[PATCH] ARM: mm: enforce pageblock alignment when freeing memmap entries at init
From: Larry Bassel <hidden>
Date: 2011-01-21 23:02:01
On 20 Jan 11 15:47, Dima Zavin wrote:
quoted hunk ↗ jump to hunk
On some machines, the nodes do not always start on pageblock boundaries. In these cases it is possible for free_unused_memmap to free mappings for pages inside a pageblock with otherwise valid pages. This presents problems for page migration since it operates on whole pageblocks at a time. Round down bank_start to pageblock boundary so that whole pageblocks always have valid mappings. Signed-off-by: Dima Zavin <redacted> --- arch/arm/mm/init.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-)diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index 5164069..98de5d8 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c@@ -418,7 +418,11 @@ static void __init free_unused_memmap(struct meminfo *mi) for_each_bank(i, mi) { struct membank *bank = &mi->bank[i]; - bank_start = bank_pfn_start(bank); + /* Round bank_start down to the start of a pageblock so that + * all pages in a pageblock always have a mapping. + */ + bank_start = round_down(bank_pfn_start(bank), + MAX_ORDER_NR_PAGES); /* * If we had a previous bank, and there is a space-- 1.7.3.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel at lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
I tested this (booted, ran various commands for about 10 minutes) on a MSM8x50 with the standard memory map and on a MSM8x50 given a synthetic memory map which would be affected by this patch. Tested-by: Larry Bassel <redacted> -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.