From: Sudarshan Rajagopalan <sudaraja@codeaurora.org>
To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Cc: Sudarshan Rajagopalan <sudaraja@codeaurora.org>,
Gavin Shan <gshan@redhat.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Logan Gunthorpe <logang@deltatee.com>,
David Hildenbrand <david@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Steven Price <steven.price@arm.com>
Subject: [PATCH v3] arm64/mm: add fallback option to allocate virtually contiguous memory
Date: Mon, 12 Oct 2020 16:05:58 -0700 [thread overview]
Message-ID: <339118202d0a4741ec22f215830dc8d9ba1ccd49.1602542734.git.sudaraja@codeaurora.org> (raw)
In-Reply-To: <cover.1602542734.git.sudaraja@codeaurora.org>
When section mappings are enabled, we allocate vmemmap pages from physically
continuous memory of size PMD_SIZE using vmemmap_alloc_block_buf(). Section
mappings are good to reduce TLB pressure. But when system is highly fragmented
and memory blocks are being hot-added at runtime, its possible that such
physically continuous memory allocations can fail. Rather than failing the
memory hot-add procedure, add a fallback option to allocate vmemmap pages from
discontinuous pages using vmemmap_populate_basepages().
Signed-off-by: Sudarshan Rajagopalan <sudaraja@codeaurora.org>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Price <steven.price@arm.com>
---
arch/arm64/mm/mmu.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 75df62fea1b6..44486fd0e883 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1121,8 +1121,11 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
void *p = NULL;
p = vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
- if (!p)
- return -ENOMEM;
+ if (!p) {
+ if (vmemmap_populate_basepages(addr, next, node, altmap))
+ return -ENOMEM;
+ continue;
+ }
pmd_set_huge(pmdp, __pa(p), __pgprot(PROT_SECT_NORMAL));
} else
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2020-10-12 23:06 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-12 23:05 [PATCH v3] arm64/mm: add fallback option to allocate virtually contiguous memory Sudarshan Rajagopalan
2020-10-12 23:05 ` Sudarshan Rajagopalan [this message]
2020-10-13 11:38 ` Anshuman Khandual
2020-10-15 0:54 ` Sudarshan Rajagopalan
-- strict thread matches above, loose matches on Subject: below --
2020-10-15 0:51 Sudarshan Rajagopalan
2020-10-15 0:51 ` Sudarshan Rajagopalan
2020-10-15 8:36 ` Will Deacon
2020-10-16 18:49 ` Sudarshan Rajagopalan
2020-10-01 20:16 [PATCH v3] arm64/mm: add fallback option to allocate virtually Sudarshan Rajagopalan
2020-10-01 20:16 ` [PATCH v3] arm64/mm: add fallback option to allocate virtually contiguous memory Sudarshan Rajagopalan
2020-10-06 3:36 ` Anshuman Khandual
2020-10-12 2:54 ` Gavin Shan
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