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From: takahiro.akashi@linaro.org (AKASHI Takahiro)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v26 0/7] arm64: add kdump support
Date: Wed, 21 Sep 2016 16:42:50 +0900	[thread overview]
Message-ID: <20160921074249.GI30248@linaro.org> (raw)
In-Reply-To: <57E00CDC.70403@arm.com>

On Mon, Sep 19, 2016 at 05:05:48PM +0100, James Morse wrote:
> On 16/09/16 21:17, Ard Biesheuvel wrote:
> > On 16 September 2016 at 17:04, James Morse <james.morse@arm.com> wrote:
> >> Mark, Ard, how does/will reserved-memory work on an APCI only system?
> > 
> > It works by accident, at the moment. We used to ignore both
> > /memreserve/s and the /reserved-memory node, but due to some unrelated
> > refactoring, we ended up honouring the reserved-memory node when
> > booting via UEFI
> 
> Okay, so kdump probably shouldn't rely on this behaviour...
> 
> For an acpi-only system, we could get reserve_crashkernel() to copy the uefi
> memory map into the reserved region, changing the region types for existing
> kernel memory to EfiReservedMemoryType (for example) and fixing up the reserved
> region boundaries.
> 
> This second memory map could then be added alongside the real one in the
> DT/chosen, and used in preference the second time we go through uefi_init() in
> the crash kernel.

Do we need add this map as the second one?
Why not replace "linux,uefi-mmap-start" in a new blob?

> kexec-tools would still need to keep the '/reserved-memory' node for non-uefi
> systems.

Yeah, but if we go in our own way on UEFI/ACPI systems, we may want to
go in a DT-specific way, like PPC does, on DT systems.
(That is, "linux,usable-memory" in memory nodes.)

Thanks,
-Takahiro AKASHI

> Doing this doesn't depend on userspace, and means the uefi memory map is still
> the one and only true source of memory layout information. If fixing it like
> this is valid I don't think it should block kdump.
> 
> ... I will think about this some more before trying to put it together.
> 
> 
> 
> Thanks,
> 
> James

WARNING: multiple messages have this Message-ID (diff)
From: AKASHI Takahiro <takahiro.akashi@linaro.org>
To: James Morse <james.morse@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Geoff Levand <geoff@infradead.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>,
	Dave Young <dyoung@redhat.com>,
	"kexec@lists.infradead.org" <kexec@lists.infradead.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v26 0/7] arm64: add kdump support
Date: Wed, 21 Sep 2016 16:42:50 +0900	[thread overview]
Message-ID: <20160921074249.GI30248@linaro.org> (raw)
In-Reply-To: <57E00CDC.70403@arm.com>

On Mon, Sep 19, 2016 at 05:05:48PM +0100, James Morse wrote:
> On 16/09/16 21:17, Ard Biesheuvel wrote:
> > On 16 September 2016 at 17:04, James Morse <james.morse@arm.com> wrote:
> >> Mark, Ard, how does/will reserved-memory work on an APCI only system?
> > 
> > It works by accident, at the moment. We used to ignore both
> > /memreserve/s and the /reserved-memory node, but due to some unrelated
> > refactoring, we ended up honouring the reserved-memory node when
> > booting via UEFI
> 
> Okay, so kdump probably shouldn't rely on this behaviour...
> 
> For an acpi-only system, we could get reserve_crashkernel() to copy the uefi
> memory map into the reserved region, changing the region types for existing
> kernel memory to EfiReservedMemoryType (for example) and fixing up the reserved
> region boundaries.
> 
> This second memory map could then be added alongside the real one in the
> DT/chosen, and used in preference the second time we go through uefi_init() in
> the crash kernel.

Do we need add this map as the second one?
Why not replace "linux,uefi-mmap-start" in a new blob?

> kexec-tools would still need to keep the '/reserved-memory' node for non-uefi
> systems.

Yeah, but if we go in our own way on UEFI/ACPI systems, we may want to
go in a DT-specific way, like PPC does, on DT systems.
(That is, "linux,usable-memory" in memory nodes.)

Thanks,
-Takahiro AKASHI

> Doing this doesn't depend on userspace, and means the uefi memory map is still
> the one and only true source of memory layout information. If fixing it like
> this is valid I don't think it should block kdump.
> 
> ... I will think about this some more before trying to put it together.
> 
> 
> 
> Thanks,
> 
> James

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kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

  parent reply	other threads:[~2016-09-21  7:42 UTC|newest]

