From: Kairui Song <ryncsn@gmail.com>
To: linux-mm@kvack.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
Chris Li <chrisl@kernel.org>, Barry Song <v-songbaohua@oppo.com>,
Ryan Roberts <ryan.roberts@arm.com>,
Hugh Dickins <hughd@google.com>,
Yosry Ahmed <yosryahmed@google.com>,
"Huang, Ying" <ying.huang@intel.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Nhat Pham <nphamcs@gmail.com>,
linux-kernel@vger.kernel.org, Kairui Song <kasong@tencent.com>
Subject: [PATCH 05/13] mm, swap: clean up device availability check
Date: Wed, 23 Oct 2024 03:24:43 +0800 [thread overview]
Message-ID: <20241022192451.38138-6-ryncsn@gmail.com> (raw)
In-Reply-To: <20241022192451.38138-1-ryncsn@gmail.com>
From: Kairui Song <kasong@tencent.com>
Remove highest_bit and lowest_bit. After HDD allocation path is removed,
only purpose of these two fields is to judge if the device is full or
not, which can be done by checking inuse_pages instead.
Signed-off-by: Kairui Song <kasong@tencent.com>
---
fs/btrfs/inode.c | 1 -
fs/iomap/swapfile.c | 1 -
include/linux/swap.h | 2 --
mm/page_io.c | 1 -
mm/swapfile.c | 38 ++++++++------------------------------
5 files changed, 8 insertions(+), 35 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5618ca02934a..aba9c0d58998 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10023,7 +10023,6 @@ static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
*span = bsi.highest_ppage - bsi.lowest_ppage + 1;
sis->max = bsi.nr_pages;
sis->pages = bsi.nr_pages - 1;
- sis->highest_bit = bsi.nr_pages - 1;
return bsi.nr_extents;
}
#else
diff --git a/fs/iomap/swapfile.c b/fs/iomap/swapfile.c
index 5fc0ac36dee3..b90d0eda9e51 100644
--- a/fs/iomap/swapfile.c
+++ b/fs/iomap/swapfile.c
@@ -189,7 +189,6 @@ int iomap_swapfile_activate(struct swap_info_struct *sis,
*pagespan = 1 + isi.highest_ppage - isi.lowest_ppage;
sis->max = isi.nr_pages;
sis->pages = isi.nr_pages - 1;
- sis->highest_bit = isi.nr_pages - 1;
return isi.nr_extents;
}
EXPORT_SYMBOL_GPL(iomap_swapfile_activate);
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 3a71198a6957..c0d49dad7a4b 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -305,8 +305,6 @@ struct swap_info_struct {
struct list_head frag_clusters[SWAP_NR_ORDERS];
/* list of cluster that are fragmented or contented */
unsigned int frag_cluster_nr[SWAP_NR_ORDERS];
- unsigned int lowest_bit; /* index of first free in swap_map */
- unsigned int highest_bit; /* index of last free in swap_map */
unsigned int pages; /* total of usable pages of swap */
unsigned int inuse_pages; /* number of those currently in use */
struct percpu_cluster __percpu *percpu_cluster; /* per cpu's swap location */
diff --git a/mm/page_io.c b/mm/page_io.c
index a28d28b6b3ce..c8a25203bcf4 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -163,7 +163,6 @@ int generic_swapfile_activate(struct swap_info_struct *sis,
page_no = 1; /* force Empty message */
sis->max = page_no;
sis->pages = page_no - 1;
- sis->highest_bit = page_no - 1;
out:
return ret;
bad_bmap:
diff --git a/mm/swapfile.c b/mm/swapfile.c
index f8e70bb5f1d7..e620b41c3120 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -55,7 +55,7 @@ static bool swap_count_continued(struct swap_info_struct *, pgoff_t,
static void free_swap_count_continuations(struct swap_info_struct *);
static void swap_entry_range_free(struct swap_info_struct *si, swp_entry_t entry,
unsigned int nr_pages);
-static void swap_range_alloc(struct swap_info_struct *si, unsigned long offset,
+static void swap_range_alloc(struct swap_info_struct *si,
unsigned int nr_entries);
static bool folio_swapcache_freeable(struct folio *folio);
static struct swap_cluster_info *lock_cluster(struct swap_info_struct *si,
@@ -647,7 +647,7 @@ static void cluster_alloc_range(struct swap_info_struct *si, struct swap_cluster
}
memset(si->swap_map + start, usage, nr_pages);
- swap_range_alloc(si, start, nr_pages);
+ swap_range_alloc(si, nr_pages);
ci->count += nr_pages;
if (ci->count == SWAPFILE_CLUSTER) {
@@ -876,19 +876,11 @@ static void del_from_avail_list(struct swap_info_struct *si)
spin_unlock(&swap_avail_lock);
}
-static void swap_range_alloc(struct swap_info_struct *si, unsigned long offset,
+static void swap_range_alloc(struct swap_info_struct *si,
unsigned int nr_entries)
{
