linux-kernel - Re: [PATCHv2 1/4] staging: android: ion: Drop heap type masks

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Date:   Fri, 2 Sep 2016 12:36:25 -0700
From:   Laura Abbott <labbott@...hat.com>
To:     Brian Starkey <brian.starkey@....com>
Cc:     Sumit Semwal <sumit.semwal@...aro.org>,
        John Stultz <john.stultz@...aro.org>,
        Arve Hjønnevåg <arve@...roid.com>,
        Riley Andrews <riandrews@...roid.com>,
        Daniel Vetter <daniel.vetter@...ll.ch>,
        linaro-mm-sig@...ts.linaro.org, devel@...verdev.osuosl.org,
        linux-kernel@...r.kernel.org,
        Eun Taik Lee <eun.taik.lee@...sung.com>,
        Liviu Dudau <Liviu.Dudau@....com>,
        Jon Medhurst <tixy@...aro.org>,
        Mitchel Humpherys <mitchelh@...eaurora.org>,
        Jeremy Gebben <jgebben@...eaurora.org>,
        Bryan Huntsman <bryanh@...eaurora.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Android Kernel Team <kernel-team@...roid.com>,
        Chen Feng <puck.chen@...ilicon.com>
Subject: Re: [PATCHv2 1/4] staging: android: ion: Drop heap type masks

On 09/02/2016 06:41 AM, Brian Starkey wrote:
> Hi Laura,
>
> On Thu, Sep 01, 2016 at 03:40:41PM -0700, Laura Abbott wrote:
>>
>> There is no advantage to having heap types be a mask. The ion client has
>> long since dropped the mask. Drop the notion of heap type masks as well.
>>
>
> I know this is the same patch you sent last time, so sorry for not
> picking this up then - but I'm curious what "The" ion client is here?
>

ion_client_create used to take a mask to indicate what heap types it
could allocate from. This hasn't been the case since 2bb9f5034ec7
("gpu: ion: Remove heapmask from client"). "The ion client" probably
should have been "struct ion_client"

> Our ion client(s) certainly still use these masks, and it's still
> used as a mask within ion itself - even if the relationship between a
> mask and a heap type has been somewhat lost.

Where is it used in Ion? I don't see it in tree unless I missed something
and I'm not eager to keep this around for out of tree code. What's the
actual use for this?

>
> Thanks,
> Brian
>
>> Signed-off-by: Laura Abbott <labbott@...hat.com>
>> ---
>> drivers/staging/android/uapi/ion.h | 6 ------
>> 1 file changed, 6 deletions(-)
>>
>> diff --git a/drivers/staging/android/uapi/ion.h b/drivers/staging/android/uapi/ion.h
>> index 0a8e40f..a9c4e8b 100644
>> --- a/drivers/staging/android/uapi/ion.h
>> +++ b/drivers/staging/android/uapi/ion.h
>> @@ -44,14 +44,8 @@ enum ion_heap_type {
>>                    * must be last so device specific heaps always
>>                    * are at the end of this enum
>>                    */
>> -    ION_NUM_HEAPS = 16,
>> };
>>
>> -#define ION_HEAP_SYSTEM_MASK        (1 << ION_HEAP_TYPE_SYSTEM)
>> -#define ION_HEAP_SYSTEM_CONTIG_MASK    (1 << ION_HEAP_TYPE_SYSTEM_CONTIG)
>> -#define ION_HEAP_CARVEOUT_MASK        (1 << ION_HEAP_TYPE_CARVEOUT)
>> -#define ION_HEAP_TYPE_DMA_MASK        (1 << ION_HEAP_TYPE_DMA)
>> -
>> #define ION_NUM_HEAP_IDS        (sizeof(unsigned int) * 8)
>>
>> /**
>> --
>> 2.7.4
>>