From 41555cc9e2e9778ddc7c0293a4a2e4995e332643 Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Fri, 21 Oct 2022 17:00:30 +0100 Subject: [PATCH] RISC-V: enable sparsemem by default for defconfig on an arch level, RISC-V defaults to FLATMEM. On PolarFire SoC, the memory layout is almost always sparse, with a maximum of 1 GiB at 0x8000_0000 & a possible 16 GiB range at 0x10_0000_0000. The Icicle kit, for example, has 2 GiB of DDR - so there's a big hole in the memory map between the two gigs. Prior to v6.1-rc1, boot times from defconfig builds were pretty bad on Icicle but enabling sparsemem would fix those issues. As of v6.1-rc1, the Icicle kit no longer boots from defconfig builds with the in-kernel devicetree. A change to the memory map resulted in a futher "sparse-ification", producing a splat on boot: OF: fdt: Ignoring memory range 0x80000000 - 0x80200000 Machine model: Microchip PolarFire-SoC Icicle Kit earlycon: ns16550a0 at MMIO32 0x0000000020100000 (options '115200n8') printk: bootconsole [ns16550a0] enabled printk: debug: skip boot console de-registration. efi: UEFI not found. Zone ranges: DMA32 [mem 0x0000000080200000-0x00000000ffffffff] Normal [mem 0x0000000100000000-0x000000107fffffff] Movable zone start for each node Early memory node ranges node 0: [mem 0x0000000080200000-0x00000000bfbfffff] node 0: [mem 0x00000000bfc00000-0x00000000bfffffff] node 0: [mem 0x0000001040000000-0x000000107fffffff] Initmem setup node 0 [mem 0x0000000080200000-0x000000107fffffff] Kernel panic - not syncing: Failed to allocate 1073741824 bytes for node 0 memory map CPU: 0 PID: 0 Comm: swapper Not tainted 5.19.0-dirty #1 Hardware name: Microchip PolarFire-SoC Icicle Kit (DT) Call Trace: [] show_stack+0x30/0x3c [] dump_stack_lvl+0x4a/0x66 [] dump_stack+0x18/0x20 [] panic+0x124/0x2c6 [] free_area_init_core+0x0/0x11e [] free_area_init_node+0xc2/0xf6 [] free_area_init+0x222/0x260 [] misc_mem_init+0x62/0x9a [] setup_arch+0xb0/0xea [] start_kernel+0x88/0x4ee ---[ end Kernel panic - not syncing: Failed to allocate 1073741824 bytes for node 0 memory map ]--- With the aim of keeping defconfig builds booting on icicle, enable SPARSEMEM_MANUAL. Signed-off-by: Conor Dooley Link: https://lore.kernel.org/r/20221021160028.4042304-1-conor@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/configs/defconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/riscv/configs/defconfig b/arch/riscv/configs/defconfig index 05fd5fc..daba5d7 100644 --- a/arch/riscv/configs/defconfig +++ b/arch/riscv/configs/defconfig @@ -38,6 +38,7 @@ CONFIG_KVM=m CONFIG_JUMP_LABEL=y CONFIG_MODULES=y CONFIG_MODULE_UNLOAD=y +CONFIG_SPARSEMEM_MANUAL=y CONFIG_BLK_DEV_THROTTLING=y CONFIG_NET=y CONFIG_PACKET=y -- 2.7.4