The patch titled
Subject: mm/swapfile.c: offset is only used when there is more slots
has been added to the -mm tree. Its filename is
mm-swapfilec-offset-is-only-used-when-there-is-more-slots.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-swapfilec-offset-is-only-used-when-there-is-more-slots.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-swapfilec-offset-is-only-used-when-there-is-more-slots.patch
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------------------------------------------------------
From: Wei Yang <richard.weiyang@xxxxxxxxx>
Subject: mm/swapfile.c: offset is only used when there is more slots
scan_swap_map_slots() is used to iterate swap_map[] array for an available
swap entry. While after several optimizations, e.g. for ssd case, the
logic of this function is a little not easy to catch.
This patchset tries to clean up the logic a little:
* shows the ssd/non-ssd case is handled mutually exclusively
* remove some unnecessary goto for ssd case
This patch (of 3):
When si->cluster_nr is zero, function would reach done and return. The
increased offset would not be used any more. This means we can move the
offset increment into the if clause.
This brings a further code cleanup possibility.
Link: http://lkml.kernel.org/r/20200328060520.31449-1-richard.weiyang@xxxxxxxxx
Link: http://lkml.kernel.org/r/20200328060520.31449-2-richard.weiyang@xxxxxxxxx
Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/swapfile.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
--- a/mm/swapfile.c~mm-swapfilec-offset-is-only-used-when-there-is-more-slots
+++ a/mm/swapfile.c
@@ -874,11 +874,9 @@ checks:
else
goto done;
}
- /* non-ssd case */
- ++offset;
/* non-ssd case, still more slots in cluster? */
- if (si->cluster_nr && !si->swap_map[offset]) {
+ if (si->cluster_nr && !si->swap_map[++offset]) {
--si->cluster_nr;
goto checks;
}
_
Patches currently in -mm which might be from richard.weiyang@xxxxxxxxx are
mm-swapfilec-offset-is-only-used-when-there-is-more-slots.patch
mm-swapfilec-explicitly-show-ssd-non-ssd-is-handled-mutually-exclusive.patch
mm-swapfilec-remove-the-unnecessary-goto-for-ssd-case.patch
mm-page_allocc-bad_-is-not-necessary-when-pagehwpoison.patch
mm-page_allocc-bad_flags-is-not-necessary-for-bad_page.patch
mm-page_allocc-rename-free_pages_check_bad-to-check_free_page_bad.patch
mm-page_allocc-rename-free_pages_check-to-check_free_page.patch
mm-page_allocc-extract-check__page_bad-common-part-to-page_bad_reason.patch
mm-page_allocc-use-node_mask_none-in-build_zonelists.patch
mm-rename-gfpflags_to_migratetype-to-gfp_migratetype-for-same-convention.patch
mm-vmscanc-use-update_lru_size-in-update_lru_sizes.patch
