From: Jaewon Kim <jaewon31.kim@samsung.com>
To: Mike Rapoport <rppt@kernel.org>
Cc: "vbabka@suse.cz" <vbabka@suse.cz>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
YongTaek Lee <ytk.lee@samsung.com>,
"jaewon31.kim@gmail.com" <jaewon31.kim@gmail.com>
Subject: RE: [PATCH 0/8] memblock: introduce memsize showing reserved memory
Date: Wed, 30 Mar 2022 16:22:30 +0900 [thread overview]
Message-ID: <20220330072230epcms1p87c4b557f88fe166f339dfa72eb96ec8c@epcms1p8> (raw)
In-Reply-To: <YkQB6Ah603yPR3qf@kernel.org>
>Hi,
>
>On Tue, Mar 29, 2022 at 11:46:20AM +0900, Jaewon Kim wrote:
>> >> >
>> >> >I'm still not following. The reserved region sizes are available in the
>> >> >existing memblock debugfs.
>> >> >Why the names are important? What is the value of having names for *some*
>> >> >of the reserved regions?
>> >>
>> >> Hi
>> >>
>> >> There are many memory regions in memblock debugfs memory/reserved, and some might
>> >> be splited or merged with other region. Among regions in debugfs, we can't find
>> >> the one we defined in device tree. Especially it is difficult to find the region we
>> >> described size only without start address.
>> >>
>> >> On mobile environment, memory is used by not only CPU but also GPU, Camera, Secure
>> >> world, Audio, ETC. To support them, there are many reserved regions described in
>> >> device tree. So the name is quite important to recognize a region. And with thename
>> >> we can compare reserved memory map with other map.
>> >
>> >You still didn't describe your use case. What is the problem your patches
>> >are trying to solve? Why is it important to know what is the use of particular
>> >reserved region?
>> >
>> >You propose complex mechanism that seems to fit very particular scenario
>> >and sprinkle some calls to this mechanism at random places because you need
>> >to "compare reserved memory map with other map".
>> >
>> >Does not sound convincing to me, sorry.
>>
>> As I said serveral times, I want a simple knob showing all reserved
>> memory status. The current debugfs, device tree do not show all those
>> information I want. I think you also know that. i.e. late freed pages,
>> splited or merged memblock, address defined at boot time, kernel size,
>> ETC.
>
>I know that there is not much information about reserved memory exposed and
>I understand *what* are you trying to achieve. But you never provided
>details about *why* you want this information exposed.
>
>I don't mind providing more visibility into reserved memory attributes in
>general, but I'd like to see something way more simple and localized.
>
I think the "what" is same as "why".
I want to look at all reservced memory status simply in a knob.
I also want to make in more simple and localized way, but there seems be
several ways to change reserved memory such as cmdline way, freeing after
boot, etc. I wanted to cover all those things.
That's OK. I hope someone later to try this again to show all the info.
>--
>Sincerely yours,
>Mike.
prev parent reply other threads:[~2022-03-30 7:23 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20220324065919epcas1p4c79da5f6ec4fa0311409ca24a38785d8@epcas1p4.samsung.com>
2022-03-24 7:01 ` [PATCH 0/8] memblock: introduce memsize showing reserved memory Jaewon Kim
[not found] ` <CGME20220324065919epcas1p35bafcd9151cf0469e4e933250c491a88@epcas1p3.samsung.com>
2022-03-24 7:01 ` [PATCH 1/8] " Jaewon Kim
[not found] ` <CGME20220324065919epcas1p1b30eabc8bbe01da1ef90280b6ee8bcea@epcas1p1.samsung.com>
2022-03-24 7:01 ` [PATCH 2/8] memblock: detect hidden memory hole size Jaewon Kim
[not found] ` <CGME20220324065919epcas1p3429ec2c9595c54ffe4ee25f273febd1c@epcas1p3.samsung.com>
2022-03-24 7:01 ` [PATCH 3/8] memblock: handle overlapped reserved memory region Jaewon Kim
[not found] ` <CGME20220324065919epcas1p256ff799f37a765a432475808e708d639@epcas1p2.samsung.com>
2022-03-24 7:01 ` [PATCH 4/8] memblock: track memblock changed at early param Jaewon Kim
[not found] ` <CGME20220324065919epcas1p3a3a267c4348be4fd3bb8437d4e6db142@epcas1p3.samsung.com>
2022-03-24 7:01 ` [PATCH 5/8] memblock: track kernel size on memsize Jaewon Kim
[not found] ` <CGME20220324065919epcas1p1058e2841b009d8c7d683bc0408f8a5a4@epcas1p1.samsung.com>
2022-03-24 7:01 ` [PATCH 6/8] memblock: recognize late free by checking PageReserved Jaewon Kim
[not found] ` <CGME20220324065919epcas1p4b935c884aa3fde0917f6dff8bff128ed@epcas1p4.samsung.com>
2022-03-24 7:01 ` [PATCH 7/8] memblock: print memsize summary information Jaewon Kim
[not found] ` <CGME20220324065919epcas1p46b5381b1b839d7076673c23e8f9b0bba@epcas1p4.samsung.com>
2022-03-24 7:01 ` [PATCH 8/8] memblock: print kernel internal size Jaewon Kim
2022-03-25 7:46 ` [PATCH 0/8] memblock: introduce memsize showing reserved memory Mike Rapoport
[not found] ` <CGME20220324065919epcas1p4c79da5f6ec4fa0311409ca24a38785d8@epcms1p3>
2022-03-25 8:38 ` Jaewon Kim
2022-03-27 7:40 ` Mike Rapoport
[not found] ` <CGME20220324065919epcas1p4c79da5f6ec4fa0311409ca24a38785d8@epcms1p1>
2022-03-27 13:53 ` Jaewon Kim
2022-03-27 15:15 ` Mike Rapoport
[not found] ` <CGME20220324065919epcas1p4c79da5f6ec4fa0311409ca24a38785d8@epcms1p7>
2022-03-29 2:46 ` Jaewon Kim
2022-03-30 7:08 ` Mike Rapoport
[not found] ` <CGME20220324065919epcas1p4c79da5f6ec4fa0311409ca24a38785d8@epcms1p8>
2022-03-30 7:22 ` Jaewon Kim [this message]
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