From: Michel Lespinasse <michel@lespinasse.org>
To: Linux-MM <linux-mm@kvack.org>,
linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>
Cc: kernel-team@fb.com, Laurent Dufour <ldufour@linux.ibm.com>,
Jerome Glisse <jglisse@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Michal Hocko <mhocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>,
Davidlohr Bueso <dave@stgolabs.net>,
Matthew Wilcox <willy@infradead.org>,
Liam Howlett <liam.howlett@oracle.com>,
Rik van Riel <riel@surriel.com>,
Paul McKenney <paulmck@kernel.org>,
Song Liu <songliubraving@fb.com>,
Suren Baghdasaryan <surenb@google.com>,
Minchan Kim <minchan@google.com>,
Joel Fernandes <joelaf@google.com>,
David Rientjes <rientjes@google.com>,
Axel Rasmussen <axelrasmussen@google.com>,
Andy Lutomirski <luto@kernel.org>,
Michel Lespinasse <michel@lespinasse.org>
Subject: [PATCH v2 23/35] mm: add mmu_notifier_lock
Date: Fri, 28 Jan 2022 05:09:54 -0800 [thread overview]
Message-ID: <20220128131006.67712-24-michel@lespinasse.org> (raw)
In-Reply-To: <20220128131006.67712-1-michel@lespinasse.org>
Introduce mmu_notifier_lock as a per-mm percpu_rw_semaphore,
as well as the code to initialize and destroy it together with the mm.
This lock will be used to prevent races between mmu_notifier_register()
and speculative fault handlers that need to fire MMU notifications
without holding any of the mmap or rmap locks.
Signed-off-by: Michel Lespinasse <michel@lespinasse.org>
---
include/linux/mm_types.h | 6 +++++-
include/linux/mmu_notifier.h | 27 +++++++++++++++++++++++++--
kernel/fork.c | 3 ++-
3 files changed, 32 insertions(+), 4 deletions(-)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 305f05d2a4bc..f77e2dec038d 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -462,6 +462,7 @@ struct vm_area_struct {
} __randomize_layout;
struct kioctx_table;
+struct percpu_rw_semaphore;
struct mm_struct {
struct {
struct vm_area_struct *mmap; /* list of VMAs */
@@ -608,7 +609,10 @@ struct mm_struct {
struct file __rcu *exe_file;
#ifdef CONFIG_MMU_NOTIFIER
struct mmu_notifier_subscriptions *notifier_subscriptions;
-#endif
+#ifdef CONFIG_SPECULATIVE_PAGE_FAULT
+ struct percpu_rw_semaphore *mmu_notifier_lock;
+#endif /* CONFIG_SPECULATIVE_PAGE_FAULT */
+#endif /* CONFIG_MMU_NOTIFIER */
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
pgtable_t pmd_huge_pte; /* protected by page_table_lock */
#endif
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 45fc2c81e370..ace76fe91c0c 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -6,6 +6,8 @@
#include <linux/spinlock.h>
#include <linux/mm_types.h>
#include <linux/mmap_lock.h>
+#include <linux/percpu-rwsem.h>
+#include <linux/slab.h>
#include <linux/srcu.h>
#include <linux/interval_tree.h>
@@ -499,15 +501,35 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
__mmu_notifier_invalidate_range(mm, start, end);
}
-static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
+static inline bool mmu_notifier_subscriptions_init(struct mm_struct *mm)
{
+#ifdef CONFIG_SPECULATIVE_PAGE_FAULT
+ mm->mmu_notifier_lock = kzalloc(sizeof(struct percpu_rw_semaphore), GFP_KERNEL);
+ if (!mm->mmu_notifier_lock)
+ return false;
+ if (percpu_init_rwsem(mm->mmu_notifier_lock)) {
+ kfree(mm->mmu_notifier_lock);
+ return false;
+ }
+#endif
+
mm->notifier_subscriptions = NULL;
+ return true;
}
static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
{
if (mm_has_notifiers(mm))
__mmu_notifier_subscriptions_destroy(mm);
+
+#ifdef CONFIG_SPECULATIVE_PAGE_FAULT
+ if (!in_atomic()) {
+ percpu_free_rwsem(mm->mmu_notifier_lock);
+ kfree(mm->mmu_notifier_lock);
+ } else {
+ percpu_rwsem_async_destroy(mm->mmu_notifier_lock);
+ }
+#endif
}
@@ -724,8 +746,9 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
{
}
-static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
+static inline bool mmu_notifier_subscriptions_init(struct mm_struct *mm)
{
+ return true;
}
static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
diff --git a/kernel/fork.c b/kernel/fork.c
index 2e5f2e8de31a..db92e42d0087 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1069,7 +1069,8 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
mm_init_owner(mm, p);
mm_init_pasid(mm);
RCU_INIT_POINTER(mm->exe_file, NULL);
- mmu_notifier_subscriptions_init(mm);
+ if (!mmu_notifier_subscriptions_init(mm))
+ goto fail_nopgd;
init_tlb_flush_pending(mm);
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
mm->pmd_huge_pte = NULL;
--
2.20.1
next prev parent reply other threads:[~2022-01-28 13:20 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-28 13:09 [PATCH v2 00/35] Speculative page faults Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 01/35] mm: export dump_mm Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 02/35] mmap locking API: mmap_lock_is_contended returns a bool Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 03/35] mmap locking API: name the return values Michel Lespinasse
