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From: Will Deacon <will.deacon@arm.com>
To: linux-kernel@vger.kernel.org
Cc: peterz@infradead.org, benh@au1.ibm.com,
	torvalds@linux-foundation.org, npiggin@gmail.com,
	catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org,
	Will Deacon <will.deacon@arm.com>
Subject: [PATCH 04/12] arm64: tlb: Justify non-leaf invalidation in flush_tlb_range()
Date: Thu, 30 Aug 2018 17:15:38 +0100	[thread overview]
Message-ID: <1535645747-9823-5-git-send-email-will.deacon@arm.com> (raw)
In-Reply-To: <1535645747-9823-1-git-send-email-will.deacon@arm.com>

Add a comment to explain why we can't get away with last-level
invalidation in flush_tlb_range()

Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/tlbflush.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index e257f8655b84..ddbf1718669d 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -182,6 +182,10 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma,
 static inline void flush_tlb_range(struct vm_area_struct *vma,
 				   unsigned long start, unsigned long end)
 {
+	/*
+	 * We cannot use leaf-only invalidation here, since we may be invalidating
+	 * table entries as part of collapsing hugepages or moving page tables.
+	 */
 	__flush_tlb_range(vma, start, end, false);
 }
 
-- 
2.1.4


  parent reply	other threads:[~2018-08-30 16:16 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-30 16:15 [PATCH 00/12] Avoid synchronous TLB invalidation for intermediate page-table entries on arm64 Will Deacon
2018-08-30 16:15 ` [PATCH 01/12] arm64: tlb: Use last-level invalidation in flush_tlb_kernel_range() Will Deacon
2018-08-30 16:15 ` [PATCH 02/12] arm64: tlb: Add DSB ISHST prior to TLBI in __flush_tlb_[kernel_]pgtable() Will Deacon
2018-08-30 16:15 ` [PATCH 03/12] arm64: pgtable: Implement p[mu]d_valid() and check in set_p[mu]d() Will Deacon
2018-08-30 16:15 ` Will Deacon [this message]
2018-08-30 16:15 ` [PATCH 05/12] arm64: tlbflush: Allow stride to be specified for __flush_tlb_range() Will Deacon
2018-08-30 16:15 ` [PATCH 06/12] arm64: tlb: Remove redundant !CONFIG_HAVE_RCU_TABLE_FREE code Will Deacon
2018-08-30 16:15 ` [PATCH 07/12] asm-generic/tlb: Guard with #ifdef CONFIG_MMU Will Deacon
2018-08-30 16:15 ` [PATCH 08/12] asm-generic/tlb: Track freeing of page-table directories in struct mmu_gather Will Deacon
2018-08-30 16:15 ` [PATCH 09/12] asm-generic/tlb: Track which levels of the page tables have been cleared Will Deacon
2018-08-31  1:23   ` Nicholas Piggin
2018-08-30 16:15 ` [PATCH 10/12] arm64: tlb: Adjust stride and type of TLBI according to mmu_gather Will Deacon
2018-08-30 16:15 ` [PATCH 11/12] arm64: tlb: Avoid synchronous TLBIs when freeing page tables Will Deacon
2018-08-30 16:15 ` [PATCH 12/12] arm64: tlb: Rewrite stale comment in asm/tlbflush.h Will Deacon
2018-08-30 16:39 ` [PATCH 00/12] Avoid synchronous TLB invalidation for intermediate page-table entries on arm64 Linus Torvalds
2018-08-31  1:00   ` Nicholas Piggin
2018-08-31  1:04     ` Linus Torvalds
2018-08-31  9:54       ` Will Deacon
2018-08-31 10:10         ` Peter Zijlstra
2018-08-31 10:32           ` Nicholas Piggin
2018-08-31 10:49             ` Peter Zijlstra
2018-08-31 11:12               ` Will Deacon
2018-08-31 11:20                 ` Peter Zijlstra
2018-08-31 11:50               ` Nicholas Piggin
2018-09-03 12:52             ` Will Deacon
2018-08-30 17:11 ` Peter Zijlstra

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