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| author | Liam R. Howlett <Liam.Howlett@oracle.com> | 2023-06-01 03:54:02 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-06-20 01:19:28 +0200 |
| commit | 65ac132027a884c411b8f9f96d240ba2dde34dec (patch) | |
| tree | f92d17b52dd61c61ca0678003c3715426f436fd1 /kernel/pid_sysctl.h | |
| parent | mm/folio: replace set_compound_order with folio_set_order (diff) | |
| download | linux-65ac132027a884c411b8f9f96d240ba2dde34dec.tar.xz linux-65ac132027a884c411b8f9f96d240ba2dde34dec.zip | |
userfaultfd: fix regression in userfaultfd_unmap_prep()
Android reported a performance regression in the userfaultfd unmap path.
A closer inspection on the userfaultfd_unmap_prep() change showed that a
second tree walk would be necessary in the reworked code.
Fix the regression by passing each VMA that will be unmapped through to
the userfaultfd_unmap_prep() function as they are added to the unmap list,
instead of re-walking the tree for the VMA.
Link: https://lkml.kernel.org/r/20230601015402.2819343-1-Liam.Howlett@oracle.com
Fixes: 69dbe6daf104 ("userfaultfd: use maple tree iterator to iterate VMAs")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel/pid_sysctl.h')
0 files changed, 0 insertions, 0 deletions