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Date: Wed, 22 May 2024 08:20:39 +0000
From: Wei Yang <richard.weiyang@gmail.com>
To: Jaewon Kim <jaewon31.kim@samsung.com>
Cc: "rppt@kernel.org" <rppt@kernel.org>, "vbabka@suse.cz" <vbabka@suse.cz>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
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	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"jaewon31.kim@gmail.com" <jaewon31.kim@gmail.com>,
	"tkjos@google.com" <tkjos@google.com>
Subject: Re: [RESEND PATCH 00/10] memblock: introduce memsize showing
 reserved memory
Message-ID: <20240522082039.j4zgfj3lhjdwgrtc@master>
Reply-To: Wei Yang <richard.weiyang@gmail.com>
References: <20240521023957.2587005-1-jaewon31.kim@samsung.com>
 <CGME20240521024009epcas1p10ed9f9b929203183a29f79508e79bb76@epcms1p6>
 <20240521025329epcms1p6ce11064c0f0608a0156d82fda7ef285c@epcms1p6>
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On Tue, May 21, 2024 at 11:53:29AM +0900, Jaewon Kim wrote:
>>--------- Original Message ---------
>>Sender : 김재원 <jaewon31.kim@samsung.com>System Performance Lab.(MX)/삼성전자
>>Date   : 2024-05-21 11:40 (GMT+9)
>>Title  : [RESEND PATCH 00/10] memblock: introduce memsize showing reserved memory
>>?
>>Some of memory regions can be reserved for a specific purpose. They are
>>usually defined through reserved-memory in device tree. If only size
>>without address is specified in device tree, the address of the region
>>will be determined at boot time.
>>
>>We may find the address of the memory regions through booting log, but
>>it does not show all. And it could be hard to catch the very beginning
>>log. The memblock_dump_all shows all memblock status but it does not
>>show region name and its information is difficult to summarize.
>>
>>This patch introduce a debugfs node, memblock/memsize, to see reserved
>>memory easily.
>>
>>Here's an example
>>
>>$ cat debugfs/memblock/memsize
>>
>>0x0000000000000000-0x0000000000000000 0x02000000 (?  32768 KB )?  map reusable linux,cma
>>0x0000000000000000-0x0000000000000000 0x01000000 (?  16384 KB )?  map reusable vxxxxx
>>...
>>0x0000000000000000-0x0000000000000000 0x004e0000 (? ? 4992 KB ) nomap unusable unknown
>>0x0000000000000000-0x0000000000000000 0x00400000 (? ? 4096 KB ) nomap unusable cxxxxx
>>0x0000000000000000-0x0000000000000000 0x00e00000 (?  14336 KB ) nomap unusable gxxxxx
>>
>>Reserved? ? : 1223856 KB
>> .kernel? ? :? 275208 KB
>>? .text? ?  :?  16576 KB
>>? .rwdata?  :? ? 1963 KB
>>? .rodata?  :?  11920 KB
>>? .bss? ? ? :? ? 2450 KB
>>? .memmap?  :? 186368 KB
>>? .etc? ? ? :?  55933 KB
>> .unusable? :? 948648 KB
>>System? ? ? : 11359056 KB
>> .common? ? : 10306384 KB
>> .reusable? : 1052672 KB
>>Total? ? ?  : 12582912 KB ( 12288.00 MB )
>>
>>Jaewon Kim (10):
>>? memblock: introduce memsize showing reserved memory
>>? memblock: detect hidden memory hole size
>>? memblock: handle overlapped reserved memory region
>>? memblock: take a region intersecting an unknown region
>>? memblock: track memblock changed at early param
>>? memblock: recognize late freed size by checking PageReserved
>>? memblock: track kernel size on memsize
>>? memblock: print memsize summary information
>>? memblock: print kernel internal size
>>? memblock: support memsize reusable to consider as reusable
>>
>> drivers/of/fdt.c? ? ? ? ? ?  |? 11 +
>> drivers/of/of_reserved_mem.c |? 12 +-
>> include/linux/memblock.h? ?  |? 29 ++
>> init/main.c? ? ? ? ? ? ? ? ? |? 13 +-
>> kernel/dma/contiguous.c? ? ? |?  9 +-
>> mm/Kconfig? ? ? ? ? ? ? ? ?  |? 16 ++
>> mm/memblock.c? ? ? ? ? ? ? ? | 502 ++++++++++++++++++++++++++++++++++-
>> mm/mm_init.c? ? ? ? ? ? ? ?  |?  6 +-
>> mm/page_allocc? ? ? ? ? ? ? |? 10 +-
>> 9 files changed, 597 insertions(+), 11 deletions(-)
>>
>>-- 
>>2.25.1
>
>Hello Mike 
>
>This is actually RESEND as it was introduced 2 years ago.
>Please refer to https://lore.kernel.org/linux-mm/YkQB6Ah603yPR3qf@kernel.org/#t
>
>> But you never provided details about *why* you want this information exposed.
>
>For your question, I'd like to say ;
>We can see the same format and exact information between different version of kernel status.
>
>1) Internally we can check if the reserved memory changes.
>2) Externally we can communicate between chipset vendors and OEM, with a same format.
>

Maybe you can show the log difference, so that we can see how it helps you.

>This helps us to communitcate well, to easily detect changes or just to see differences.
>
>Jaewon Kim
>

-- 
Wei Yang
Help you, Help me