[PATCH 2/9] arc: update comment about HIGHMEM implementation
From: Mike Rapoport <rppt@kernel.org>
Date: 2021-06-02 10:54:25
Also in:
kexec, linux-arch, linux-arm-kernel, linux-doc, linux-m68k, linux-mips, linux-mm, linux-riscv, linux-s390, linux-sh, linuxppc-dev, lkml, sparclinux
Subsystem:
synopsys arc architecture, the rest · Maintainers:
Vineet Gupta, Linus Torvalds
From: Mike Rapoport <redacted> Arc does not use DISCONTIGMEM to implement high memory, update the comment describing how high memory works to reflect this. Signed-off-by: Mike Rapoport <redacted> --- arch/arc/mm/init.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index e2ed355438c9..397a201adfe3 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c@@ -139,16 +139,13 @@ void __init setup_arch_memory(void) #ifdef CONFIG_HIGHMEM /* - * Populate a new node with highmem - * * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based) - * than addresses in normal ala low memory (0x8000_0000 based). + * than addresses in normal aka low memory (0x8000_0000 based). * Even with PAE, the huge peripheral space hole would waste a lot of - * mem with single mem_map[]. This warrants a mem_map per region design. - * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM. - * - * DISCONTIGMEM in turns requires multiple nodes. node 0 above is - * populated with normal memory zone while node 1 only has highmem + * mem with single contiguous mem_map[]. + * Thus when HIGHMEM on ARC is enabled the memory map corresponding + * to the hole is freed and ARC specific version of pfn_valid() + * handles the hole in the memory map. */ #ifdef CONFIG_DISCONTIGMEM node_set_online(1);
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2.28.0