diff options
| author | Huang Ying <ying.huang@intel.com> | 2018-08-22 06:52:29 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-22 19:52:44 +0200 |
| commit | c2343d2761f86ae1b857f78c7cdb9f51e5fa1641 (patch) | |
| tree | 120ef158f9ec2f707de488e1ec4f9a04fa14efe9 | |
| parent | mm/swapfile.c: add __swap_entry_free_locked() (diff) | |
| download | linux-c2343d2761f86ae1b857f78c7cdb9f51e5fa1641.tar.xz linux-c2343d2761f86ae1b857f78c7cdb9f51e5fa1641.zip | |
mm/swapfile.c: put_swap_page: share more between huge/normal code path
In this patch, locking related code is shared between huge/normal code
path in put_swap_page() to reduce code duplication. The `free_entries == 0`
case is merged into the more general `free_entries != SWAPFILE_CLUSTER`
case, because the new locking method makes it easy.
The added lines is same as the removed lines. But the code size is
increased when CONFIG_TRANSPARENT_HUGEPAGE=n.
text data bss dec hex filename
base: 24123 2004 340 26467 6763 mm/swapfile.o
unified: 24485 2004 340 26829 68cd mm/swapfile.o
Dig on step deeper with `size -A mm/swapfile.o` for base and unified
kernel and compare the result, yields,
-.text 17723 0
+.text 17835 0
-.orc_unwind_ip 1380 0
+.orc_unwind_ip 1480 0
-.orc_unwind 2070 0
+.orc_unwind 2220 0
-Total 26686
+Total 27048
The total difference is the same. The text segment difference is much
smaller: 112. More difference comes from the ORC unwinder segments:
(1480 + 2220) - (1380 + 2070) = 250. If the frame pointer unwinder is
used, this costs nothing.
Link: http://lkml.kernel.org/r/20180720071845.17920-9-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/swapfile.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index d44b2d60a66a..d954b71c4f9c 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1223,8 +1223,8 @@ void put_swap_page(struct page *page, swp_entry_t entry) if (!si) return; + ci = lock_cluster_or_swap_info(si, offset); if (size == SWAPFILE_CLUSTER) { - ci = lock_cluster(si, offset); VM_BUG_ON(!cluster_is_huge(ci)); map = si->swap_map + offset; for (i = 0; i < SWAPFILE_CLUSTER; i++) { @@ -1233,13 +1233,9 @@ void put_swap_page(struct page *page, swp_entry_t entry) if (val == SWAP_HAS_CACHE) free_entries++; } - if (!free_entries) { - for (i = 0; i < SWAPFILE_CLUSTER; i++) - map[i] &= ~SWAP_HAS_CACHE; - } cluster_clear_huge(ci); - unlock_cluster(ci); if (free_entries == SWAPFILE_CLUSTER) { + unlock_cluster_or_swap_info(si, ci); spin_lock(&si->lock); ci = lock_cluster(si, offset); memset(map, 0, SWAPFILE_CLUSTER); @@ -1250,12 +1246,16 @@ void put_swap_page(struct page *page, swp_entry_t entry) return; } } - if (size == 1 || free_entries) { - for (i = 0; i < size; i++, entry.val++) { - if (!__swap_entry_free(si, entry, SWAP_HAS_CACHE)) - free_swap_slot(entry); + for (i = 0; i < size; i++, entry.val++) { + if (!__swap_entry_free_locked(si, offset + i, SWAP_HAS_CACHE)) { + unlock_cluster_or_swap_info(si, ci); + free_swap_slot(entry); + if (i == size - 1) + return; + lock_cluster_or_swap_info(si, offset); } } + unlock_cluster_or_swap_info(si, ci); } #ifdef CONFIG_THP_SWAP |