arm64: add NUMA emulation support

Message ID	20180824230559.32336-1-shuah@kernel.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org> From: "Shuah Khan (Samsung OSG)" <shuah@kernel.org> To: catalin.marinas@arm.com, will.deacon@arm.com, sudeep.holla@arm.com, ganapatrao.kulkarni@cavium.com Subject: [PATCH] arm64: add NUMA emulation support Date: Fri, 24 Aug 2018 17:05:59 -0600 Message-Id: <20180824230559.32336-1-shuah@kernel.org> Precedence: list Cc: "Shuah Khan \(Samsung OSG\)" <shuah@kernel.org>, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org
Series	arm64: add NUMA emulation support \| expand arm64: add NUMA emulation support

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 29e75b47becd..6e74d9995d24 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -740,6 +740,15 @@ config NUMA local memory of the CPU and add some more NUMA awareness to the kernel. +config NUMA_EMU + bool "NUMA emulation" + depends on NUMA + help + Enable NUMA emulation. A flat machine will be split into virtual + nodes when booted with "numa=fake=N", where N is the number of + nodes, the system RAM will be split into N equal chunks, and + assigned to each node. + config NODES_SHIFT int "Maximum NUMA Nodes (as a power of 2)" range 1 10 diff --git a/arch/arm64/include/asm/numa.h b/arch/arm64/include/asm/numa.h index 626ad01e83bf..16e8cc035872 100644 --- a/arch/arm64/include/asm/numa.h +++ b/arch/arm64/include/asm/numa.h @@ -29,6 +29,14 @@ static inline const struct cpumask *cpumask_of_node(int node) } #endif +#ifdef CONFIG_NUMA_EMU +void arm64_numa_emu_cmdline(char *str); +extern int arm64_numa_emu_init(void); +#else +static inline void arm64_numa_emu_cmdline(char *str) {} +static inline int arm64_numa_emu_init(void) { return -1; } +#endif /* CONFIG_NUMA_EMU */ + void __init arm64_numa_init(void); int __init numa_add_memblk(int nodeid, u64 start, u64 end); void __init numa_set_distance(int from, int to, int distance); diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile index 849c1df3d214..2c8634daeffa 100644 --- a/arch/arm64/mm/Makefile +++ b/arch/arm64/mm/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_ARM64_PTDUMP_CORE) += dump.o obj-$(CONFIG_ARM64_PTDUMP_DEBUGFS) += ptdump_debugfs.o obj-$(CONFIG_NUMA) += numa.o obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o +obj-$(CONFIG_NUMA_EMU) += numa_emu.o KASAN_SANITIZE_physaddr.o += n obj-$(CONFIG_KASAN) += kasan_init.o diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c index 146c04ceaa51..9232f18e3992 100644 --- a/arch/arm64/mm/numa.c +++ b/arch/arm64/mm/numa.c @@ -43,6 +43,8 @@ static __init int numa_parse_early_param(char *opt) return -EINVAL; if (!strncmp(opt, "off", 3)) numa_off = true; + if (!strncmp(opt, "fake=", 5)) + arm64_numa_emu_cmdline(opt + 5); return 0; } @@ -460,6 +462,8 @@ void __init arm64_numa_init(void) return; if (acpi_disabled && !numa_init(of_numa_init)) return; + if (!numa_init(arm64_numa_emu_init)) + return; } numa_init(dummy_numa_init); diff --git a/arch/arm64/mm/numa_emu.c b/arch/arm64/mm/numa_emu.c new file mode 100644 index 000000000000..97217adb029e --- /dev/null +++ b/arch/arm64/mm/numa_emu.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * NUMA Emulation for non-NUMA platforms. + */ + +#include <linux/numa.h> +#include <linux/nodemask.h> +#include <linux/pfn.h> +#include <linux/bootmem.h> +#include <linux/memblock.h> + +#include <asm/numa.h> + +static char *emu_cmdline __initdata; + +/* + * arm64_numa_emu_cmdline - parse early NUMA Emulation params. + */ +void __init arm64_numa_emu_cmdline(char *str) +{ + emu_cmdline = str; +} + +/* + * arm64_numa_emu_init - Initialize NUMA Emulation + * + * Used when NUMA Emulation is enabled on a platform without underlying + * NUMA architecture. + */ +int __init arm64_numa_emu_init(void) +{ + u64 node_size; + int node_cnt = 0; + int mblk_cnt = 0; + int node = 0; + struct memblock_region *mblk; + bool split = false; + int ret; + + pr_info("NUMA emulation init begin\n"); + + if (!emu_cmdline) + return -EINVAL; + /* + * Split the system RAM into N equal chunks. + */ + ret = kstrtoint(emu_cmdline, 0, &node_cnt); + if (ret || node_cnt <= 0) + return -EINVAL; + + if (node_cnt > MAX_NUMNODES) + node_cnt = MAX_NUMNODES; + + node_size = PFN_PHYS(max_pfn) / node_cnt; + pr_info("NUMA emu: Node Size = %#018Lx Node = %d\n", + node_size, node_cnt); + + for_each_memblock(memory, mblk) + mblk_cnt++; + + /* + * Size the node count to match the memory block count to avoid + * splitting memory blocks across nodes. If there is only one + * memory block split it. + */ + if (mblk_cnt <= node_cnt) { + pr_info("NUMA emu: Nodes (%d) >= Memblocks (%d)\n", + node_cnt, mblk_cnt); + if (mblk_cnt == 1) { + split = true; + pr_info("NUMA emu: Splitting single Memory Block\n"); + } else { + node_cnt = mblk_cnt; + pr_info("NUMA emu: Adjust Nodes = Memory Blocks\n"); + } + } + + for_each_memblock(memory, mblk) { + + if (split) { + for (node = 0; node < node_cnt; node++) { + u64 start, end; + + start = mblk->base + node * node_size; + end = start + node_size; + pr_info("Adding an emulation node %d for [mem %#018Lx-%#018Lx]\n", + node, start, end); + ret = numa_add_memblk(node, start, end); + if (!ret) + continue; + pr_err("NUMA emulation init failed\n"); + return ret; + } + break; + } + pr_info("Adding a emulation node %d for [mem %#018Lx-%#018Lx]\n", + node, mblk->base, mblk->base + mblk->size); + ret = numa_add_memblk(node, mblk->base, + mblk->base + mblk->size); + if (!ret) + continue; + pr_err("NUMA emulation init failed\n"); + return ret; + } + pr_info("NUMA: added %d emulation nodes of %#018Lx size each\n", + node_cnt, node_size); + + return 0; +}

arm64: add NUMA emulation support

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