On 25.08.24 08:42, Lorenzo Stoakes wrote:
On Sun, Aug 25, 2024 at 01:06:40PM GMT, zhiguojiang wrote:
在 2024/8/25 0:26, Lorenzo Stoakes 写道:
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On Fri, Aug 23, 2024 at 11:02:06PM GMT, Zhiguo Jiang wrote:
After CoWed by do_wp_page, the vma established a new mapping relationship
with the CoWed folio instead of the non-CoWed folio. However, regarding
the situation where vma->anon_vma and the non-CoWed folio's anon_vma are
not same, the avc binding relationship between them will no longer be
needed, so it is issue for the avc binding relationship still existing
between them.
This patch will remove the avc binding relationship between vma and the
non-CoWed folio's anon_vma, which each has their own independent
anon_vma. It can also alleviates rmap overhead simultaneously.
Signed-off-by: Zhiguo Jiang <justinjiang@xxxxxxxx>
NACK (until fixed). This is broken (see below).
Hi Lorenzo Stoakes,
Thank you for your comments.
I'm not seeing any numbers to back anything up here as to why we want to
make changes to this incredibly sensitive code?
I added a debug trace log (as follows) in wp_page_copy() and observed
that a large number of these orphan avc-objects still exist. I believe
this will have a certain redundant overhead impact on anonymous folios'
rmap avcs, so I want to remove it, which is also the most essential
value of this patch.
Sorry nack to that idea unless you can provide actual _data_ to demonstrate
an overhead.
Agreed.
--
Cheers,
David / dhildenb
