Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-14 Thread Prarit Bhargava
On 01/13/2014 07:33 PM, Toshi Kani wrote: > On Mon, 2014-01-13 at 18:39 -0500, Prarit Bhargava wrote: >> >> On 01/13/2014 03:31 PM, KOSAKI Motohiro wrote: >>> On Sun, Jan 12, 2014 at 6:46 PM, Prarit Bhargava wrote: On 01/11/2014 11:35 AM, 7egg...@gmx.de wrote: > > >

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-14 Thread Prarit Bhargava
On 01/13/2014 07:33 PM, Toshi Kani wrote: On Mon, 2014-01-13 at 18:39 -0500, Prarit Bhargava wrote: On 01/13/2014 03:31 PM, KOSAKI Motohiro wrote: On Sun, Jan 12, 2014 at 6:46 PM, Prarit Bhargava pra...@redhat.com wrote: On 01/11/2014 11:35 AM, 7egg...@gmx.de wrote: On Fri, 10 Jan

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread Toshi Kani
On Tue, 2014-01-14 at 09:52 +0800, Dave Young wrote: > On 01/13/14 at 06:09pm, Toshi Kani wrote: > > On Mon, 2014-01-13 at 16:53 -0800, H. Peter Anvin wrote: > > > On 01/13/2014 04:33 PM, Toshi Kani wrote: > > > > > > > > I do not think it makes sense. You needed memmap=exactmap as a > > > >

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread Dave Young
On 01/13/14 at 06:09pm, Toshi Kani wrote: > On Mon, 2014-01-13 at 16:53 -0800, H. Peter Anvin wrote: > > On 01/13/2014 04:33 PM, Toshi Kani wrote: > > > > > > I do not think it makes sense. You needed memmap=exactmap as a > > > workaround because the kernel did not boot with the firmware's

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread Toshi Kani
On Mon, 2014-01-13 at 17:29 -0800, H. Peter Anvin wrote: > On 01/13/2014 05:09 PM, Toshi Kani wrote: > > > > In majority of the cases, memmap=exactmap is used for kdump and the > > firmware info is sane. So, I think we should keep NUMA enabled since it > > could be useful when multiple CPUs are

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread H. Peter Anvin
On 01/13/2014 05:09 PM, Toshi Kani wrote: > > In majority of the cases, memmap=exactmap is used for kdump and the > firmware info is sane. So, I think we should keep NUMA enabled since it > could be useful when multiple CPUs are enabled for kdump. > Rather unlikely since all of the kdump

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread Toshi Kani
On Mon, 2014-01-13 at 16:53 -0800, H. Peter Anvin wrote: > On 01/13/2014 04:33 PM, Toshi Kani wrote: > > > > I do not think it makes sense. You needed memmap=exactmap as a > > workaround because the kernel did not boot with the firmware's memory > > info. So, it's broken, and you requested the

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread H. Peter Anvin
On 01/13/2014 04:33 PM, Toshi Kani wrote: > > I do not think it makes sense. You needed memmap=exactmap as a > workaround because the kernel did not boot with the firmware's memory > info. So, it's broken, and you requested the kernel to ignore the > firmware info. > > Why do you think memory

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread Toshi Kani
On Mon, 2014-01-13 at 18:39 -0500, Prarit Bhargava wrote: > > On 01/13/2014 03:31 PM, KOSAKI Motohiro wrote: > > On Sun, Jan 12, 2014 at 6:46 PM, Prarit Bhargava wrote: > >> > >> > >> On 01/11/2014 11:35 AM, 7egg...@gmx.de wrote: > >>> > >>> > >>> On Fri, 10 Jan 2014, Prarit Bhargava wrote: >

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread Prarit Bhargava
On 01/13/2014 03:31 PM, KOSAKI Motohiro wrote: > On Sun, Jan 12, 2014 at 6:46 PM, Prarit Bhargava wrote: >> >> >> On 01/11/2014 11:35 AM, 7egg...@gmx.de wrote: >>> >>> >>> On Fri, 10 Jan 2014, Prarit Bhargava wrote: >>> kdump uses memmap=exactmap and mem=X values to configure the memory

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread KOSAKI Motohiro
On Sun, Jan 12, 2014 at 6:46 PM, Prarit Bhargava wrote: > > > On 01/11/2014 11:35 AM, 7egg...@gmx.de wrote: >> >> >> On Fri, 10 Jan 2014, Prarit Bhargava wrote: >> >>> kdump uses memmap=exactmap and mem=X values to configure the memory >>> mapping for the kdump kernel. If memory is hotadded

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread KOSAKI Motohiro
On Sun, Jan 12, 2014 at 6:46 PM, Prarit Bhargava pra...@redhat.com wrote: On 01/11/2014 11:35 AM, 7egg...@gmx.de wrote: On Fri, 10 Jan 2014, Prarit Bhargava wrote: kdump uses memmap=exactmap and mem=X values to configure the memory mapping for the kdump kernel. If memory is hotadded

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread Prarit Bhargava
On 01/13/2014 03:31 PM, KOSAKI Motohiro wrote: On Sun, Jan 12, 2014 at 6:46 PM, Prarit Bhargava pra...@redhat.com wrote: On 01/11/2014 11:35 AM, 7egg...@gmx.de wrote: On Fri, 10 Jan 2014, Prarit Bhargava wrote: kdump uses memmap=exactmap and mem=X values to configure the memory mapping

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread Toshi Kani
On Mon, 2014-01-13 at 18:39 -0500, Prarit Bhargava wrote: On 01/13/2014 03:31 PM, KOSAKI Motohiro wrote: On Sun, Jan 12, 2014 at 6:46 PM, Prarit Bhargava pra...@redhat.com wrote: On 01/11/2014 11:35 AM, 7egg...@gmx.de wrote: On Fri, 10 Jan 2014, Prarit Bhargava wrote: kdump

