> be also removed from ioctl structure ?
>>>>>
>>>>> Yes, I think I'm going to go with the suggestion to fixup the ABI
>>>>> so we don't need the compat layer and as part of that I'm also
>>>>> dropping the align argument.
>>>>>
>>>>>> - can you we ride off ion_handle (at least in userland) and only
>>>>>> export a dma-buf descriptor ?
>>>>>
>>>>> Yes, I think this is the right direction given we're breaking
>>>>> everything anyway. I was debating trying to keep the two but
>>>>> moving to only dma bufs is probably cleaner. The only reason
>>>>> I could see for keeping the handles is running out of file
>>>>> descriptors for dma-bufs but that seems unlikely.
>>>>>>
>>>>>> In the future how can we add new heaps ?
>>>>>> Some platforms have very specific memory allocation
>>>>>> requirements (just have a look in the number of gem custom allocator in drm)
>>>>>> Do you plan to add heap type/mask for each ?
>>>>>
>>>>> Yes, that was my thinking.
>>>>
>>>> My concern is about the policy to adding heaps, will you accept
>>>> "customs" heap per
>>>> platforms ? per devices ? or only generic ones ?
>>>> If you are too strict, we will have lot of out-of-tree heaps and if
>>>> you accept of of them
>>>> it will be a nightmare to maintain....
>>>
>>> I think ion should expose any heap that's also directly accessible to
>>> devices using dma_alloc(_coherent). That should leave very few things
>>> left, like your SMA heap.
>>>
>>>> Another point is how can we put secure rules (like selinux policy) on
>>>> heaps since all the allocations
>>>> go to the same device (/dev/ion) ? For example, until now, in Android
>>>> we have to give the same
>>>> access rights to all the process that use ION.
>>>> It will become problem when we will add secure heaps because we won't
>>>> be able to distinguish secure
>>>> processes to standard ones or set specific policy per heaps.
>>>> Maybe I'm wrong here but I have never see selinux policy checking an
>>>> ioctl field but if that
>>>> exist it could be a solution.
>>>
>>> Hm, we might want to expose all the heaps as individual
>>> /dev/ion_$heapname nodes? Should we do this from the start, since
>>> we're massively revamping the uapi anyway (imo not needed, current
>>> state seems to work too)?
>>> -Daniel
>>>
>>
>> I thought about that. One advantage with separate /dev/ion_$heap
>
> Should we use /devi/ion/$heap instead of /dev/ion_$heap ?
> I think it would be easier for user to look into one directory rather
> then in whole /dev to find the heaps
>
If we decide to move away from /dev/ion we can consider it.
>> is that we don't have to worry about a limit of 32 possible
>> heaps per system (32-bit heap id allocation field). But dealing
>> with an ioctl seems easier than names. Userspace might be less
>> likely to hardcode random id numbers vs. names as well.
>
> In the futur I think that heap type will be replaced by a "get caps"
> ioctl which will
> describe heap capabilities. At least that is my understanding of kernel part
> of "unix memory allocator" project
>
I don't think it will be completely replaced. A heap can have multiple
capabilities so I suspect there will need to be some cap -> allocation
instance translation. Of course all this is wild speculation since
much of the unix memory allocator isn't well defined yet.
