From: Yu Zhao <yuzhao@google.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Mark Rutland <mark.rutland@arm.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Nick Piggin <npiggin@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Joel Fernandes <joel@joelfernandes.org>,
"Kirill A . Shutemov" <kirill@shutemov.name>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Chintan Pandya <cpandya@codeaurora.org>,
Jun Yao <yaojun8558363@gmail.com>,
Laura Abbott <labbott@redhat.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
linux-mm@kvack.org, Yu Zhao <yuzhao@google.com>
Subject: [PATCH v3 2/3] arm64: mm: don't call page table ctors for init_mm
Date: Sat, 9 Mar 2019 18:19:05 -0700 [thread overview]
Message-ID: <20190310011906.254635-2-yuzhao@google.com> (raw)
In-Reply-To: <20190310011906.254635-1-yuzhao@google.com>
init_mm doesn't require page table lock to be initialized at
any level. Add a separate page table allocator for it, and the
new one skips page table ctors.
The ctors allocate memory when ALLOC_SPLIT_PTLOCKS is set. Not
calling them avoids memory leak in case we call pte_free_kernel()
on init_mm.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Yu Zhao <yuzhao@google.com>
---
arch/arm64/mm/mmu.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index f704b291f2c5..d1dc2a2777aa 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -370,6 +370,16 @@ static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
} while (pgdp++, addr = next, addr != end);
}
+static phys_addr_t pgd_kernel_pgtable_alloc(int shift)
+{
+ void *ptr = (void *)__get_free_page(PGALLOC_GFP);
+ BUG_ON(!ptr);
+
+ /* Ensure the zeroed page is visible to the page table walker */
+ dsb(ishst);
+ return __pa(ptr);
+}
+
static phys_addr_t pgd_pgtable_alloc(int shift)
{
void *ptr = (void *)__get_free_page(PGALLOC_GFP);
@@ -594,7 +604,7 @@ static int __init map_entry_trampoline(void)
/* Map only the text into the trampoline page table */
memset(tramp_pg_dir, 0, PGD_SIZE);
__create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE,
- prot, pgd_pgtable_alloc, 0);
+ prot, pgd_kernel_pgtable_alloc, 0);
/* Map both the text and data into the kernel page table */
__set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot);
@@ -1070,7 +1080,8 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
__create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start),
- size, PAGE_KERNEL, pgd_pgtable_alloc, flags);
+ size, PAGE_KERNEL, pgd_kernel_pgtable_alloc,
+ flags);
return __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT,
altmap, want_memblock);
--
2.21.0.360.g471c308f928-goog
next prev parent reply other threads:[~2019-03-10 1:19 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-14 21:16 [PATCH] arm64: mm: enable per pmd page table lock Yu Zhao
2019-02-18 15:12 ` Will Deacon
2019-02-18 19:49 ` Yu Zhao
2019-02-18 20:48 ` Yu Zhao
2019-02-19 4:09 ` Anshuman Khandual
2019-02-18 23:13 ` [PATCH v2 1/3] arm64: mm: use appropriate ctors for page tables Yu Zhao
2019-02-18 23:13 ` [PATCH v2 2/3] arm64: mm: don't call page table ctors for init_mm Yu Zhao
2019-02-26 15:13 ` Mark Rutland
2019-03-09 3:52 ` Yu Zhao
2019-02-18 23:13 ` [PATCH v2 3/3] arm64: mm: enable per pmd page table lock Yu Zhao
2019-02-19 4:21 ` [PATCH v2 1/3] arm64: mm: use appropriate ctors for page tables Anshuman Khandual
2019-02-19 5:32 ` Yu Zhao
2019-02-19 6:17 ` Anshuman Khandual
2019-02-19 22:28 ` Yu Zhao
2019-02-20 10:27 ` Anshuman Khandual
2019-02-20 12:24 ` Matthew Wilcox
2019-02-20 20:22 ` Yu Zhao
2019-02-20 20:59 ` Matthew Wilcox
2019-02-20 1:34 ` Matthew Wilcox
2019-02-20 3:20 ` Anshuman Khandual
2019-02-20 21:03 ` Matthew Wilcox
2019-02-26 15:12 ` Mark Rutland
2019-03-09 4:01 ` Yu Zhao
2019-03-10 1:19 ` [PATCH v3 " Yu Zhao
2019-03-10 1:19 ` Yu Zhao [this message]
2019-03-10 1:19 ` [PATCH v3 3/3] arm64: mm: enable per pmd page table lock Yu Zhao
2019-03-11 8:28 ` Anshuman Khandual
2019-03-11 23:10 ` Yu Zhao
2019-03-11 12:12 ` Mark Rutland
2019-03-11 12:57 ` Anshuman Khandual
2019-03-11 23:11 ` Yu Zhao
2019-03-11 7:45 ` [PATCH v3 1/3] arm64: mm: use appropriate ctors for page tables Anshuman Khandual
2019-03-11 23:23 ` Yu Zhao
2019-03-12 0:57 ` [PATCH v4 1/4] " Yu Zhao
2019-03-12 0:57 ` [PATCH v4 2/4] arm64: mm: don't call page table ctors for init_mm Yu Zhao
2019-03-12 0:57 ` [PATCH v4 3/4] arm64: mm: call ctor for stage2 pmd page Yu Zhao
2019-03-12 0:57 ` [PATCH v4 4/4] arm64: mm: enable per pmd page table lock Yu Zhao
2019-02-19 3:08 ` [PATCH] " Anshuman Khandual
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