[patch 040/118] mm/rmap: correct some obsolete comments of anon_vma
From: Andrew Morton <akpm@linux-foundation.org>
Date: 2021-02-26 01:17:56
Also in:
mm-commits
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: mm/rmap: correct some obsolete comments of anon_vma
commit 2b575eb64f7a ("mm: convert anon_vma->lock to a mutex") changed
spinlock used to serialize access to vma list to mutex. And further, the
commit 5a505085f043 ("mm/rmap: Convert the struct anon_vma::mutex to an
rwsem") converted the mutex to an rwsem for solving scalability problem.
So replace spinlock with rwsem to make comment uptodate.
Link: https://lkml.kernel.org/r/20210123072459.25903-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/rmap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/mm/rmap.c~mm-rmap-correct-some-obsolete-comments-of-anon_vma
+++ a/mm/rmap.c@@ -168,7 +168,7 @@ static void anon_vma_chain_link(struct v * * Anon-vma allocations are very subtle, because we may have * optimistically looked up an anon_vma in page_lock_anon_vma_read() - * and that may actually touch the spinlock even in the newly + * and that may actually touch the rwsem even in the newly * allocated vma (it depends on RCU to make sure that the * anon_vma isn't actually destroyed). *
@@ -359,7 +359,7 @@ int anon_vma_fork(struct vm_area_struct goto out_error_free_anon_vma; /* - * The root anon_vma's spinlock is the lock actually used when we + * The root anon_vma's rwsem is the lock actually used when we * lock any of the anon_vmas in this anon_vma tree. */ anon_vma->root = pvma->anon_vma->root;
_