2022-01-31 16:17 ` Liam Howlett
2022-02-07 17:39 ` Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 04/35] do_anonymous_page: use update_mmu_tlb() Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 05/35] do_anonymous_page: reduce code duplication Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 06/35] mm: introduce CONFIG_SPECULATIVE_PAGE_FAULT Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 07/35] x86/mm: define ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 08/35] mm: add FAULT_FLAG_SPECULATIVE flag Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 09/35] mm: add do_handle_mm_fault() Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 10/35] mm: add per-mm mmap sequence counter for speculative page fault handling Michel Lespinasse
2022-08-25 11:23 ` Pavan Kondeti
2022-01-28 13:09 ` [PATCH v2 11/35] mm: rcu safe vma freeing Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 12/35] mm: separate mmap locked assertion from find_vma Michel Lespinasse
2022-01-29 0:08 ` kernel test robot
2022-01-29 0:33 ` Michel Lespinasse
2022-01-31 14:44 ` Matthew Wilcox
2022-02-04 22:41 ` Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 13/35] x86/mm: attempt speculative mm faults first Michel Lespinasse
2022-02-01 17:16 ` Liam Howlett
2022-02-07 17:39 ` Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 14/35] mm: add speculative_page_walk_begin() and speculative_page_walk_end() Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 15/35] mm: refactor __handle_mm_fault() / handle_pte_fault() Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 16/35] mm: implement speculative handling in __handle_mm_fault() Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 17/35] mm: add pte_map_lock() and pte_spinlock() Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 18/35] mm: implement speculative handling in do_anonymous_page() Michel Lespinasse
2022-01-28 21:03 ` kernel test robot
2022-01-28 22:08 ` Michel Lespinasse
2022-01-30 2:54 ` [mm] fa5331bae2: canonical_address#:#[##] kernel test robot
2022-01-30 5:08 ` Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 19/35] mm: enable speculative fault handling through do_anonymous_page() Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 20/35] mm: implement speculative handling in do_numa_page() Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 21/35] mm: enable speculative fault " Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 22/35] percpu-rwsem: enable percpu_sem destruction in atomic context Michel Lespinasse
[not found] ` <20220129121319.3593-1-hdanton@sina.com>
2022-01-31 18:04 ` Suren Baghdasaryan
[not found] ` <20220201020958.3720-1-hdanton@sina.com>
2022-02-07 19:31 ` Suren Baghdasaryan
[not found] ` <20220208002059.2670-1-hdanton@sina.com>
2022-02-08 1:31 ` Suren Baghdasaryan
2022-01-28 13:09 ` Michel Lespinasse [this message]
2022-07-27 7:34 ` [PATCH v2 23/35] mm: add mmu_notifier_lock Pavan Kondeti
2022-07-27 20:30 ` Suren Baghdasaryan
2022-01-28 13:09 ` [PATCH v2 24/35] mm: write lock mmu_notifier_lock when registering mmu notifiers Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 25/35] mm: add mmu_notifier_trylock() and mmu_notifier_unlock() Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 26/35] mm: implement speculative handling in wp_page_copy() Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 27/35] mm: implement and enable speculative fault handling in handle_pte_fault() Michel Lespinasse
2022-01-28 13:09 ` [PATCH v2 28/35] mm: disable speculative faults for single threaded user space Michel Lespinasse
2022-01-28 13:10 ` [PATCH v2 29/35] mm: disable rcu safe vma freeing " Michel Lespinasse
2022-01-28 13:10 ` [PATCH v2 30/35] mm: create new include/linux/vm_event.h header file Michel Lespinasse
2022-01-28 13:10 ` [PATCH v2 31/35] mm: anon spf statistics Michel Lespinasse
2022-01-28 13:10 ` [PATCH v2 32/35] arm64/mm: define ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT Michel Lespinasse
2022-01-28 13:10 ` [PATCH v2 33/35] arm64/mm: attempt speculative mm faults first Michel Lespinasse
2022-01-30 9:13 ` Mike Rapoport
2022-01-31 8:07 ` Michel Lespinasse
2022-02-01 8:58 ` Mike Rapoport
2022-02-07 17:39 ` Michel Lespinasse
2022-02-08 9:07 ` Mike Rapoport
2022-01-28 13:10 ` [PATCH v2 34/35] powerpc/mm: define ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT Michel Lespinasse
2022-01-28 13:10 ` [PATCH v2 35/35] powerpc/mm: attempt speculative mm faults first Michel Lespinasse
2022-01-31 9:56 ` [PATCH v2 00/35] Speculative page faults David Hildenbrand
2022-01-31 17:00 ` Suren Baghdasaryan
2022-02-01 1:14 ` Andrew Morton
2022-02-01 2:20 ` Matthew Wilcox
2022-02-07 17:39 ` Michel Lespinasse
2022-02-01 17:17 ` Sebastian Andrzej Siewior
2022-02-23 16:11 ` Mel Gorman
2022-03-08 5:37 ` Suren Baghdasaryan
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