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| author | Mike Rapoport <rppt@linux.ibm.com> | 2021-06-29 05:42:43 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-29 20:53:55 +0300 |
| commit | e7793e53901b31a06db534679e77c0cdeab260a2 (patch) | |
| tree | 40a3312efc91ff8fb4c093f5d48d2e0079a6b6be /arch | |
| parent | fdb7d9b7acd02f573ae4fc0c7772f6b5c6b1bad0 (diff) | |
| download | linux-e7793e53901b31a06db534679e77c0cdeab260a2.tar.xz | |
arc: update comment about HIGHMEM implementation
Arc does not use DISCONTIGMEM to implement high memory, update the comment
describing how high memory works to reflect this.
Link: https://lkml.kernel.org/r/20210608091316.3622-3-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arc/mm/init.c | 13 |
1 files 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); |