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread H. Peter Anvin
On 01/13/2014 04:33 PM, Toshi Kani wrote: I do not think it makes sense. You needed memmap=exactmap as a workaround because the kernel did not boot with the firmware's memory info. So, it's broken, and you requested the kernel to ignore the firmware info. Why do you think memory hotplug

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread Toshi Kani
On Mon, 2014-01-13 at 16:53 -0800, H. Peter Anvin wrote: On 01/13/2014 04:33 PM, Toshi Kani wrote: I do not think it makes sense. You needed memmap=exactmap as a workaround because the kernel did not boot with the firmware's memory info. So, it's broken, and you requested the kernel to

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread H. Peter Anvin
On 01/13/2014 05:09 PM, Toshi Kani wrote: In majority of the cases, memmap=exactmap is used for kdump and the firmware info is sane. So, I think we should keep NUMA enabled since it could be useful when multiple CPUs are enabled for kdump. Rather unlikely since all of the kdump memory is

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread Toshi Kani
On Mon, 2014-01-13 at 17:29 -0800, H. Peter Anvin wrote: On 01/13/2014 05:09 PM, Toshi Kani wrote: In majority of the cases, memmap=exactmap is used for kdump and the firmware info is sane. So, I think we should keep NUMA enabled since it could be useful when multiple CPUs are enabled

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread Dave Young
On 01/13/14 at 06:09pm, Toshi Kani wrote: On Mon, 2014-01-13 at 16:53 -0800, H. Peter Anvin wrote: On 01/13/2014 04:33 PM, Toshi Kani wrote: I do not think it makes sense. You needed memmap=exactmap as a workaround because the kernel did not boot with the firmware's memory info.

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-13 Thread Toshi Kani
On Tue, 2014-01-14 at 09:52 +0800, Dave Young wrote: On 01/13/14 at 06:09pm, Toshi Kani wrote: On Mon, 2014-01-13 at 16:53 -0800, H. Peter Anvin wrote: On 01/13/2014 04:33 PM, Toshi Kani wrote: I do not think it makes sense. You needed memmap=exactmap as a workaround because

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-12 Thread Prarit Bhargava
On 01/11/2014 11:35 AM, 7egg...@gmx.de wrote: > > > On Fri, 10 Jan 2014, Prarit Bhargava wrote: > >> kdump uses memmap=exactmap and mem=X values to configure the memory >> mapping for the kdump kernel. If memory is hotadded during the boot of >> the kdump kernel it is possible that the page

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-12 Thread Prarit Bhargava
On 01/11/2014 11:35 AM, 7egg...@gmx.de wrote: On Fri, 10 Jan 2014, Prarit Bhargava wrote: kdump uses memmap=exactmap and mem=X values to configure the memory mapping for the kdump kernel. If memory is hotadded during the boot of the kdump kernel it is possible that the page tables for

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-11 Thread 7eggert
On Fri, 10 Jan 2014, Prarit Bhargava wrote: > kdump uses memmap=exactmap and mem=X values to configure the memory > mapping for the kdump kernel. If memory is hotadded during the boot of > the kdump kernel it is possible that the page tables for the new memory > cause the kdump kernel to run

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-11 Thread 7eggert
On Fri, 10 Jan 2014, Prarit Bhargava wrote: kdump uses memmap=exactmap and mem=X values to configure the memory mapping for the kdump kernel. If memory is hotadded during the boot of the kdump kernel it is possible that the page tables for the new memory cause the kdump kernel to run out

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-10 Thread Toshi Kani
On Fri, 2014-01-10 at 14:04 -0500, Prarit Bhargava wrote: : > arch/x86/kernel/e820.c | 10 +- > drivers/acpi/acpi_memhotplug.c |7 ++- > include/linux/memory_hotplug.h |3 +++ > 3 files changed, 18 insertions(+), 2 deletions(-) > > diff --git

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-10 Thread Vivek Goyal
On Fri, Jan 10, 2014 at 02:04:58PM -0500, Prarit Bhargava wrote: > kdump uses memmap=exactmap and mem=X values Minor nit. Kdump only uses memmap=exactmap and not mem=X. mem=X is there for debugging. So lets fix the changelog. [..] > static int __init parse_memmap_opt(char *str) > { > +

[PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-10 Thread Prarit Bhargava
kdump uses memmap=exactmap and mem=X values to configure the memory mapping for the kdump kernel. If memory is hotadded during the boot of the kdump kernel it is possible that the page tables for the new memory cause the kdump kernel to run out of memory. Since the user has specified a specific

[PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-10 Thread Prarit Bhargava
kdump uses memmap=exactmap and mem=X values to configure the memory mapping for the kdump kernel. If memory is hotadded during the boot of the kdump kernel it is possible that the page tables for the new memory cause the kdump kernel to run out of memory. Since the user has specified a specific

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-10 Thread Vivek Goyal
On Fri, Jan 10, 2014 at 02:04:58PM -0500, Prarit Bhargava wrote: kdump uses memmap=exactmap and mem=X values Minor nit. Kdump only uses memmap=exactmap and not mem=X. mem=X is there for debugging. So lets fix the changelog. [..] static int __init parse_memmap_opt(char *str) { + int

Re: [PATCH 2/2] x86, e820 disable ACPI Memory Hotplug if memory mapping is specified by user [v2]

2014-01-10 Thread Toshi Kani
On Fri, 2014-01-10 at 14:04 -0500, Prarit Bhargava wrote: : arch/x86/kernel/e820.c | 10 +- drivers/acpi/acpi_memhotplug.c |7 ++- include/linux/memory_hotplug.h |3 +++ 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/e820.c