Messages in this thread | | | Date | Thu, 21 Feb 2013 11:03:46 +0800 | From | Tang Chen <> | Subject | Re: [Bug fix PATCH 0/2] Make whatever node kernel resides in un-hotpluggable. |
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On 02/21/2013 05:36 AM, Andrew Morton wrote: > On Wed, 20 Feb 2013 19:00:54 +0800 > Tang Chen<tangchen@cn.fujitsu.com> wrote: > >> As mentioned by HPA before, when we are using movablemem_map=acpi, if all the >> memory in SRAT is hotpluggable, then the kernel will have no memory to use, and >> will fail to boot. >> >> Before parsing SRAT, memblock has already reserved some memory in memblock.reserve, >> which is used by the kernel, such as storing the kernel image. We are not able to >> prevent the kernel from using these memory. So, these 2 patches make the node which >> the kernel resides in un-hotpluggable. > > I'm planning to roll all these into a single commit: > > acpi-memory-hotplug-support-getting-hotplug-info-from-srat.patch > acpi-memory-hotplug-support-getting-hotplug-info-from-srat-fix.patch > acpi-memory-hotplug-support-getting-hotplug-info-from-srat-fix-fix.patch > acpi-memory-hotplug-support-getting-hotplug-info-from-srat-fix-fix-fix.patch > acpi-memory-hotplug-support-getting-hotplug-info-from-srat-fix-fix-fix-fix.patch > acpi-memory-hotplug-support-getting-hotplug-info-from-srat-fix-fix-fix-fix-fix.patch > > for reasons of tree-cleanliness and to avoid bisection holes. They're > at http://ozlabs.org/~akpm/mmots/broken-out/. > > Can you please check the changelog for > acpi-memory-hotplug-support-getting-hotplug-info-from-srat.patch to see > if it needs any updates due to all the fixup patches? If so, please > send me the new changelog, thanks.
Hi Andrew,
Please use the following changelog for acpi-memory-hotplug-support-getting-hotplug-info-from-srat.patch
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We now provide an option for users who don't want to specify physical memory address in kernel commandline.
/* * For movablemem_map=acpi: * * SRAT: |_____| |_____| |_________| |_________| ...... * node id: 0 1 1 2 * hotpluggable: n y y n * movablemem_map: |_____| |_________| * * Using movablemem_map, we can prevent memblock from allocating memory * on ZONE_MOVABLE at boot time. */
So user just specify movablemem_map=acpi, and the kernel will use hotpluggable info in SRAT to determine which memory ranges should be set as ZONE_MOVABLE.
If all the memory ranges in SRAT is hotpluggable, then no memory can be used by kernel. But before parsing SRAT, memblock has already reserve some memory ranges for other purposes, such as for kernel image, and so on. We cannot prevent kernel from using these memory. So we need to exclude these ranges even if these memory is hotpluggable.
Furthermore, there could be several memory ranges in the single node which the kernel resides in. We may skip one range that have memory reserved by memblock, but if the rest of memory is too small, then the kernel will fail to boot. So, make the whole node which the kernel resides in un-hotpluggable. Then the kernel has enough memory to use.
NOTE: Using this way will cause NUMA performance down because the whole node will be set as ZONE_MOVABLE, and kernel cannot use memory on it. If users don't want to lose NUMA performance, just don't use it.
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> > Also, please review the changelogging for these:
The following xxx-fix-... patches will also be rolled, right ? I'll post the changelogs later.
Thanks. :)
> > page_alloc-add-movable_memmap-kernel-parameter.patch > page_alloc-add-movable_memmap-kernel-parameter-fix.patch > page_alloc-add-movable_memmap-kernel-parameter-fix-fix.patch > page_alloc-add-movable_memmap-kernel-parameter-fix-fix-checkpatch-fixes.patch > page_alloc-add-movable_memmap-kernel-parameter-fix-fix-fix.patch > page_alloc-add-movable_memmap-kernel-parameter-rename-movablecore_map-to-movablemem_map.patch > > memory-hotplug-remove-sys-firmware-memmap-x-sysfs.patch > memory-hotplug-remove-sys-firmware-memmap-x-sysfs-fix.patch > memory-hotplug-remove-sys-firmware-memmap-x-sysfs-fix-fix.patch > memory-hotplug-remove-sys-firmware-memmap-x-sysfs-fix-fix-fix.patch > memory-hotplug-remove-sys-firmware-memmap-x-sysfs-fix-fix-fix-fix.patch > memory-hotplug-remove-sys-firmware-memmap-x-sysfs-fix-fix-fix-fix-fix.patch > > memory-hotplug-implement-register_page_bootmem_info_section-of-sparse-vmemmap.patch > memory-hotplug-implement-register_page_bootmem_info_section-of-sparse-vmemmap-fix.patch > memory-hotplug-implement-register_page_bootmem_info_section-of-sparse-vmemmap-fix-fix.patch > memory-hotplug-implement-register_page_bootmem_info_section-of-sparse-vmemmap-fix-fix-fix.patch > memory-hotplug-implement-register_page_bootmem_info_section-of-sparse-vmemmap-fix-fix-fix-fix.patch > > memory-hotplug-common-apis-to-support-page-tables-hot-remove.patch > memory-hotplug-common-apis-to-support-page-tables-hot-remove-fix.patch > memory-hotplug-common-apis-to-support-page-tables-hot-remove-fix-fix.patch > memory-hotplug-common-apis-to-support-page-tables-hot-remove-fix-fix-fix.patch > memory-hotplug-common-apis-to-support-page-tables-hot-remove-fix-fix-fix-fix.patch > memory-hotplug-common-apis-to-support-page-tables-hot-remove-fix-fix-fix-fix-fix.patch > memory-hotplug-common-apis-to-support-page-tables-hot-remove-fix-fix-fix-fix-fix-fix.patch > memory-hotplug-common-apis-to-support-page-tables-hot-remove-fix-fix-fix-fix-fix-fix-fix.patch > > acpi-memory-hotplug-parse-srat-before-memblock-is-ready.patch > acpi-memory-hotplug-parse-srat-before-memblock-is-ready-fix.patch > acpi-memory-hotplug-parse-srat-before-memblock-is-ready-fix-fix.patch > > > and while we're there, let's pause to admire how prescient I was in > refusing to merge all this into 3.8-rc1 :) >
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