From e73ad5ff2f76da25390e9607cb549691639330c3 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@kernel.org>
Date: Mon, 22 May 2017 15:30:03 -0700
Subject: mm, x86/mm: Make the batched unmap TLB flush API more generic
try_to_unmap_flush() used to open-code a rather x86-centric flush
sequence: local_flush_tlb() + flush_tlb_others(). Rearrange the
code so that the arch (only x86 for now) provides
arch_tlbbatch_add_mm() and arch_tlbbatch_flush() and the core code
calls those functions instead.
I'll want this for x86 because, to enable address space ids, I can't
support the flush_tlb_others() mode used by exising
try_to_unmap_flush() implementation with good performance. I can
support the new API fairly easily, though.
I imagine that other architectures may be in a similar position.
Architectures with strong remote flush primitives (arm64?) may have
even worse performance problems with flush_tlb_others() the way that
try_to_unmap_flush() uses it.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/19f25a8581f9fb77876b7ff3b001f89835e34ea3.1495492063.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
include/linux/mm_types_task.h | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
(limited to 'include/linux')
diff --git a/include/linux/mm_types_task.h b/include/linux/mm_types_task.h
index 136dfdf63ba1..fc412fbd80bd 100644
--- a/include/linux/mm_types_task.h
+++ b/include/linux/mm_types_task.h
@@ -14,6 +14,10 @@
#include <asm/page.h>
+#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
+#include <asm/tlbbatch.h>
+#endif
+
#define USE_SPLIT_PTE_PTLOCKS (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS)
#define USE_SPLIT_PMD_PTLOCKS (USE_SPLIT_PTE_PTLOCKS && \
IS_ENABLED(CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK))
@@ -67,12 +71,15 @@ struct page_frag {
struct tlbflush_unmap_batch {
#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
/*
- * Each bit set is a CPU that potentially has a TLB entry for one of
- * the PFNs being flushed. See set_tlb_ubc_flush_pending().
+ * The arch code makes the following promise: generic code can modify a
+ * PTE, then call arch_tlbbatch_add_mm() (which internally provides all
+ * needed barriers), then call arch_tlbbatch_flush(), and the entries
+ * will be flushed on all CPUs by the time that arch_tlbbatch_flush()
+ * returns.
*/
- struct cpumask cpumask;
+ struct arch_tlbflush_unmap_batch arch;
- /* True if any bit in cpumask is set */
+ /* True if a flush is needed. */
bool flush_required;
/*
--
cgit v1.2.3
From 5dd0b16cdaff9b94da06074d5888b03235c0bf17 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@kernel.org>
Date: Mon, 5 Jun 2017 07:40:25 -0700
Subject: mm/vmstat: Make NR_TLB_REMOTE_FLUSH_RECEIVED available even on UP
This fixes CONFIG_SMP=n, CONFIG_DEBUG_TLBFLUSH=y without introducing
further #ifdef soup. Caught by a Kbuild bot randconfig build.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: ce4a4e565f52 ("x86/mm: Remove the UP asm/tlbflush.h code, always use the (formerly) SMP code")
Link: http://lkml.kernel.org/r/76da9a3cc4415996f2ad2c905b93414add322021.1496673616.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
include/linux/vm_event_item.h | 2 --
1 file changed, 2 deletions(-)
(limited to 'include/linux')
diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index d84ae90ccd5c..be3ab2d13adf 100644
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -93,10 +93,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
#endif
#endif
#ifdef CONFIG_DEBUG_TLBFLUSH
-#ifdef CONFIG_SMP
NR_TLB_REMOTE_FLUSH, /* cpu tried to flush others' tlbs */
NR_TLB_REMOTE_FLUSH_RECEIVED,/* cpu received ipi for flush */
-#endif /* CONFIG_SMP */
NR_TLB_LOCAL_FLUSH_ALL,
NR_TLB_LOCAL_FLUSH_ONE,
#endif /* CONFIG_DEBUG_TLBFLUSH */
--
cgit v1.2.3