- unsigned int end = offset + nr_entries - 1;
-
- if (offset == si->lowest_bit)
- si->lowest_bit += nr_entries;
- if (end == si->highest_bit)
- WRITE_ONCE(si->highest_bit, si->highest_bit - nr_entries);
WRITE_ONCE(si->inuse_pages, si->inuse_pages + nr_entries);
if (si->inuse_pages == si->pages) {
- si->lowest_bit = si->max;
- si->highest_bit = 0;
del_from_avail_list(si);
if (vm_swap_full())
@@ -921,15 +913,8 @@ static void swap_range_free(struct swap_info_struct *si, unsigned long offset,
for (i = 0; i < nr_entries; i++)
clear_bit(offset + i, si->zeromap);
- if (offset < si->lowest_bit)
- si->lowest_bit = offset;
- if (end > si->highest_bit) {
- bool was_full = !si->highest_bit;
-
- WRITE_ONCE(si->highest_bit, end);
- if (was_full && (si->flags & SWP_WRITEOK))
- add_to_avail_list(si);
- }
+ if (si->inuse_pages == si->pages)
+ add_to_avail_list(si);
if (si->flags & SWP_BLKDEV)
swap_slot_free_notify =
si->bdev->bd_disk->fops->swap_slot_free_notify;
@@ -1035,15 +1020,12 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_order)
plist_requeue(&si->avail_lists[node], &swap_avail_heads[node]);
spin_unlock(&swap_avail_lock);
spin_lock(&si->lock);
- if (!si->highest_bit || !(si->flags & SWP_WRITEOK)) {
+ if ((si->inuse_pages == si->pages) || !(si->flags & SWP_WRITEOK)) {
spin_lock(&swap_avail_lock);
if (plist_node_empty(&si->avail_lists[node])) {
spin_unlock(&si->lock);
goto nextsi;
}
- WARN(!si->highest_bit,
- "swap_info %d in list but !highest_bit\n",
- si->type);
WARN(!(si->flags & SWP_WRITEOK),
"swap_info %d in list but !SWP_WRITEOK\n",
si->type);
@@ -2425,8 +2407,8 @@ static void _enable_swap_info(struct swap_info_struct *si)
*/
plist_add(&si->list, &swap_active_head);
- /* add to available list iff swap device is not full */
- if (si->highest_bit)
+ /* add to available list if swap device is not full */
+ if (si->inuse_pages < si->pages)
add_to_avail_list(si);
}
@@ -2590,7 +2572,6 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
drain_mmlist();
/* wait for anyone still in scan_swap_map_slots */
- p->highest_bit = 0; /* cuts scans short */
while (p->flags >= SWP_SCANNING) {
spin_unlock(&p->lock);
spin_unlock(&swap_lock);
@@ -2925,8 +2906,6 @@ static unsigned long read_swap_header(struct swap_info_struct *si,
return 0;
}
- si->lowest_bit = 1;
-
maxpages = swapfile_maximum_size;
last_page = swap_header->info.last_page;
if (!last_page) {
@@ -2943,7 +2922,6 @@ static unsigned long read_swap_header(struct swap_info_struct *si,
if ((unsigned int)maxpages == 0)
maxpages = UINT_MAX;
}
- si->highest_bit = maxpages - 1;
if (!maxpages)
return 0;
--
2.47.0
next prev parent reply other threads:[~2024-10-22 19:30 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-22 19:24 [PATCH 00/13] mm, swap: rework of swap allocator locks Kairui Song
2024-10-22 19:24 ` [PATCH 01/13] mm, swap: minor clean up for swap entry allocation Kairui Song
2024-10-22 19:24 ` [PATCH 02/13] mm, swap: fold swap_info_get_cont in the only caller Kairui Song
2024-10-22 19:24 ` [PATCH 03/13] mm, swap: remove old allocation path for HDD Kairui Song
2024-10-22 19:24 ` [PATCH 04/13] mm, swap: use cluster lock " Kairui Song
2024-10-22 19:24 ` Kairui Song [this message]
2024-10-22 19:24 ` [PATCH 06/13] mm, swap: clean up plist removal and adding Kairui Song
2024-10-22 19:24 ` [PATCH 07/13] mm, swap: hold a reference of si during scan and clean up flags Kairui Song
2024-10-22 19:24 ` [PATCH 08/13] mm, swap: use an enum to define all cluster flags and wrap flags changes Kairui Song
2024-10-22 19:24 ` [PATCH 09/13] mm, swap: reduce contention on device lock Kairui Song
2024-10-22 19:24 ` [PATCH 10/13] mm, swap: simplify percpu cluster updating Kairui Song
2024-10-22 19:24 ` [PATCH 11/13] mm, swap: introduce a helper for retrieving cluster from offset Kairui Song
2024-10-22 19:24 ` [PATCH 12/13] mm, swap: use a global swap cluster for non-rotation device Kairui Song
2024-10-22 19:37 ` [PATCH 13/13] mm, swap_slots: remove slot cache for freeing path Kairui Song
2024-10-23 2:24 ` [PATCH 00/13] mm, swap: rework of swap allocator locks Huang, Ying
2024-10-23 18:01 ` Kairui Song
2024-10-24 3:04 ` Huang, Ying
2024-10-24 3:51 ` Kairui Song
2024-10-23 10:27 ` Andrew Morton
2024-10-23 17:56 ` Kairui Song
2024-10-23 17:59 ` Yosry Ahmed
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