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authorLinus Torvalds <torvalds@linux-foundation.org>2024-07-21 17:15:46 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2024-07-21 17:15:46 -0700
commitfbc90c042cd1dc7258ebfebe6d226017e5b5ac8c (patch)
tree45513ac12ade12a80ca6b306722f201802b0a190 /mm/zswap.c
parent7846b618e0a4c3e08888099d1d4512722b39ca99 (diff)
parent30d77b7eef019fa4422980806e8b7cdc8674493e (diff)
downloadnet-fbc90c042cd1dc7258ebfebe6d226017e5b5ac8c.tar.gz
Merge tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton: - In the series "mm: Avoid possible overflows in dirty throttling" Jan Kara addresses a couple of issues in the writeback throttling code. These fixes are also targetted at -stable kernels. - Ryusuke Konishi's series "nilfs2: fix potential issues related to reserved inodes" does that. This should actually be in the mm-nonmm-stable tree, along with the many other nilfs2 patches. My bad. - More folio conversions from Kefeng Wang in the series "mm: convert to folio_alloc_mpol()" - Kemeng Shi has sent some cleanups to the writeback code in the series "Add helper functions to remove repeated code and improve readability of cgroup writeback" - Kairui Song has made the swap code a little smaller and a little faster in the series "mm/swap: clean up and optimize swap cache index". - In the series "mm/memory: cleanly support zeropage in vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David Hildenbrand has reworked the rather sketchy handling of the use of the zeropage in MAP_SHARED mappings. I don't see any runtime effects here - more a cleanup/understandability/maintainablity thing. - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of higher addresses, for aarch64. The (poorly named) series is "Restructure va_high_addr_switch". - The core TLB handling code gets some cleanups and possible slight optimizations in Bang Li's series "Add update_mmu_tlb_range() to simplify code". - Jane Chu has improved the handling of our fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the series "Enhance soft hwpoison handling and injection". - Jeff Johnson has sent a billion patches everywhere to add MODULE_DESCRIPTION() to everything. Some landed in this pull. - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has simplified migration's use of hardware-offload memory copying. - Yosry Ahmed performs more folio API conversions in his series "mm: zswap: trivial folio conversions". - In the series "large folios swap-in: handle refault cases first", Chuanhua Han inches us forward in the handling of large pages in the swap code. This is a cleanup and optimization, working toward the end objective of full support of large folio swapin/out. - In the series "mm,swap: cleanup VMA based swap readahead window calculation", Huang Ying has contributed some cleanups and a possible fixlet to his VMA based swap readahead code. - In the series "add mTHP support for anonymous shmem" Baolin Wang has taught anonymous shmem mappings to use multisize THP. By default this is a no-op - users must opt in vis sysfs controls. Dramatic improvements in pagefault latency are realized. - David Hildenbrand has some cleanups to our remaining use of page_mapcount() in the series "fs/proc: move page_mapcount() to fs/proc/internal.h". - David also has some highmem accounting cleanups in the series "mm/highmem: don't track highmem pages manually". - Build-time fixes and cleanups from John Hubbard in the series "cleanups, fixes, and progress towards avoiding "make headers"". - Cleanups and consolidation of the core pagemap handling from Barry Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers and utilize them". - Lance Yang's series "Reclaim lazyfree THP without splitting" has reduced the latency of the reclaim of pmd-mapped THPs under fairly common circumstances. A 10x speedup is seen in a microbenchmark. It does this by punting to aother CPU but I guess that's a win unless all CPUs are pegged. - hugetlb_cgroup cleanups from Xiu Jianfeng in the series "mm/hugetlb_cgroup: rework on cftypes". - Miaohe Lin's series "Some cleanups for memory-failure" does just that thing. - Someone other than SeongJae has developed a DAMON feature in Honggyu Kim's series "DAMON based tiered memory management for CXL memory". This adds DAMON features which may be used to help determine the efficiency of our placement of CXL/PCIe attached DRAM. - DAMON user API centralization and simplificatio work in SeongJae Park's series "mm/damon: introduce DAMON parameters online commit function". - In the series "mm: page_type, zsmalloc and page_mapcount_reset()" David Hildenbrand does some maintenance work on zsmalloc - partially modernizing its use of pageframe fields. - Kefeng Wang provides more folio conversions in the series "mm: remove page_maybe_dma_pinned() and page_mkclean()". - More cleanup from David Hildenbrand, this time in the series "mm/memory_hotplug: use PageOffline() instead of PageReserved() for !