Thanks,
Laura
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-03-14 19:45 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-02 21:44 [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Laura Abbott
2017-03-02 21:44 ` [RFC PATCH 01/12] staging: android: ion: Remove dmap_cnt Laura Abbott
2017-03-02 21:44 ` [RFC PATCH 02/12] staging: android: ion: Remove alignment from allocation field Laura Abbott
2017-03-02 21:44 ` [RFC PATCH 03/12] staging: android: ion: Duplicate sg_table Laura Abbott
2017-03-03 8:18 ` Hillf Danton
2017-03-03 18:41 ` Laura Abbott
2017-03-02 21:44 ` [RFC PATCH 04/12] staging: android: ion: Call dma_map_sg for syncing and mapping Laura Abbott
2017-03-03 11:04 ` Dan Carpenter
2017-03-03 11:58 ` Eric Engestrom
2017-03-03 16:37 ` Laurent Pinchart
2017-03-03 18:40 ` Laura Abbott
2017-03-02 21:44 ` [RFC PATCH 05/12] staging: android: ion: Remove page faulting support Laura Abbott
2017-03-02 21:44 ` [RFC PATCH 06/12] staging: android: ion: Remove crufty cache support Laura Abbott
2017-03-03 9:56 ` Daniel Vetter
2017-03-03 16:39 ` Laurent Pinchart
2017-03-03 18:46 ` Laura Abbott
2017-03-06 10:29 ` Daniel Vetter
2017-03-06 17:00 ` Emil Velikov
2017-03-06 19:20 ` Laura Abbott
2017-03-02 21:44 ` [RFC PATCH 07/12] staging: android: ion: Remove old platform support Laura Abbott
2017-03-03 10:31 ` Daniel Vetter
2017-03-02 21:44 ` [RFC PATCH 08/12] cma: Store a name in the cma structure Laura Abbott
2017-03-10 8:53 ` Sumit Semwal
2017-03-17 18:02 ` Laura Abbott
2017-03-02 21:44 ` [RFC PATCH 09/12] cma: Introduce cma_for_each_area Laura Abbott
2017-03-02 21:44 ` [RFC PATCH 10/12] staging: android: ion: Use CMA APIs directly Laura Abbott
2017-03-03 16:41 ` Laurent Pinchart
2017-03-03 18:50 ` Laura Abbott
2017-03-06 10:32 ` Daniel Vetter
2017-03-06 13:43 ` Laurent Pinchart
2017-03-06 15:52 ` Daniel Vetter
2017-03-06 19:14 ` Laura Abbott
2017-03-02 21:44 ` [RFC PATCH 11/12] staging: android: ion: Make Ion heaps selectable Laura Abbott
2017-03-03 10:33 ` Daniel Vetter
2017-03-03 19:10 ` Laura Abbott
2017-03-02 21:44 ` [RFC PATCH 12/12] staging; android: ion: Enumerate all available heaps Laura Abbott
2017-03-03 10:39 ` Daniel Vetter
2017-03-03 10:04 ` [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Daniel Vetter
2017-03-03 10:27 ` Daniel Vetter
2017-03-03 12:54 ` Benjamin Gaignard
2017-03-03 16:45 ` Laurent Pinchart
2017-03-03 19:16 ` Laura Abbott
2017-03-06 10:38 ` Daniel Vetter
2017-03-06 15:02 ` Laurent Pinchart
2017-03-06 16:01 ` Daniel Vetter
2017-03-03 13:29 ` Michal Hocko
2017-03-03 17:37 ` Laura Abbott
2017-03-06 7:42 ` Michal Hocko
2017-03-06 10:40 ` Daniel Vetter
2017-03-06 10:58 ` Mark Brown
2017-03-06 16:04 ` Daniel Vetter
2017-03-09 10:00 ` Benjamin Gaignard
2017-03-09 17:38 ` Laura Abbott
2017-03-10 10:31 ` Brian Starkey
2017-03-10 11:46 ` Robin Murphy
2017-03-10 14:27 ` Brian Starkey
2017-03-10 16:46 ` Laura Abbott
2017-03-10 12:40 ` Daniel Vetter
2017-03-10 13:56 ` Rob Clark
2017-03-12 13:34 ` Benjamin Gaignard
2017-03-12 19:05 ` Daniel Vetter
2017-03-13 21:09 ` Laura Abbott
2017-03-13 21:29 ` Rob Clark
2017-03-13 21:59 ` Laura Abbott
2017-03-14 14:47 ` Benjamin Gaignard
2017-03-14 19:45 ` Laura Abbott [this message]
2017-03-14 20:28 ` Nicolas Dufresne
2017-03-13 10:54 ` Brian Starkey
2017-03-13 13:21 ` Mark Brown
2017-03-13 21:45 ` Laura Abbott
2017-03-13 21:29 ` Laura Abbott
2017-03-06 13:34 ` Michal Hocko
2017-03-03 16:25 ` Laurent Pinchart
2017-03-03 19:14 ` Laura Abbott
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=38d38ae5-d897-1c98-4d36-c3b16a92bfee@redhat.com \
--to=labbott@redhat.com \
--cc=arve@android.com \
--cc=benjamin.gaignard@linaro.org \
--cc=brian.starkey@arm.com \
--cc=broonie@kernel.org \
--cc=daniel.vetter@ffwll.ch \
--cc=daniel.vetter@intel.com \
--cc=devel@driverdev.osuosl.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=gregkh@linuxfoundation.org \
--cc=linaro-mm-sig@lists.linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=riandrews@android.com \
--cc=romlem@google.com \
--cc=sumit.semwal@linaro.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).