diff options
| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2020-06-27 22:19:08 -0400 |
|---|---|---|
| committer | Matthew Wilcox (Oracle) <willy@infradead.org> | 2020-10-26 14:17:18 -0400 |
| commit | d7b0d86188965c9152eed8edc55027479bd722e9 (patch) | |
| tree | 8fcd7b4eb7ee1b13e4b493ea69994dd992d31881 /mm/migrate.c | |
| parent | b1cbfaa28309a0033d3d81a763cbd4911ef58b50 (diff) | |
mm: Use multi-index entries in the page cache
We currently store order-N THPs as 2^N consecutive entries. While this
consumes rather more memory than necessary, it also turns out to be buggy.
A writeback operation which starts in the middle of a dirty THP will not
notice as the dirty bit is only set on the head index. With multi-index
entries, the dirty bit will be found no matter where in the THP the
iteration starts.
This does end up simplifying the page cache slightly, although not as
much as I had hoped.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 8 |
1 files changed, 0 insertions, 8 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 262c91038c41..2dabb6e25e7c 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -460,14 +460,6 @@ int migrate_page_move_mapping(struct address_space *mapping, } xas_store(&xas, newpage); - if (PageTransHuge(page)) { - int i; - - for (i = 1; i < HPAGE_PMD_NR; i++) { - xas_next(&xas); - xas_store(&xas, newpage); - } - } /* * Drop cache reference from old page by unfreezing |