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From: Laura Abbott <labbott@redhat.com>
To: "Andrew F. Davis" <afd@ti.com>, Brian Starkey <Brian.Starkey@arm.com>
Cc: "Sumit Semwal" <sumit.semwal@linaro.org>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Arve Hjønnevåg" <arve@android.com>,
	"devel@driverdev.osuosl.org" <devel@driverdev.osuosl.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>, nd <nd@arm.com>
Subject: Re: [PATCH 11/14] staging: android: ion: Allow heap name to be null
Date: Fri, 18 Jan 2019 11:53:33 -0800	[thread overview]
Message-ID: <042dd3b1-9a41-2a76-270d-1c992d782c40@redhat.com> (raw)
In-Reply-To: <39453e0a-2db8-3a59-1909-e02caa9afa31@ti.com>

On 1/16/19 9:12 AM, Andrew F. Davis wrote:
> On 1/16/19 9:28 AM, Brian Starkey wrote:
>> Hi Andrew,
>>
>> On Fri, Jan 11, 2019 at 12:05:20PM -0600, Andrew F. Davis wrote:
>>> The heap name can be used for debugging but otherwise does not seem
>>> to be required and no other part of the code will fail if left NULL
>>> except here. We can make it required and check for it at some point,
>>> for now lets just prevent this from causing a NULL pointer exception.
>>
>> I'm not so keen on this one. In the "new" API with heap querying, the
>> name string is the only way to identify the heap. I think Laura
>> mentioned at XDC2017 that it was expected that userspace should use
>> the strings to find the heap they want.
>>
> 
> Right now the names are only for debug. I accidentally left the name
> null once and got a kernel crash. This is the only spot where it is
> needed so I fixed it up. The other option is to make the name mandatory
> and properly error out, I don't want to do that right now until the
> below discussion is had to see if names really do matter or not.
> 

Yes, the heap names are part of the query API and are the expected
way to identify individual heaps for the API at the moment so having
a null heap name is incorrect. The heap name seemed like the best way
to identify heaps to userspace but if you have an alternative proposal
I'd be interested.

Thanks,
Laura

> 



WARNING: multiple messages have this Message-ID (diff)
From: Laura Abbott <labbott@redhat.com>
To: "Andrew F. Davis" <afd@ti.com>, Brian Starkey <Brian.Starkey@arm.com>
Cc: "devel@driverdev.osuosl.org" <devel@driverdev.osuosl.org>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	"Arve Hjønnevåg" <arve@android.com>, nd <nd@arm.com>
Subject: Re: [PATCH 11/14] staging: android: ion: Allow heap name to be null
Date: Fri, 18 Jan 2019 11:53:33 -0800	[thread overview]
Message-ID: <042dd3b1-9a41-2a76-270d-1c992d782c40@redhat.com> (raw)
In-Reply-To: <39453e0a-2db8-3a59-1909-e02caa9afa31@ti.com>

On 1/16/19 9:12 AM, Andrew F. Davis wrote:
> On 1/16/19 9:28 AM, Brian Starkey wrote:
>> Hi Andrew,
>>
>> On Fri, Jan 11, 2019 at 12:05:20PM -0600, Andrew F. Davis wrote:
>>> The heap name can be used for debugging but otherwise does not seem
>>> to be required and no other part of the code will fail if left NULL
>>> except here. We can make it required and check for it at some point,
>>> for now lets just prevent this from causing a NULL pointer exception.
>>
>> I'm not so keen on this one. In the "new" API with heap querying, the
>> name string is the only way to identify the heap. I think Laura
>> mentioned at XDC2017 that it was expected that userspace should use
>> the strings to find the heap they want.
>>
> 
> Right now the names are only for debug. I accidentally left the name
> null once and got a kernel crash. This is the only spot where it is
> needed so I fixed it up. The other option is to make the name mandatory
> and properly error out, I don't want to do that right now until the
> below discussion is had to see if names really do matter or not.
> 

Yes, the heap names are part of the query API and are the expected
way to identify individual heaps for the API at the moment so having
a null heap name is incorrect. The heap name seemed like the best way
to identify heaps to userspace but if you have an alternative proposal
I'd be interested.

Thanks,
Laura

> 


_______________________________________________
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dri-devel@lists.freedesktop.org
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  reply	other threads:[~2019-01-18 19:53 UTC|newest]

