From: AKASHI Takahiro <takahiro.akashi@linaro.org>
To: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: geoff@infradead.org, catalin.marinas@arm.com,
kexec@lists.infradead.org, will.deacon@arm.com,
james.morse@arm.com, linuxppc-dev@lists.ozlabs.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v21 8/8] Documentation: dt: usable-memory and elfcorehdr nodes for arm64 kexec
Date: Thu, 7 Jul 2016 11:00:25 +0900 [thread overview]
Message-ID: <20160707020025.GY20774@linaro.org> (raw)
In-Reply-To: <6483018.WWW2TSJB10@hactar>
On Wed, Jul 06, 2016 at 04:29:18PM -0300, Thiago Jung Bauermann wrote:
> Hi,
>
> Am Mittwoch, 06 Juli 2016, 16:52:26 schrieb AKASHI Takahiro:
> > +linux,usable-memory
> > +-------------------
> > +
> > +This property is set on PowerPC and arm64 by kexec-tools during kdump
> > +to tell the crash kernel the base address of its reserved area of memory,
> > and +the size. e.g.
> > +
> > +/ {
> > + chosen {
> > + linux,usable-memory = <0x9 0xf0000000 0x0 0x10000000>;
> > + };
> > +};
>
> Again, this description is wrong for PowerPC. See messages from myself and
> Michael Ellerman:
>
> https://lists.infradead.org/pipermail/kexec/2016-June/016250.html
>
> https://lists.infradead.org/pipermail/kexec/2016-June/016253.html
Oops, I must have missed your previous comments. Apologies.
Yes, I know that, and I used to implement the same functionality before.
It did work for dtb-based systems, but not for UEFI(ACPI)-based systems
because UEFI doesn't export memory regions information via a device tree,
but rather via ACPI table. So "/memory" node won't appear.
So I went back with "mem=" command line approach, and later this "/chosen/"
approach.
> IMHO, it would be simpler if ARM used linux,usable-memory in the same way
> that PowerPC does, for consistency.
Well, this property won't conflict with per-"/memory" ones
if we take it that the former, if present, supersedes the latter.
Sophistic?
What about changing the name to usable-memory-limit?
(I know that you have another one, "memory-limit" though.)
Again, I would like to defer to arm64 maintainers.
Thanks,
-Takahiro AKASHI
> --
> []'s
> Thiago Jung Bauermann
> IBM Linux Technology Center
>
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WARNING: multiple messages have this Message-ID (diff)
From: AKASHI Takahiro <takahiro.akashi@linaro.org>
To: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: kexec@lists.infradead.org, catalin.marinas@arm.com,
will.deacon@arm.com, geoff@infradead.org, james.morse@arm.com,
linux-arm-kernel@lists.infradead.org,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v21 8/8] Documentation: dt: usable-memory and elfcorehdr nodes for arm64 kexec
Date: Thu, 7 Jul 2016 11:00:25 +0900 [thread overview]
Message-ID: <20160707020025.GY20774@linaro.org> (raw)
In-Reply-To: <6483018.WWW2TSJB10@hactar>
On Wed, Jul 06, 2016 at 04:29:18PM -0300, Thiago Jung Bauermann wrote:
> Hi,
>
> Am Mittwoch, 06 Juli 2016, 16:52:26 schrieb AKASHI Takahiro:
> > +linux,usable-memory
> > +-------------------
> > +
> > +This property is set on PowerPC and arm64 by kexec-tools during kdump
> > +to tell the crash kernel the base address of its reserved area of memory,
> > and +the size. e.g.
> > +
> > +/ {
> > + chosen {
> > + linux,usable-memory = <0x9 0xf0000000 0x0 0x10000000>;
> > + };
> > +};
>
> Again, this description is wrong for PowerPC. See messages from myself and
> Michael Ellerman:
>
> https://lists.infradead.org/pipermail/kexec/2016-June/016250.html
>
> https://lists.infradead.org/pipermail/kexec/2016-June/016253.html
Oops, I must have missed your previous comments. Apologies.
Yes, I know that, and I used to implement the same functionality before.
It did work for dtb-based systems, but not for UEFI(ACPI)-based systems
because UEFI doesn't export memory regions information via a device tree,
but rather via ACPI table. So "/memory" node won't appear.
So I went back with "mem=" command line approach, and later this "/chosen/"
approach.
> IMHO, it would be simpler if ARM used linux,usable-memory in the same way
> that PowerPC does, for consistency.
Well, this property won't conflict with per-"/memory" ones
if we take it that the former, if present, supersedes the latter.
Sophistic?
What about changing the name to usable-memory-limit?
(I know that you have another one, "memory-limit" though.)
Again, I would like to defer to arm64 maintainers.
Thanks,
-Takahiro AKASHI
> --
> []'s
> Thiago Jung Bauermann
> IBM Linux Technology Center
>
WARNING: multiple messages have this Message-ID (diff)
From: takahiro.akashi@linaro.org (AKASHI Takahiro)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v21 8/8] Documentation: dt: usable-memory and elfcorehdr nodes for arm64 kexec
Date: Thu, 7 Jul 2016 11:00:25 +0900 [thread overview]
Message-ID: <20160707020025.GY20774@linaro.org> (raw)
In-Reply-To: <6483018.WWW2TSJB10@hactar>
On Wed, Jul 06, 2016 at 04:29:18PM -0300, Thiago Jung Bauermann wrote:
> Hi,
>
> Am Mittwoch, 06 Juli 2016, 16:52:26 schrieb AKASHI Takahiro:
> > +linux,usable-memory
> > +-------------------
> > +
> > +This property is set on PowerPC and arm64 by kexec-tools during kdump
> > +to tell the crash kernel the base address of its reserved area of memory,
> > and +the size. e.g.
