diff options
| author | Suren Baghdasaryan <surenb@google.com> | 2024-11-22 09:44:15 -0800 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2024-12-02 12:01:38 +0100 |
| commit | eb449bd96954b1c1e491d19066cfd2a010f0aa47 (patch) | |
| tree | 1fd8c4cad86a3f37e4989a70489051e3f34d1f21 /kernel/fork.c | |
| parent | 7528585290a1a1d4e0fb4b72261eb2d8c85de2d7 (diff) | |
mm: convert mm_lock_seq to a proper seqcount
Convert mm_lock_seq to be seqcount_t and change all mmap_write_lock
variants to increment it, in-line with the usual seqcount usage pattern.
This lets us check whether the mmap_lock is write-locked by checking
mm_lock_seq.sequence counter (odd=locked, even=unlocked). This will be
used when implementing mmap_lock speculation functions.
As a result vm_lock_seq is also change to be unsigned to match the type
of mm_lock_seq.sequence.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Link: https://lkml.kernel.org/r/20241122174416.1367052-2-surenb@google.com
Diffstat (limited to 'kernel/fork.c')
| -rw-r--r-- | kernel/fork.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 1450b461d196..8dc670fe90d4 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -448,7 +448,7 @@ static bool vma_lock_alloc(struct vm_area_struct *vma) return false; init_rwsem(&vma->vm_lock->lock); - vma->vm_lock_seq = -1; + vma->vm_lock_seq = UINT_MAX; return true; } @@ -1267,9 +1267,6 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, seqcount_init(&mm->write_protect_seq); mmap_init_lock(mm); INIT_LIST_HEAD(&mm->mmlist); -#ifdef CONFIG_PER_VMA_LOCK - mm->mm_lock_seq = 0; -#endif mm_pgtables_bytes_init(mm); mm->map_count = 0; mm->locked_vm = 0; |