From d4dd236a95468bcb76f46afe3dd35d3cd401909e Mon Sep 17 00:00:00 2001 From: Arun KS Date: Mon, 9 Oct 2017 16:39:57 +0530 Subject: [PATCH] arm64: Add fallback option during memory hot add Section mapping is good for TLB. But sometimes, when system is low on physically continuous memory, this can cause memory allocation failures. Add a fallback option to allocate vmemmap pages from discontinuous pages. Change-Id: Ide921c36c1e8980a8af047e2c991310405804858 Signed-off-by: Arun KS Signed-off-by: Vinayak Menon Signed-off-by: Sudarshan Rajagopalan [swatsrid@codeaurora.org: Fix merge conflicts] Signed-off-by: Swathi Sridhar [isaacm@codeaurora.org: resolve build errors due to API changes] Signed-off-by: Isaac J. Manjarres --- arch/arm64/mm/mmu.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index cf2547349826..5f61af947e46 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1116,6 +1116,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, pgd_t *pgdp; pud_t *pudp; pmd_t *pmdp; + int ret = 0; do { next = pmd_addr_end(addr, end); @@ -1133,15 +1134,23 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, void *p = NULL; p = vmemmap_alloc_block_buf(PMD_SIZE, node); - if (!p) - return -ENOMEM; + if (!p) { +#ifdef CONFIG_MEMORY_HOTPLUG + vmemmap_free(start, end, altmap); +#endif + ret = -ENOMEM; + break; + } pmd_set_huge(pmdp, __pa(p), __pgprot(PROT_SECT_NORMAL)); } else vmemmap_verify((pte_t *)pmdp, node, addr, next); } while (addr = next, addr != end); - return 0; + if (ret) + return vmemmap_populate_basepages(start, end, node); + else + return ret; } #endif /* !ARM64_SWAPPER_USES_SECTION_MAPS */ void vmemmap_free(unsigned long start, unsigned long end,