From: Peter Zijlstra <peterz@infradead.org>
To: torvalds@linux-foundation.org
Cc: luto@kernel.org, x86@kernel.org, bp@alien8.de,
will.deacon@arm.com, riel@surriel.com, jannh@google.com,
ascannell@google.com, dave.hansen@intel.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Nicholas Piggin <npiggin@gmail.com>,
David Miller <davem@davemloft.net>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Michael Ellerman <mpe@ellerman.id.au>
Subject: Re: [PATCH 3/4] mm/tlb, x86/mm: Support invalidating TLB caches for RCU_TABLE_FREE
Date: Wed, 22 Aug 2018 17:55:27 +0200 [thread overview]
Message-ID: <20180822155527.GF24124@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20180822154046.823850812@infradead.org>
On Wed, Aug 22, 2018 at 05:30:15PM +0200, Peter Zijlstra wrote:
> ARM
> which later used this put an explicit TLB invalidate in their
> __p*_free_tlb() functions, and PowerPC-radix followed that example.
> +/*
> + * If we want tlb_remove_table() to imply TLB invalidates.
> + */
> +static inline void tlb_table_invalidate(struct mmu_gather *tlb)
> +{
> +#ifdef CONFIG_HAVE_RCU_TABLE_INVALIDATE
> + /*
> + * Invalidate page-table caches used by hardware walkers. Then we still
> + * need to RCU-sched wait while freeing the pages because software
> + * walkers can still be in-flight.
> + */
> + __tlb_flush_mmu_tlbonly(tlb);
> +#endif
> +}
Nick, Will is already looking at using this to remove the synchronous
invalidation from __p*_free_tlb() for ARM, could you have a look to see
if PowerPC-radix could benefit from that too?
Basically, using a patch like the below, would give your tlb_flush()
information on if tables were removed or not.
---
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -96,12 +96,22 @@ struct mmu_gather {
#endif
unsigned long start;
unsigned long end;
- /* we are in the middle of an operation to clear
- * a full mm and can make some optimizations */
- unsigned int fullmm : 1,
- /* we have performed an operation which
- * requires a complete flush of the tlb */
- need_flush_all : 1;
+ /*
+ * we are in the middle of an operation to clear
+ * a full mm and can make some optimizations
+ */
+ unsigned int fullmm : 1;
+
+ /*
+ * we have performed an operation which
+ * requires a complete flush of the tlb
+ */
+ unsigned int need_flush_all : 1;
+
+ /*
+ * we have removed page directories
+ */
+ unsigned int freed_tables : 1;
struct mmu_gather_batch *active;
struct mmu_gather_batch local;
@@ -136,6 +146,7 @@ static inline void __tlb_reset_range(str
tlb->start = TASK_SIZE;
tlb->end = 0;
}
+ tlb->freed_tables = 0;
}
static inline void tlb_remove_page_size(struct mmu_gather *tlb,
@@ -269,6 +280,7 @@ static inline void tlb_remove_check_page
#define pte_free_tlb(tlb, ptep, address) \
do { \
__tlb_adjust_range(tlb, address, PAGE_SIZE); \
+ tlb->freed_tables = 1; \
__pte_free_tlb(tlb, ptep, address); \
} while (0)
#endif
@@ -276,7 +288,8 @@ static inline void tlb_remove_check_page
#ifndef pmd_free_tlb
#define pmd_free_tlb(tlb, pmdp, address) \
do { \
- __tlb_adjust_range(tlb, address, PAGE_SIZE); \
+ __tlb_adjust_range(tlb, address, PAGE_SIZE); \
+ tlb->freed_tables = 1; \
__pmd_free_tlb(tlb, pmdp, address); \
} while (0)
#endif
@@ -286,6 +299,7 @@ static inline void tlb_remove_check_page
#define pud_free_tlb(tlb, pudp, address) \
do { \
__tlb_adjust_range(tlb, address, PAGE_SIZE); \
+ tlb->freed_tables = 1; \
__pud_free_tlb(tlb, pudp, address); \
} while (0)
#endif
@@ -295,7 +309,8 @@ static inline void tlb_remove_check_page
#ifndef p4d_free_tlb
#define p4d_free_tlb(tlb, pudp, address) \
do { \
- __tlb_adjust_range(tlb, address, PAGE_SIZE); \
+ __tlb_adjust_range(tlb, address, PAGE_SIZE); \
+ tlb->freed_tables = 1; \
__p4d_free_tlb(tlb, pudp, address); \
} while (0)
#endif
next prev parent reply other threads:[~2018-08-22 15:55 UTC|newest]
