From: Davidlohr Bueso <dave@stgolabs.net>
To: akpm@linux-foundation.org
Cc: hughd@google.com, riel@redhat.com, mgorman@suse.de,
peterz@infradead.org, mingo@kernel.org,
linux-kernel@vger.kernel.org, dbueso@suse.de, linux-mm@kvack.org,
Davidlohr Bueso <dave@stgolabs.net>
Subject: [PATCH 08/10] mm/mremap: share the i_mmap_rwsem
Date: Thu, 30 Oct 2014 12:34:15 -0700 [thread overview]
Message-ID: <1414697657-1678-9-git-send-email-dave@stgolabs.net> (raw)
In-Reply-To: <1414697657-1678-1-git-send-email-dave@stgolabs.net>
As per the comment in move_ptes(), we only require taking the
anon vma and i_mmap locks to ensure that rmap will always observe
either the old or new ptes, in the case of need_rmap_lock=true.
No modifications to the tree itself, thus share the i_mmap_rwsem.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@intel.linux.com>
---
mm/mremap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/mremap.c b/mm/mremap.c
index c929324..09bd644 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -119,7 +119,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
if (need_rmap_locks) {
if (vma->vm_file) {
mapping = vma->vm_file->f_mapping;
- i_mmap_lock_write(mapping);
+ i_mmap_lock_read(mapping);
}
if (vma->anon_vma) {
anon_vma = vma->anon_vma;
@@ -156,7 +156,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
if (anon_vma)
anon_vma_unlock_read(anon_vma);
if (mapping)
- i_mmap_unlock_write(mapping);
+ i_mmap_unlock_read(mapping);
}
#define LATENCY_LIMIT (64 * PAGE_SIZE)
--
1.8.4.5
next prev parent reply other threads:[~2014-10-30 19:34 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-30 19:34 [PATCH v2 -next 00/10] mm: improve usage of the i_mmap lock Davidlohr Bueso
2014-10-30 19:34 ` [PATCH 01/10] mm,fs: introduce helpers around the i_mmap_mutex Davidlohr Bueso
2014-10-30 19:34 ` [PATCH 02/10] mm: use new helper functions " Davidlohr Bueso
2014-10-30 19:34 ` [PATCH 03/10] mm: convert i_mmap_mutex to rwsem Davidlohr Bueso
2014-10-30 19:34 ` [PATCH 04/10] mm/rmap: share the i_mmap_rwsem Davidlohr Bueso
2014-10-30 19:34 ` [PATCH 05/10] uprobes: " Davidlohr Bueso
2014-10-30 19:34 ` [PATCH 06/10] mm/xip: " Davidlohr Bueso
2014-10-30 19:34 ` [PATCH 07/10] mm/memory-failure: " Davidlohr Bueso
2014-10-30 19:34 ` Davidlohr Bueso [this message]
2014-11-04 6:04 ` [PATCH 08/10] mm/mremap: " Hugh Dickins
2014-11-04 12:29 ` Kirill A. Shutemov
2014-10-30 19:34 ` [PATCH 09/10] mm/nommu: " Davidlohr Bueso
2014-10-30 19:34 ` [PATCH 10/10] mm/hugetlb: " Davidlohr Bueso
2014-11-04 6:35 ` Hugh Dickins
2014-11-05 0:59 ` Davidlohr Bueso
2014-11-05 16:04 ` Hugh Dickins
2014-11-10 16:22 ` Mel Gorman
2014-11-03 8:17 ` [PATCH v2 -next 00/10] mm: improve usage of the i_mmap lock Peter Zijlstra
2014-11-10 16:28 ` Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2014-10-24 22:06 [PATCH " Davidlohr Bueso
2014-10-24 22:06 ` [PATCH 08/10] mm/mremap: share the i_mmap_rwsem Davidlohr Bueso
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