From 5b5260902af4cf7d2b8da06ba395a722f6d490fa Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Fri, 14 Dec 2018 14:16:50 -0800 Subject: [PATCH] alpha: fix hang caused by the bootmem removal The conversion of alpha to memblock as the early memory manager caused boot to hang as described at [1]. The issue is caused because for CONFIG_DISCTONTIGMEM=y case, memblock_add() is called using memory start PFN that had been rounded down to the nearest 8Mb and it caused memblock to see more memory that is actually present in the system. Besides, memblock allocates memory from high addresses while bootmem was using low memory, which broke the assumption that early allocations are always accessible by the hardware. This patch ensures that memblock_add() is using the correct PFN for the memory start and forces memblock to use bottom-up allocations. [1] https://lkml.org/lkml/2018/11/22/1032 Link: http://lkml.kernel.org/r/1543233216-25833-1-git-send-email-rppt@linux.ibm.com Reported-by: Meelis Roos Signed-off-by: Mike Rapoport Tested-by: Meelis Roos Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/alpha/kernel/setup.c | 1 + arch/alpha/mm/numa.c | 6 +++--- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c index a37fd99..4b5b1b2 100644 --- a/arch/alpha/kernel/setup.c +++ b/arch/alpha/kernel/setup.c @@ -634,6 +634,7 @@ setup_arch(char **cmdline_p) /* Find our memory. */ setup_memory(kernel_end); + memblock_set_bottom_up(true); /* First guess at cpu cache sizes. Do this before init_arch. */ determine_cpu_caches(cpu->type); diff --git a/arch/alpha/mm/numa.c b/arch/alpha/mm/numa.c index 74846553..d0b7337 100644 --- a/arch/alpha/mm/numa.c +++ b/arch/alpha/mm/numa.c @@ -144,14 +144,14 @@ setup_memory_node(int nid, void *kernel_end) if (!nid && (node_max_pfn < end_kernel_pfn || node_min_pfn > start_kernel_pfn)) panic("kernel loaded out of ram"); + memblock_add(PFN_PHYS(node_min_pfn), + (node_max_pfn - node_min_pfn) << PAGE_SHIFT); + /* Zone start phys-addr must be 2^(MAX_ORDER-1) aligned. Note that we round this down, not up - node memory has much larger alignment than 8Mb, so it's safe. */ node_min_pfn &= ~((1UL << (MAX_ORDER-1))-1); - memblock_add(PFN_PHYS(node_min_pfn), - (node_max_pfn - node_min_pfn) << PAGE_SHIFT); - NODE_DATA(nid)->node_start_pfn = node_min_pfn; NODE_DATA(nid)->node_present_pages = node_max_pfn - node_min_pfn; -- 2.7.4