Thread overview: 96+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-22 15:30 [PATCH 0/4] x86: TLB invalidate fixes Peter Zijlstra
2018-08-22 15:30 ` [PATCH 1/4] x86/mm/tlb: Revert the recent lazy TLB patches Peter Zijlstra
2018-08-22 21:37 ` Linus Torvalds
2018-08-22 22:11 ` Rik van Riel
2018-08-22 15:30 ` [PATCH 2/4] mm/tlb: Remove tlb_remove_table() non-concurrent condition Peter Zijlstra
2018-08-23 3:31 ` Nicholas Piggin
2018-08-23 3:35 ` Linus Torvalds
2018-08-23 3:44 ` Linus Torvalds
2018-08-23 4:16 ` Nicholas Piggin
2018-08-23 4:54 ` Linus Torvalds
2018-08-23 5:15 ` Nicholas Piggin
2018-08-24 8:42 ` Peter Zijlstra
2018-08-23 13:40 ` Will Deacon
2018-08-22 15:30 ` [PATCH 3/4] mm/tlb, x86/mm: Support invalidating TLB caches for RCU_TABLE_FREE Peter Zijlstra
2018-08-22 15:55 ` Peter Zijlstra [this message]
2018-08-23 3:45 ` Nicholas Piggin
2018-08-23 3:59 ` Linus Torvalds
2018-08-23 4:33 ` Nicholas Piggin
2018-08-23 5:03 ` Linus Torvalds
2018-08-23 5:58 ` Nicholas Piggin
2018-08-23 4:54 ` Benjamin Herrenschmidt
2018-08-23 5:11 ` Linus Torvalds
2018-08-23 5:20 ` Linus Torvalds
2018-08-23 6:48 ` Martin Schwidefsky
2018-08-23 5:21 ` Benjamin Herrenschmidt
2018-08-23 6:15 ` Nicholas Piggin
2018-08-23 13:39 ` Will Deacon
2018-08-24 8:47 ` Peter Zijlstra
2018-08-24 11:32 ` Peter Zijlstra
2018-08-24 11:39 ` Peter Zijlstra
2018-08-27 5:00 ` Nicholas Piggin
2018-08-27 7:47 ` Peter Zijlstra
2018-08-27 8:04 ` Nicholas Piggin
2018-08-27 8:09 ` Benjamin Herrenschmidt
2018-08-27 8:20 ` Peter Zijlstra
2018-08-27 8:54 ` Nicholas Piggin
2018-08-27 9:02 ` Nicholas Piggin
2018-08-27 22:13 ` Benjamin Herrenschmidt
2018-08-27 13:36 ` Rik van Riel
2018-08-27 14:29 ` Nicholas Piggin
2018-08-27 8:57 ` removig ia64, was: " Christoph Hellwig
2018-08-27 11:28 ` Peter Zijlstra
2018-08-27 11:45 ` Jason Duerstock
2018-08-27 11:00 ` Peter Zijlstra
2018-08-30 0:13 ` Vineet Gupta
2018-08-30 10:23 ` Peter Zijlstra
2018-08-24 17:26 ` Nadav Amit
2018-08-24 18:04 ` Peter Zijlstra
2018-08-24 18:35 ` TLB flushes on fixmap changes Nadav Amit
2018-08-24 19:31 ` Linus Torvalds
2018-08-24 20:24 ` Nadav Amit
2018-08-25 0:58 ` Linus Torvalds
2018-08-25 2:29 ` nadav.amit
2018-08-25 4:23 ` Andy Lutomirski
2018-08-26 2:23 ` Masami Hiramatsu
2018-08-26 4:21 ` Andy Lutomirski
2018-08-26 4:43 ` Kees Cook
2018-08-26 5:53 ` Nadav Amit
2018-08-26 14:20 ` Andy Lutomirski
2018-08-26 16:47 ` Kees Cook
2018-08-26 17:25 ` Andy Lutomirski
2018-08-26 20:15 ` Thomas Gleixner
2018-08-26 22:03 ` Kees Cook
2018-08-26 22:15 ` Matthew Wilcox
2018-08-26 22:29 ` Jann Horn
2018-08-26 9:09 ` Peter Zijlstra
2018-08-27 3:03 ` Masami Hiramatsu
2018-08-27 3:26 ` Nadav Amit
2018-08-27 8:05 ` Masami Hiramatsu
2018-08-27 17:34 ` Nadav Amit
2018-08-27 18:45 ` Andy Lutomirski
2018-08-27 18:54 ` Nadav Amit
2018-08-27 18:58 ` Andy Lutomirski
2018-08-27 19:10 ` Nadav Amit
2018-08-27 19:43 ` Nadav Amit
2018-08-27 19:58 ` Andy Lutomirski
2018-08-27 20:16 ` Nadav Amit
2018-08-27 21:55 ` Nadav Amit
2018-08-27 22:32 ` Andy Lutomirski
2018-08-27 22:54 ` Nadav Amit
2018-08-27 23:01 ` Andy Lutomirski
2018-08-28 8:49 ` Masami Hiramatsu
2018-08-28 17:33 ` Nadav Amit
2018-08-27 8:13 ` Peter Zijlstra
2018-08-27 9:39 ` Masami Hiramatsu
2018-08-27 9:55 ` Jann Horn
2018-08-26 22:48 ` Jann Horn
2018-08-24 8:35 ` [PATCH 3/4] mm/tlb, x86/mm: Support invalidating TLB caches for RCU_TABLE_FREE Peter Zijlstra
2018-08-24 13:13 ` Peter Zijlstra
2018-08-24 13:14 ` Peter Zijlstra
2018-08-24 15:49 ` Will Deacon
2018-08-23 23:31 ` Will Deacon
2018-08-22 21:34 ` Linus Torvalds
2018-08-23 8:46 ` Nicholas Piggin
2018-08-22 15:30 ` [PATCH 4/4] x86/mm: Only use tlb_remove_table() for paravirt Peter Zijlstra
2018-08-22 22:12 ` Eduardo Valentin
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