The patch titled
Subject: mm, swap, get_swap_pages: use entry_size instead of cluster in parameter
has been added to the -mm tree. Its filename is
swap-get_swap_pages-use-entry_size-instead-of-cluster-in-parameter.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/swap-get_swap_pages-use-entry_size-instead-of-cluster-in-parameter.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/swap-get_swap_pages-use-entry_size-instead-of-cluster-in-parameter.patch
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------------------------------------------------------
From: Huang Ying <ying.huang@xxxxxxxxx>
Subject: mm, swap, get_swap_pages: use entry_size instead of cluster in parameter
As suggested by Matthew Wilcox, it is better to use "int entry_size"
instead of "bool cluster" as parameter to specify whether to operate for
huge or normal swap entries. Because this improve the flexibility to
support other swap entry size. And Dave Hansen thinks that this improves
code readability too.
So in this patch, the "bool cluster" parameter of get_swap_pages() is
replaced by "int entry_size".
And nr_swap_entries() trick is used to reduce the binary size when
!CONFIG_TRANSPARENT_HUGE_PAGE.
text data bss dec hex filename
base 24215 2028 340 26583 67d7 mm/swapfile.o
head 24123 2004 340 26467 6763 mm/swapfile.o
Link: http://lkml.kernel.org/r/20180720071845.17920-7-ying.huang@xxxxxxxxx
Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Shaohua Li <shli@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/swap.h | 2 +-
mm/swap_slots.c | 8 ++++----
mm/swapfile.c | 16 ++++++++--------
3 files changed, 13 insertions(+), 13 deletions(-)
diff -puN include/linux/swap.h~swap-get_swap_pages-use-entry_size-instead-of-cluster-in-parameter include/linux/swap.h
--- a/include/linux/swap.h~swap-get_swap_pages-use-entry_size-instead-of-cluster-in-parameter
+++ a/include/linux/swap.h
@@ -447,7 +447,7 @@ extern void si_swapinfo(struct sysinfo *
extern swp_entry_t get_swap_page(struct page *page);
extern void put_swap_page(struct page *page, swp_entry_t entry);
extern swp_entry_t get_swap_page_of_type(int);
-extern int get_swap_pages(int n, bool cluster, swp_entry_t swp_entries[]);
+extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size);
extern int add_swap_count_continuation(swp_entry_t, gfp_t);
extern void swap_shmem_alloc(swp_entry_t);
extern int swap_duplicate(swp_entry_t);
diff -puN mm/swapfile.c~swap-get_swap_pages-use-entry_size-instead-of-cluster-in-parameter mm/swapfile.c
--- a/mm/swapfile.c~swap-get_swap_pages-use-entry_size-instead-of-cluster-in-parameter
+++ a/mm/swapfile.c
@@ -940,18 +940,18 @@ static unsigned long scan_swap_map(struc
}
-int get_swap_pages(int n_goal, bool cluster, swp_entry_t swp_entries[])
+int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
{
- unsigned long nr_pages = cluster ? SWAPFILE_CLUSTER : 1;
+ unsigned long size = swap_entry_size(entry_size);
struct swap_info_struct *si, *next;
long avail_pgs;
int n_ret = 0;
int node;
/* Only single cluster request supported */
- WARN_ON_ONCE(n_goal > 1 && cluster);
+ WARN_ON_ONCE(n_goal > 1 && size == SWAPFILE_CLUSTER);
- avail_pgs = atomic_long_read(&nr_swap_pages) / nr_pages;
+ avail_pgs = atomic_long_read(&nr_swap_pages) / size;
if (avail_pgs <= 0)
goto noswap;
@@ -961,7 +961,7 @@ int get_swap_pages(int n_goal, bool clus
if (n_goal > avail_pgs)
n_goal = avail_pgs;
- atomic_long_sub(n_goal * nr_pages, &nr_swap_pages);
+ atomic_long_sub(n_goal * size, &nr_swap_pages);
spin_lock(&swap_avail_lock);
@@ -988,14 +988,14 @@ start_over:
spin_unlock(&si->lock);
goto nextsi;
}
- if (cluster) {
+ if (size == SWAPFILE_CLUSTER) {
if (!(si->flags & SWP_FILE))
n_ret = swap_alloc_cluster(si, swp_entries);
} else
n_ret = scan_swap_map_slots(si, SWAP_HAS_CACHE,
n_goal, swp_entries);
spin_unlock(&si->lock);
- if (n_ret || cluster)
+ if (n_ret || size == SWAPFILE_CLUSTER)
goto check_out;
pr_debug("scan_swap_map of si %d failed to find offset\n",
si->type);
@@ -1021,7 +1021,7 @@ nextsi:
check_out:
if (n_ret < n_goal)
- atomic_long_add((long)(n_goal - n_ret) * nr_pages,
+ atomic_long_add((long)(n_goal - n_ret) * size,
&nr_swap_pages);
noswap:
return n_ret;
diff -puN mm/swap_slots.c~swap-get_swap_pages-use-entry_size-instead-of-cluster-in-parameter mm/swap_slots.c
--- a/mm/swap_slots.c~swap-get_swap_pages-use-entry_size-instead-of-cluster-in-parameter
+++ a/mm/swap_slots.c
@@ -269,8 +269,8 @@ static int refill_swap_slots_cache(struc
cache->cur = 0;
if (swap_slot_cache_active)
- cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE, false,
- cache->slots);
+ cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE,
+ cache->slots, 1);
return cache->nr;
}
@@ -316,7 +316,7 @@ swp_entry_t get_swap_page(struct page *p
if (PageTransHuge(page)) {
if (IS_ENABLED(CONFIG_THP_SWAP))
- get_swap_pages(1, true, &entry);
+ get_swap_pages(1, &entry, HPAGE_PMD_NR);
goto out;
}
@@ -350,7 +350,7 @@ repeat:
goto out;
}
- get_swap_pages(1, false, &entry);
+ get_swap_pages(1, &entry, 1);
out:
if (mem_cgroup_try_charge_swap(page, entry)) {
put_swap_page(page, entry);
_
Patches currently in -mm which might be from ying.huang@xxxxxxxxx are
mm-clear_huge_page-move-order-algorithm-into-a-separate-function.patch
mm-huge-page-copy-target-sub-page-last-when-copy-huge-page.patch
mm-hugetlbfs-rename-address-to-haddr-in-hugetlb_cow.patch
mm-hugetlbfs-pass-fault-address-to-cow-handler.patch
mm-swap-make-config_thp_swap-depends-on-config_swap.patch
swap-add-comments-to-lock_cluster_or_swap_info.patch
mm-swapfilec-replace-some-ifdef-with-is_enabled.patch
swap-use-swap_count-in-swap_page_trans_huge_swapped.patch
swap-unify-normal-huge-code-path-in-swap_page_trans_huge_swapped.patch
swap-unify-normal-huge-code-path-in-put_swap_page.patch
swap-get_swap_pages-use-entry_size-instead-of-cluster-in-parameter.patch
swap-add-__swap_entry_free_locked.patch
swap-put_swap_page-share-more-between-huge-normal-code-path.patch
mm-swap-fix-race-between-swapoff-and-some-swap-operations.patch
mm-swap-fix-race-between-swapoff-and-some-swap-operations-v6.patch
mm-fix-race-between-swapoff-and-mincore.patch
--
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