The patch titled
Subject: mm/swapfile.c: open code cluster_alloc_swap()
has been added to the -mm mm-unstable branch. Its filename is
mm-swapfilec-open-code-cluster_alloc_swap.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-swapfilec-open-code-cluster_alloc_swap.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Baoquan He <bhe@xxxxxxxxxx>
Subject: mm/swapfile.c: open code cluster_alloc_swap()
Date: Wed, 5 Feb 2025 17:27:21 +0800
It's only called in scan_swap_map_slots().
And also remove the stale code comment in scan_swap_map_slots() because
it's not fit for the current cluster allocation mechanism.
Link: https://lkml.kernel.org/r/20250205092721.9395-13-bhe@xxxxxxxxxx
Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
Cc: Chis Li <chrisl@xxxxxxxxxx>
Cc: Kairui Song <ryncsn@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/swapfile.c | 38 ++++++++++----------------------------
1 file changed, 10 insertions(+), 28 deletions(-)
--- a/mm/swapfile.c~mm-swapfilec-open-code-cluster_alloc_swap
+++ a/mm/swapfile.c
@@ -1158,39 +1158,13 @@ static void swap_range_free(struct swap_
swap_usage_sub(si, nr_entries);
}
-static int cluster_alloc_swap(struct swap_info_struct *si,
- unsigned char usage, int nr,
- swp_entry_t slots[], int order)
-{
- int n_ret = 0;
-
- while (n_ret < nr) {
- unsigned long offset = cluster_alloc_swap_entry(si, order, usage);
-
- if (!offset)
- break;
- slots[n_ret++] = swp_entry(si->type, offset);
- }
-
- return n_ret;
-}
-
static int scan_swap_map_slots(struct swap_info_struct *si,
unsigned char usage, int nr,
swp_entry_t slots[], int order)
{
unsigned int nr_pages = 1 << order;
+ int n_ret = 0;
- /*
- * We try to cluster swap pages by allocating them sequentially
- * in swap. Once we've allocated SWAPFILE_CLUSTER pages this
- * way, however, we resort to first-free allocation, starting
- * a new cluster. This prevents us from scattering swap pages
- * all over the entire swap partition, so that we reduce
- * overall disk seek times between swap pages. -- sct
- * But we do now try to find an empty cluster. -Andrea
- * And we let swap pages go all over an SSD partition. Hugh
- */
if (order > 0) {
/*
* Should not even be attempting large allocations when huge
@@ -1210,7 +1184,15 @@ static int scan_swap_map_slots(struct sw
return 0;
}
- return cluster_alloc_swap(si, usage, nr, slots, order);
+ while (n_ret < nr) {
+ unsigned long offset = cluster_alloc_swap_entry(si, order, usage);
+
+ if (!offset)
+ break;
+ slots[n_ret++] = swp_entry(si->type, offset);
+ }
+
+ return n_ret;
}
static bool get_swap_device_info(struct swap_info_struct *si)
_
Patches currently in -mm which might be from bhe@xxxxxxxxxx are
mm-swap_statec-fix-the-obsolete-code-comment.patch
mm-swap_statec-optimize-the-code-in-clear_shadow_from_swap_cache.patch
mm-swap-remove-swap_flag_prio_shift.patch
mm-swap-skip-scanning-cluster-range-if-its-empty-cluster.patch
mm-swap-rename-swap_is_has_cache-to-swap_only_has_cache.patch
mm-swapfilec-update-the-code-comment-above-swap_count_continued.patch
mm-swapfilec-optimize-code-in-setup_clusters.patch
mm-swap_statec-remove-the-meaningless-code-comment.patch
mm-swapfilec-remove-the-unneeded-checking.patch
mm-swap-rename-swap_swapcount-to-swap_entry_swapped.patch
mm-swapfilec-remove-the-incorrect-code-comment.patch
mm-swapfilec-open-code-cluster_alloc_swap.patch
