Messages in this thread |  | | From | Mike Rapoport <> | Subject | [RFC/RFT PATCH v2 0/1] arc: add sparsemem support | Date | Thu, 9 Jul 2020 16:44:11 +0300 |
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From: Mike Rapoport <rppt@linux.ibm.com>
Hi,
It took me a while to get back to it, but better late than never :)
This patch adds SPARSEMEM support as an alternative to DISCONTIGMEM in the case when there are two DRAM banks populated.
I've verified that it boots on nsim, but I could not find a way to make nsim emulate two memory banks.
There is slight improvement in the resulting kernel size for nsim_700_defconfig with CONFIG_HIGHMEM=y.
If sparse actually works on a system with 2 DRAM banks and does not introduce performance regression, I suggest to update this patch to replace DISCONTIGMEM with SPARSEMEM on arc.
$ size discontig/vmlinux sparse/vmlinux text data bss dec hex filename 3894379 1093092 244932 5232403 4fd713 discontig/vmlinux 3879040 1093964 244956 5217960 4f9ea8 sparse/vmlinux
$ ./scripts/bloat-o-meter ~/tmp/arc/discontig/vmlinux ~/tmp/arc/sparse/vmlinux add/remove: 35/23 grow/shrink: 35/384 up/down: 8110/-26438 (-18328) ... Total: Before=4282217, After=4263889, chg -0.43%
Mike Rapoport (1): arc: add sparsemem support
arch/arc/Kconfig | 10 ++++++++++ arch/arc/include/asm/sparsemem.h | 13 +++++++++++++ arch/arc/mm/init.c | 7 ++++++- 3 files changed, 29 insertions(+), 1 deletion(-) create mode 100644 arch/arc/include/asm/sparsemem.h
-- 2.26.2
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