Thread overview: 90+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-07  4:29 [PATCH v26 0/7] arm64: add kdump support AKASHI Takahiro
2016-09-07  4:29 ` AKASHI Takahiro
2016-09-07  4:29 ` [PATCH v26 1/7] arm64: kdump: reserve memory for crash dump kernel AKASHI Takahiro
2016-09-07  4:29   ` AKASHI Takahiro
2016-09-22 10:23   ` Matthias Bruger
2016-09-22 10:23     ` Matthias Bruger
2016-09-23  8:37     ` AKASHI Takahiro
2016-09-23  8:37       ` AKASHI Takahiro
2016-09-07  4:29 ` [PATCH v26 2/7] arm64: kdump: implement machine_crash_shutdown() AKASHI Takahiro
2016-09-07  4:29   ` AKASHI Takahiro
2016-09-14 18:09   ` James Morse
2016-09-14 18:09     ` James Morse
2016-09-15  8:13     ` Marc Zyngier
2016-09-15  8:13       ` Marc Zyngier
2016-09-16  3:21     ` AKASHI Takahiro
2016-09-16  3:21       ` AKASHI Takahiro
2016-09-16 14:49       ` James Morse
2016-09-16 14:49         ` James Morse
2016-09-20  7:36         ` AKASHI Takahiro
2016-09-20  7:36           ` AKASHI Takahiro
2016-09-07  4:29 ` [PATCH v26 3/7] arm64: kdump: add kdump support AKASHI Takahiro
2016-09-07  4:29   ` AKASHI Takahiro
2016-09-16 14:50   ` James Morse
2016-09-16 14:50     ` James Morse
2016-09-20  7:46     ` AKASHI Takahiro
2016-09-20  7:46       ` AKASHI Takahiro
2016-09-22 15:50   ` Matthias Brugger
2016-09-22 15:50     ` Matthias Brugger
2016-09-07  4:29 ` [PATCH v26 4/7] arm64: kdump: add VMCOREINFO's for user-space coredump tools AKASHI Takahiro
2016-09-07  4:29   ` AKASHI Takahiro
2016-09-16 16:04   ` James Morse
2016-09-16 16:04     ` James Morse
2016-09-07  4:29 ` [PATCH v26 5/7] arm64: kdump: enable kdump in the arm64 defconfig AKASHI Takahiro
2016-09-07  4:29   ` AKASHI Takahiro
2016-09-07  4:29 ` [PATCH v26 6/7] arm64: kdump: update a kernel doc AKASHI Takahiro
2016-09-07  4:29   ` AKASHI Takahiro
2016-09-16 16:08   ` James Morse
2016-09-16 16:08     ` James Morse
2016-09-20  8:27     ` AKASHI Takahiro
2016-09-20  8:27       ` AKASHI Takahiro
2016-09-26 17:21     ` Matthias Brugger
2016-09-26 17:21       ` Matthias Brugger
     [not found] ` <20160907042908.6232-1-takahiro.akashi-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2016-09-07  4:32   ` [PATCH v26 7/7] Documentation: dt: chosen properties for arm64 kdump AKASHI Takahiro
2016-09-07  4:32     ` AKASHI Takahiro
2016-09-07  4:32     ` AKASHI Takahiro
     [not found]     ` <20160907043203.6309-1-takahiro.akashi-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2016-09-16 13:03       ` Rob Herring
2016-09-16 13:03         ` Rob Herring
2016-09-16 13:03         ` Rob Herring
2016-09-07  4:37 ` [PATCH v26 0/7] arm64: add kdump support AKASHI Takahiro
2016-09-07  4:37   ` AKASHI Takahiro
2016-09-16 16:04 ` James Morse
2016-09-16 16:04   ` James Morse
2016-09-16 20:17   ` Ard Biesheuvel
2016-09-16 20:17     ` Ard Biesheuvel
2016-09-19 16:05     ` James Morse
2016-09-19 16:05       ` James Morse
2016-09-19 16:10       ` Ard Biesheuvel
2016-09-19 16:10         ` Ard Biesheuvel
2016-09-21  7:42       ` AKASHI Takahiro [this message]
2016-09-21  7:42         ` AKASHI Takahiro
2016-09-21  7:33   ` AKASHI Takahiro
2016-09-21  7:33     ` AKASHI Takahiro
2016-10-03  7:54 ` Manish Jaggi
2016-10-03  7:54   ` Manish Jaggi
2016-10-03 11:04   ` AKASHI Takahiro
2016-10-03 11:04     ` AKASHI Takahiro
2016-10-03 12:41     ` Manish Jaggi
2016-10-03 12:41       ` Manish Jaggi
2016-10-04  2:56       ` AKASHI Takahiro
2016-10-04  2:56         ` AKASHI Takahiro
2016-10-04  9:46       ` James Morse
2016-10-04  9:46         ` James Morse
2016-10-04 10:05         ` Manish Jaggi
2016-10-04 10:05           ` Manish Jaggi
2016-10-04 10:53           ` James Morse
2016-10-04 10:53             ` James Morse
2016-10-04 13:23             ` Manish Jaggi
2016-10-04 13:23               ` Manish Jaggi
2016-10-05  5:48               ` AKASHI Takahiro
2016-10-05  5:48                 ` AKASHI Takahiro
2016-10-05  5:41         ` AKASHI Takahiro
2016-10-05  5:41           ` AKASHI Takahiro
2016-10-04 10:18       ` Mark Rutland
2016-10-04 10:18         ` Mark Rutland
2016-10-17 15:41 ` Ruslan Bilovol
2016-10-17 15:41   ` Ruslan Bilovol
2016-10-18  6:26   ` AKASHI Takahiro
2016-10-18  6:26     ` AKASHI Takahiro
2016-11-01 12:19     ` Ruslan Bilovol
2016-11-01 12:19       ` Ruslan Bilovol

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