The patch titled
Subject: mm: zswap: modify zswap_stored_pages to be atomic_long_t.
has been added to the -mm mm-unstable branch. Its filename is
mm-zswap-modify-zswap_stored_pages-to-be-atomic_long_t.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zswap-modify-zswap_stored_pages-to-be-atomic_long_t.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Kanchana P Sridhar <kanchana.p.sridhar@xxxxxxxxx>
Subject: mm: zswap: modify zswap_stored_pages to be atomic_long_t.
Date: Mon, 30 Sep 2024 22:32:20 -0700
For zswap_store() to support large folios, we need to be able to do a
batch update of zswap_stored_pages upon successful store of all pages in
the folio. For this, we need to add folio_nr_pages(), which returns a
long, to zswap_stored_pages.
Link: https://lkml.kernel.org/r/20241001053222.6944-6-kanchana.p.sridhar@xxxxxxxxx
Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@xxxxxxxxx>
Acked-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Reviewed-by: Nhat Pham <nphamcs@xxxxxxxxx>
Cc: Chengming Zhou <chengming.zhou@xxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Cc: Usama Arif <usamaarif642@xxxxxxxxx>
Cc: Wajdi Feghali <wajdi.k.feghali@xxxxxxxxx>
Cc: "Zou, Nanhai" <nanhai.zou@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/meminfo.c | 2 +-
include/linux/zswap.h | 2 +-
mm/zswap.c | 19 +++++++++++++------
3 files changed, 15 insertions(+), 8 deletions(-)
--- a/fs/proc/meminfo.c~mm-zswap-modify-zswap_stored_pages-to-be-atomic_long_t
+++ a/fs/proc/meminfo.c
@@ -91,7 +91,7 @@ static int meminfo_proc_show(struct seq_
#ifdef CONFIG_ZSWAP
show_val_kb(m, "Zswap: ", zswap_total_pages());
seq_printf(m, "Zswapped: %8lu kB\n",
- (unsigned long)atomic_read(&zswap_stored_pages) <<
+ (unsigned long)atomic_long_read(&zswap_stored_pages) <<
(PAGE_SHIFT - 10));
#endif
show_val_kb(m, "Dirty: ",
--- a/include/linux/zswap.h~mm-zswap-modify-zswap_stored_pages-to-be-atomic_long_t
+++ a/include/linux/zswap.h
@@ -7,7 +7,7 @@
struct lruvec;
-extern atomic_t zswap_stored_pages;
+extern atomic_long_t zswap_stored_pages;
#ifdef CONFIG_ZSWAP
--- a/mm/zswap.c~mm-zswap-modify-zswap_stored_pages-to-be-atomic_long_t
+++ a/mm/zswap.c
@@ -43,7 +43,7 @@
* statistics
**********************************/
/* The number of compressed pages currently stored in zswap */
-atomic_t zswap_stored_pages = ATOMIC_INIT(0);
+atomic_long_t zswap_stored_pages = ATOMIC_INIT(0);
/*
* The statistics below are not protected from concurrent access for
@@ -802,7 +802,7 @@ static void zswap_entry_free(struct zswa
obj_cgroup_put(entry->objcg);
}
zswap_entry_cache_free(entry);
- atomic_dec(&zswap_stored_pages);
+ atomic_long_dec(&zswap_stored_pages);
}
/*********************************
@@ -1232,7 +1232,7 @@ static unsigned long zswap_shrinker_coun
nr_stored = memcg_page_state(memcg, MEMCG_ZSWAPPED);
} else {
nr_backing = zswap_total_pages();
- nr_stored = atomic_read(&zswap_stored_pages);
+ nr_stored = atomic_long_read(&zswap_stored_pages);
}
if (!nr_stored)
@@ -1501,7 +1501,7 @@ bool zswap_store(struct folio *folio)
}
/* update stats */
- atomic_inc(&zswap_stored_pages);
+ atomic_long_inc(&zswap_stored_pages);
count_vm_event(ZSWPOUT);
return true;
@@ -1650,6 +1650,13 @@ static int debugfs_get_total_size(void *
}
DEFINE_DEBUGFS_ATTRIBUTE(total_size_fops, debugfs_get_total_size, NULL, "%llu\n");
+static int debugfs_get_stored_pages(void *data, u64 *val)
+{
+ *val = atomic_long_read(&zswap_stored_pages);
+ return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(stored_pages_fops, debugfs_get_stored_pages, NULL, "%llu\n");
+
static int zswap_debugfs_init(void)
{
if (!debugfs_initialized())
@@ -1673,8 +1680,8 @@ static int zswap_debugfs_init(void)
zswap_debugfs_root, &zswap_written_back_pages);
debugfs_create_file("pool_total_size", 0444,
zswap_debugfs_root, NULL, &total_size_fops);
- debugfs_create_atomic_t("stored_pages", 0444,
- zswap_debugfs_root, &zswap_stored_pages);
+ debugfs_create_file("stored_pages", 0444,
+ zswap_debugfs_root, NULL, &stored_pages_fops);
return 0;
}
_
Patches currently in -mm which might be from kanchana.p.sridhar@xxxxxxxxx are
mm-define-obj_cgroup_get-if-config_memcg-is-not-defined.patch
mm-zswap-modify-zswap_compress-to-accept-a-page-instead-of-a-folio.patch
mm-zswap-rename-zswap_pool_get-to-zswap_pool_tryget.patch
mm-change-count_objcg_event-to-count_objcg_events-for-batch-event-updates.patch
mm-zswap-modify-zswap_stored_pages-to-be-atomic_long_t.patch
mm-zswap-support-large-folios-in-zswap_store.patch
mm-swap-count-successful-large-folio-zswap-stores-in-hugepage-zswpout-stats.patch
