The patch titled
Subject: mm: optimise madvise WILLNEED
has been added to the -mm tree. Its filename is
mm-optimise-madvise-willneed.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-optimise-madvise-willneed.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-optimise-madvise-willneed.patch
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm: optimise madvise WILLNEED
Instead of calling find_get_entry() for every page index, use an XArray
iterator to skip over NULL entries, and avoid calling get_page(),
because we only want the swap entries.
Link: https://lkml.kernel.org/r/20200910183318.20139-4-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Huang Ying <ying.huang@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
Cc: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: William Kucharski <william.kucharski@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/madvise.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)
--- a/mm/madvise.c~mm-optimise-madvise-willneed
+++ a/mm/madvise.c
@@ -224,25 +224,28 @@ static void force_shm_swapin_readahead(s
unsigned long start, unsigned long end,
struct address_space *mapping)
{
- pgoff_t index;
+ XA_STATE(xas, &mapping->i_pages, linear_page_index(vma, start));
+ pgoff_t end_index = end / PAGE_SIZE;
struct page *page;
- swp_entry_t swap;
- for (; start < end; start += PAGE_SIZE) {
- index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+ rcu_read_lock();
+ xas_for_each(&xas, page, end_index) {
+ swp_entry_t swap;
- page = find_get_entry(mapping, index);
- if (!xa_is_value(page)) {
- if (page)
- put_page(page);
+ if (!xa_is_value(page))
continue;
- }
+ rcu_read_unlock();
+
swap = radix_to_swp_entry(page);
page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE,
NULL, 0, false);
if (page)
put_page(page);
+
+ rcu_read_lock();
+ xas_reset(&xas);
}
+ rcu_read_unlock();
lru_add_drain(); /* Push any new pages onto the LRU now */
}
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-debug-do-not-dereference-i_ino-blindly.patch
mm-factor-find_get_incore_page-out-of-mincore_page.patch
mm-use-find_get_incore_page-in-memcontrol.patch
mm-optimise-madvise-willneed.patch
proc-optimise-smaps-for-shmem-entries.patch
i915-use-find_lock_page-instead-of-find_lock_entry.patch
mm-convert-find_get_entry-to-return-the-head-page.patch
mm-shmem-return-head-page-from-find_lock_entry.patch
mm-add-find_lock_head.patch
mm-account-pmd-tables-like-pte-tables.patch
mm-move-pagedoublemap-bit.patch
mm-simplify-pagedoublemap-with-pf_second-policy.patch
xarray-add-xa_get_order.patch
xarray-add-xas_split.patch
xarray-add-xas_split-fix-2.patch
mm-filemap-fix-storing-to-a-thp-shadow-entry.patch
mm-filemap-fix-page-cache-removal-for-arbitrary-sized-thps.patch
mm-memory-remove-page-fault-assumption-of-compound-page-size.patch
mm-page_owner-change-split_page_owner-to-take-a-count.patch
mm-huge_memory-fix-page_trans_huge_mapcount-assumption-of-thp-size.patch
mm-huge_memory-fix-can_split_huge_page-assumption-of-thp-size.patch
mm-rmap-fix-assumptions-of-thp-size.patch
mm-truncate-fix-truncation-for-pages-of-arbitrary-size.patch
mm-page-writeback-support-tail-pages-in-wait_for_stable_page.patch
mm-vmscan-allow-arbitrary-sized-pages-to-be-paged-out.patch
mm-readahead-add-define_readahead.patch
mm-readahead-make-page_cache_ra_unbounded-take-a-readahead_control.patch
mm-readahead-make-do_page_cache_ra-take-a-readahead_control.patch
mm-readahead-add-page_cache_sync_ra-and-page_cache_async_ra.patch
harden-autofs-ioctl-table.patch