Thread overview: 125+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-11 18:05 [PATCH 00/14] Misc ION cleanups and adding unmapped heap Andrew F. Davis
2019-01-11 18:05 ` Andrew F. Davis
2019-01-11 18:05 ` [PATCH 01/14] staging: android: ion: Add proper header information Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-11 18:05 ` [PATCH 02/14] staging: android: ion: Remove empty ion_ioctl_dir() function Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-11 18:05 ` [PATCH 03/14] staging: android: ion: Merge ion-ioctl.c into ion.c Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-11 18:05 ` [PATCH 04/14] staging: android: ion: Remove leftover comment Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-11 18:05 ` [PATCH 05/14] staging: android: ion: Remove struct ion_platform_heap Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-11 18:05 ` [PATCH 06/14] staging: android: ion: Fixup some white-space issues Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-11 18:05 ` [PATCH 07/14] staging: android: ion: Sync comment docs with struct ion_buffer Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-11 18:05 ` [PATCH 08/14] staging: android: ion: Remove base from ion_carveout_heap Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-11 18:05 ` [PATCH 09/14] staging: android: ion: Remove base from ion_chunk_heap Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-11 18:05 ` [PATCH 10/14] staging: android: ion: Remove unused headers Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-11 18:05 ` [PATCH 11/14] staging: android: ion: Allow heap name to be null Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-16 15:28   ` Brian Starkey
2019-01-16 17:12     ` Andrew F. Davis
2019-01-16 17:12       ` Andrew F. Davis
2019-01-18 19:53       ` Laura Abbott [this message]
2019-01-18 19:53         ` Laura Abbott
2019-01-21 14:30         ` Andrew F. Davis
2019-01-11 18:05 ` [PATCH 12/14] staging: android: ion: Declare helpers for carveout and chunk heaps Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-18  9:59   ` Greg Kroah-Hartman
2019-01-18  9:59     ` Greg Kroah-Hartman
2019-01-18 16:09     ` Andrew F. Davis
2019-01-18 16:09       ` Andrew F. Davis
2019-01-18 19:54     ` Laura Abbott
2019-01-18 19:54       ` Laura Abbott
2019-01-11 18:05 ` [PATCH 13/14] staging: android: ion: Do not sync CPU cache on map/unmap Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-14 17:13   ` Liam Mark
2019-01-14 17:13     ` Liam Mark
2019-01-15 15:44     ` Andrew F. Davis
2019-01-15 17:45       ` Liam Mark
2019-01-15 18:38         ` Andrew F. Davis
2019-01-15 18:38           ` Andrew F. Davis
2019-01-15 18:40           ` Andrew F. Davis
2019-01-15 18:40             ` Andrew F. Davis
2019-01-16 15:19             ` Brian Starkey
2019-01-16 15:19               ` Brian Starkey
2019-01-16 17:05               ` Andrew F. Davis
2019-01-16 17:05                 ` Andrew F. Davis
2019-01-16 22:54                 ` Liam Mark
2019-01-17 16:25                   ` Andrew F. Davis
2019-01-17 16:25                     ` Andrew F. Davis
2019-01-18  1:11                     ` Liam Mark
2019-01-18 17:16                       ` Andrew F. Davis
2019-01-18 17:16                         ` Andrew F. Davis
2019-01-21 11:22                         ` Brian Starkey
2019-01-21 11:22                           ` Brian Starkey
2019-01-21 21:21                           ` Andrew F. Davis
2019-01-21 21:21                             ` Andrew F. Davis
2019-01-22 17:33                             ` Sumit Semwal
2019-01-22 17:33                               ` Sumit Semwal
2019-01-23 16:51                               ` Andrew F. Davis
2019-01-23 16:51                                 ` Andrew F. Davis
2019-01-23 17:11                                 ` Brian Starkey
2019-01-24 16:04                                   ` Andrew F. Davis
2019-01-24 16:04                                     ` Andrew F. Davis
2019-01-24 16:44                                     ` Brian Starkey
2019-01-24 16:44                                       ` Brian Starkey
2019-02-19 21:37                                       ` Laura Abbott
2019-01-23  3:23                             ` Sumit Semwal
2019-01-23 17:09                               ` Andrew F. Davis
2019-01-23 17:09                                 ` Andrew F. Davis
2019-01-22 22:56                           ` Liam Mark
2019-01-22 22:56                             ` Liam Mark
2019-01-21 20:11                         ` Liam Mark
2019-01-15 19:05           ` Laura Abbott
2019-01-15 19:05             ` Laura Abbott
2019-01-16 16:17             ` Andrew F. Davis
2019-01-16 16:17               ` Andrew F. Davis
2019-01-16 22:48               ` Liam Mark
2019-01-17 16:13                 ` Andrew F. Davis
2019-01-17 16:13                   ` Andrew F. Davis
2019-01-18  1:04                   ` Liam Mark
2019-01-18  1:04                     ` Liam Mark
2019-01-18 16:50                     ` Andrew F. Davis
2019-01-18 16:50                       ` Andrew F. Davis
2019-01-18 21:43                       ` Liam Mark
2019-01-18 21:43                         ` Liam Mark
2019-01-21 15:15                         ` Andrew F. Davis
2019-01-21 20:04                           ` Liam Mark
2019-01-18 20:31                   ` Laura Abbott
2019-01-18 20:31                     ` Laura Abbott
2019-01-18 20:43                     ` Andrew F. Davis
2019-01-18 20:43                       ` Andrew F. Davis
2019-01-18 20:46                       ` Laura Abbott
2019-01-18 20:46                         ` Laura Abbott
2019-01-19 10:11                     ` Christoph Hellwig
2019-01-17  9:02               ` Christoph Hellwig
2019-01-11 18:05 ` [PATCH 14/14] staging: android: ion: Add UNMAPPED heap type and helper Andrew F. Davis
2019-01-11 18:05   ` Andrew F. Davis
2019-01-15  2:32   ` Laura Abbott
2019-01-15  2:32     ` Laura Abbott
2019-01-15 15:58     ` Andrew F. Davis
2019-01-15 15:58       ` Andrew F. Davis
2019-01-15 18:43       ` Laura Abbott
2019-01-15 19:11         ` Laura Abbott
2019-01-15 19:11           ` Laura Abbott
2019-01-16 16:18           ` Andrew F. Davis
2019-01-16 16:18             ` Andrew F. Davis
2019-01-15  2:39 ` [PATCH 00/14] Misc ION cleanups and adding unmapped heap Laura Abbott
2019-01-15  2:39   ` Laura Abbott
2019-01-15 17:47   ` Andrew F. Davis
2019-01-15 17:47     ` Andrew F. Davis
2019-01-15 18:58     ` Laura Abbott
2019-01-15 18:58       ` Laura Abbott
2019-01-16 16:05       ` Andrew F. Davis
2019-01-16 16:05         ` Andrew F. Davis
2019-01-18 20:19         ` Laura Abbott
2019-01-21 14:58           ` Andrew F. Davis
2019-01-21 14:58             ` Andrew F. Davis
2019-01-18  9:56 ` Greg Kroah-Hartman
2019-01-18  9:56   ` Greg Kroah-Hartman

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