> > +
> > +/ {
> > + chosen {
> > + linux,usable-memory = <0x9 0xf0000000 0x0 0x10000000>;
> > + };
> > +};
>
> Again, this description is wrong for PowerPC. See messages from myself and
> Michael Ellerman:
>
> https://lists.infradead.org/pipermail/kexec/2016-June/016250.html
>
> https://lists.infradead.org/pipermail/kexec/2016-June/016253.html
Oops, I must have missed your previous comments. Apologies.
Yes, I know that, and I used to implement the same functionality before.
It did work for dtb-based systems, but not for UEFI(ACPI)-based systems
because UEFI doesn't export memory regions information via a device tree,
but rather via ACPI table. So "/memory" node won't appear.
So I went back with "mem=" command line approach, and later this "/chosen/"
approach.
> IMHO, it would be simpler if ARM used linux,usable-memory in the same way
> that PowerPC does, for consistency.
Well, this property won't conflict with per-"/memory" ones
if we take it that the former, if present, supersedes the latter.
Sophistic?
What about changing the name to usable-memory-limit?
(I know that you have another one, "memory-limit" though.)
Again, I would like to defer to arm64 maintainers.
Thanks,
-Takahiro AKASHI
> --
> []'s
> Thiago Jung Bauermann
> IBM Linux Technology Center
>
next prev parent reply other threads:[~2016-07-07 1:55 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-06 7:52 [PATCH v21 0/8] arm64: kdump support AKASHI Takahiro
2016-07-06 7:52 ` AKASHI Takahiro
2016-07-06 7:52 ` [PATCH v21 1/8] arm64: kdump: reserve memory for crash dump kernel AKASHI Takahiro
2016-07-06 7:52 ` AKASHI Takahiro
2016-07-06 17:00 ` Geoff Levand
2016-07-06 17:00 ` Geoff Levand
2016-07-07 0:19 ` AKASHI Takahiro
2016-07-07 0:19 ` AKASHI Takahiro
2016-07-06 18:11 ` Thiago Jung Bauermann
2016-07-06 18:11 ` Thiago Jung Bauermann
2016-07-07 1:17 ` AKASHI Takahiro
2016-07-07 1:17 ` AKASHI Takahiro
2016-07-06 7:52 ` [PATCH v21 2/8] arm64: limit memory regions based on DT property, usable-memory AKASHI Takahiro
2016-07-06 7:52 ` AKASHI Takahiro
2016-07-06 17:48 ` Geoff Levand
2016-07-06 17:48 ` Geoff Levand
2016-07-06 7:52 ` [PATCH v21 3/8] arm64: kdump: implement machine_crash_shutdown() AKASHI Takahiro
2016-07-06 7:52 ` AKASHI Takahiro
2016-07-06 17:28 ` Geoff Levand
2016-07-06 17:28 ` Geoff Levand
2016-07-07 0:43 ` AKASHI Takahiro
2016-07-07 0:43 ` AKASHI Takahiro
2016-07-07 16:42 ` Geoff Levand
2016-07-07 16:42 ` Geoff Levand
2016-07-06 7:52 ` [PATCH v21 4/8] arm64: kdump: add kdump support AKASHI Takahiro
2016-07-06 7:52 ` AKASHI Takahiro
2016-07-06 17:38 ` Geoff Levand
2016-07-06 17:38 ` Geoff Levand
2016-07-07 0:49 ` AKASHI Takahiro
2016-07-07 0:49 ` AKASHI Takahiro
2016-07-06 7:52 ` [PATCH v21 5/8] arm64: kdump: add VMCOREINFO's for user-space coredump tools AKASHI Takahiro
2016-07-06 7:52 ` AKASHI Takahiro
2016-07-06 7:52 ` [PATCH v21 6/8] arm64: kdump: enable kdump in the arm64 defconfig AKASHI Takahiro
2016-07-06 7:52 ` AKASHI Takahiro
2016-07-06 7:52 ` [PATCH v21 7/8] arm64: kdump: update a kernel doc AKASHI Takahiro
2016-07-06 7:52 ` AKASHI Takahiro
2016-07-06 17:44 ` Geoff Levand
2016-07-06 17:44 ` Geoff Levand
2016-07-07 0:51 ` AKASHI Takahiro
2016-07-07 0:51 ` AKASHI Takahiro
2016-07-06 7:52 ` [PATCH v21 8/8] Documentation: dt: usable-memory and elfcorehdr nodes for arm64 kexec AKASHI Takahiro
2016-07-06 7:52 ` AKASHI Takahiro
2016-07-06 17:46 ` Geoff Levand
2016-07-06 17:46 ` Geoff Levand
2016-07-06 19:29 ` Thiago Jung Bauermann
2016-07-06 19:29 ` Thiago Jung Bauermann
2016-07-06 19:29 ` Thiago Jung Bauermann
2016-07-07 2:00 ` AKASHI Takahiro [this message]
2016-07-07 2:00 ` AKASHI Takahiro
2016-07-07 2:00 ` AKASHI Takahiro
2016-07-07 18:46 ` Thiago Jung Bauermann
2016-07-07 18:46 ` Thiago Jung Bauermann
2016-07-07 18:46 ` Thiago Jung Bauermann
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