Re: [PATCH v2] board: kontron: increase the CONFIG_SYS_MALLOC_F_LEN

[Sean Anderson <seanga2@gmail.com>]

On 3/23/22 2:26 PM, Heiko Thiery wrote:
> Hi Simon,
> 
> Am Mi., 23. März 2022 um 19:04 Uhr schrieb Simon Glass <sjg@chromium.org>:
>>
>> Hi Heinrich,
>>
>> On Tue, 22 Mar 2022 at 03:25, Heinrich Schuchardt <xypron.glpk@gmx.de> wrote:
>>>
>>> On 3/21/22 15:26, Heiko Thiery wrote:
>>>> It was observed that enabling additional DM modules the configured
>>>> malloc value is not sufficient. So lets increase the value.
>>>>
>>>> Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com>
>>>> ---
>>>> v2:
>>>>    - add a more proper commit message to explan why the value was increased
>>>>
>>>>    configs/kontron_pitx_imx8m_defconfig | 1 +
>>>>    1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/configs/kontron_pitx_imx8m_defconfig b/configs/kontron_pitx_imx8m_defconfig
>>>> index 76430213e3..30c3586937 100644
>>>> --- a/configs/kontron_pitx_imx8m_defconfig
>>>> +++ b/configs/kontron_pitx_imx8m_defconfig
>>>> @@ -2,6 +2,7 @@ CONFIG_ARM=y
>>>>    CONFIG_ARCH_IMX8M=y
>>>>    CONFIG_SYS_TEXT_BASE=0x40200000
>>>>    CONFIG_SYS_MALLOC_LEN=0x600000
>>>> +CONFIG_SYS_MALLOC_F_LEN=0x10000
>>>
>>> @Heiko
>>> Should we really adjust this on board level? Won't we have the same
>>> problem on all imx8m boards?
>>>
>>> Why don't you change the default for all i.mx8 boards in /Kconfig?
>>>
>>> @Tom, @Simon
>>> Shouldn't we replace the default of 0x400 by 0x2000 generally?
>>
>> I don't think that is a good idea. That is a lot of memory! Many
>> platforms don't need that much.
>>
>> I wonder what is driving this large amount. Is it pinctrl?
> 
> The increase comes from the introduction of a clock driver for the
> imx8mq platform.

Yes, the problem is that CCF creates a udevice+clk+private data for
every clock. This runs about 150-200 bytes per clock on a 64-bit
platform. In addition, many physical clocks are modeled as several
logical clocks plus a composite. This means a platform with maybe
20-30 physical clocks can easily allocate 10k-20k to create
the clock tree.

--Sean