ping... On 11/13/2013 09:50 PM, Zhang Yanfei wrote: > Hello guys, > > Could anyone help reviewing this part? > > The first part has been merged into linus's tree. And I've tried to apply this part > to today's linus tree: > > commit 42a2d923cc349583ebf6fdd52a7d35e1c2f7e6bd > Merge: 5cbb3d2 75ecab1 > Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Date: Wed Nov 13 17:40:34 2013 +0900 > > Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next > > No conflict, no compiling error and it works well. > > Tejun, any comments? > > On 10/12/2013 02:00 PM, Zhang Yanfei wrote: >> Hello guys, this is the part2 of our memory hotplug work. This part >> is based on the part1: >> "x86, memblock: Allocate memory near kernel image before SRAT parsed" >> which is base on 3.12-rc4. >> >> You could refer part1 from: https://lkml.org/lkml/2013/10/10/644 >> >> Any comments are welcome! Thanks! >> >> [Problem] >> >> The current Linux cannot migrate pages used by the kerenl because >> of the kernel direct mapping. In Linux kernel space, va = pa + PAGE_OFFSET. >> When the pa is changed, we cannot simply update the pagetable and >> keep the va unmodified. So the kernel pages are not migratable. >> >> There are also some other issues will cause the kernel pages not migratable. >> For example, the physical address may be cached somewhere and will be used. >> It is not to update all the caches. >> >> When doing memory hotplug in Linux, we first migrate all the pages in one >> memory device somewhere else, and then remove the device. But if pages are >> used by the kernel, they are not migratable. As a result, memory used by >> the kernel cannot be hot-removed. >> >> Modifying the kernel direct mapping mechanism is too difficult to do. And >> it may cause the kernel performance down and unstable. So we use the following >> way to do memory hotplug. >> >> >> [What we are doing] >> >> In Linux, memory in one numa node is divided into several zones. One of the >> zones is ZONE_MOVABLE, which the kernel won't use. >> >> In order to implement memory hotplug in Linux, we are going to arrange all >> hotpluggable memory in ZONE_MOVABLE so that the kernel won't use these memory. >> >> To do this, we need ACPI's help. >> >> >> [How we do this] >> >> In ACPI, SRAT(System Resource Affinity Table) contains NUMA info. The memory >> affinities in SRAT record every memory range in the system, and also, flags >> specifying if the memory range is hotpluggable. >> (Please refer to ACPI spec 5.0 5.2.16) >> >> With the help of SRAT, we have to do the following two things to achieve our >> goal: >> >> 1. When doing memory hot-add, allow the users arranging hotpluggable as >> ZONE_MOVABLE. >> (This has been done by the MOVABLE_NODE functionality in Linux.) >> >> 2. when the system is booting, prevent bootmem allocator from allocating >> hotpluggable memory for the kernel before the memory initialization >> finishes. >> (This is what we are going to do. See below.) >> >> >> [About this patch-set] >> >> In previous part's patches, we have made the kernel allocate memory near >> kernel image before SRAT parsed to avoid allocating hotpluggable memory >> for kernel. So this patch-set does the following things: >> >> 1. Improve memblock to support flags, which are used to indicate different >> memory type. >> >> 2. Mark all hotpluggable memory in memblock.memory[]. >> >> 3. Make the default memblock allocator skip hotpluggable memory. >> >> 4. Improve "movable_node" boot option to have higher priority of movablecore >> and kernelcore boot option. >> >> Change log v1 -> v2: >> 1. Rebase this part on the v7 version of part1 >> 2. Fix bug: If movable_node boot option not specified, memblock still >> checks hotpluggable memory when allocating memory. >> >> Tang Chen (7): >> memblock, numa: Introduce flag into memblock >> memblock, mem_hotplug: Introduce MEMBLOCK_HOTPLUG flag to mark >> hotpluggable regions >> memblock: Make memblock_set_node() support different memblock_type >> acpi, numa, mem_hotplug: Mark hotpluggable memory in memblock >> acpi, numa, mem_hotplug: Mark all nodes the kernel resides >> un-hotpluggable >> memblock, mem_hotplug: Make memblock skip hotpluggable regions if >> needed >> x86, numa, acpi, memory-hotplug: Make movable_node have higher >> priority >> >> Yasuaki Ishimatsu (1): >> x86: get pg_data_t's memory from other node >> >> arch/metag/mm/init.c | 3 +- >> arch/metag/mm/numa.c | 3 +- >> arch/microblaze/mm/init.c | 3 +- >> arch/powerpc/mm/mem.c | 2 +- >> arch/powerpc/mm/numa.c | 8 ++- >> arch/sh/kernel/setup.c | 4 +- >> arch/sparc/mm/init_64.c | 5 +- >> arch/x86/mm/init_32.c | 2 +- >> arch/x86/mm/init_64.c | 2 +- >> arch/x86/mm/numa.c | 63 +++++++++++++++++++++-- >> arch/x86/mm/srat.c | 5 ++ >> include/linux/memblock.h | 39 ++++++++++++++- >> mm/memblock.c | 123 ++++++++++++++++++++++++++++++++++++++------- >> mm/memory_hotplug.c | 1 + >> mm/page_alloc.c | 28 ++++++++++- >> 15 files changed, 252 insertions(+), 39 deletions(-) >> > > -- Thanks. Zhang Yanfei -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>