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline() pages" and permits the removal of some virtio-mem hacks. - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and __folio_add_anon_rmap()" is a cleanup to the anon folio handling in preparation for mTHP (multisize THP) swapin. - Kefeng Wang's series "mm: improve clear and copy user folio" implements more folio conversions, this time in the area of large folio userspace copying. - The series "Docs/mm/damon/maintaier-profile: document a mailing tool and community meetup series" tells people how to get better involved with other DAMON developers. From SeongJae Park. - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does that. - David Hildenbrand sends along more cleanups, this time against the migration code. The series is "mm/migrate: move NUMA hinting fault folio isolation + checks under PTL". - Jan Kara has found quite a lot of strangenesses and minor errors in the readahead code. He addresses this in the series "mm: Fix various readahead quirks". - SeongJae Park's series "selftests/damon: test DAMOS tried regions and {min,max}_nr_regions" adds features and addresses errors in DAMON's self testing code. - Gavin Shan has found a userspace-triggerable WARN in the pagecache code. The series "mm/filemap: Limit page cache size to that supported by xarray" addresses this. The series is marked cc:stable. - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations and cleanup" cleans up and slightly optimizes KSM. - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of code motion. The series (which also makes the memcg-v1 code Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put under config option" and "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1" - Dan Schatzberg's series "Add swappiness argument to memory.reclaim" adds an additional feature to this cgroup-v2 control file. - The series "Userspace controls soft-offline pages" from Jiaqi Yan permits userspace to stop the kernel's automatic treatment of excessive correctable memory errors. In order to permit userspace to monitor and handle this situation. - Kefeng Wang's series "mm: migrate: support poison recover from migrate folio" teaches the kernel to appropriately handle migration from poisoned source folios rather than simply panicing. - SeongJae Park's series "Docs/damon: minor fixups and improvements" does those things. - In the series "mm/zsmalloc: change back to per-size_class lock" Chengming Zhou improves zsmalloc's scalability and memory utilization. - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare refcount increments. So these paes can first be moved aside if they reside in the movable zone or a CMA block. - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps for much faster reading of vma information. The series is "query VMAs from /proc/<pid>/maps". - In the series "mm: introduce per-order mTHP split counters" Lance Yang improves the kernel's presentation of developer information related to multisize THP splitting. - Michael Ellerman has developed the series "Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64)". This permits userspace to use all available huge page sizes. - In the series "revert unconditional slab and page allocator fault injection calls" Vlastimil Babka removes a performance-affecting and not very useful feature from slab fault injection. * tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits) mm/mglru: fix ineffective protection calculation mm/zswap: fix a white space issue mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio mm/hugetlb: fix possible recursive locking detected warning mm/gup: clear the LRU flag of a page before adding to LRU batch mm/numa_balancing: teach mpol_to_str about the balancing mode mm: memcg1: convert charge move flags to unsigned long long alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting lib: reuse page_ext_data() to obtain codetag_ref lib: add missing newline character in the warning message mm/mglru: fix overshooting shrinker memory mm/mglru: fix div-by-zero in vmpressure_calc_level() mm/kmemleak: replace strncpy() with strscpy() mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB mm: ignore data-race in __swap_writepage hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr mm: shmem: rename mTHP shmem counters mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async() mm/migrate: putback split folios when numa hint migration fails ...
Diffstat (limited to 'mm/zswap.c')
-rw-r--r--mm/zswap.c126
1 files changed, 61 insertions, 65 deletions
diff --git a/mm/zswap.c b/mm/zswap.c
index a50e2986cd2fab..adeaf9c97fdef6 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -83,6 +83,7 @@ static bool zswap_pool_reached_full;
static int zswap_setup(void);
/* Enable/disable zswap */
+static DEFINE_STATIC_KEY_MAYBE(CONFIG_ZSWAP_DEFAULT_ON, zswap_ever_enabled);
static bool zswap_enabled = IS_ENABLED(CONFIG_ZSWAP_DEFAULT_ON);
static int zswap_enabled_param_set(const char *,
const struct kernel_param *);
@@ -123,19 +124,21 @@ static unsigned int zswap_accept_thr_percent = 90; /* of max pool size */
module_param_named(accept_threshold_percent, zswap_accept_thr_percent,
uint, 0644);
-/* Number of zpools in zswap_pool (empirically determined for scalability) */
-#define ZSWAP_NR_ZPOOLS 32
-
/* Enable/disable memory pressure-based shrinker. */
static bool zswap_shrinker_enabled = IS_ENABLED(
CONFIG_ZSWAP_SHRINKER_DEFAULT_ON);
module_param_named(shrinker_enabled, zswap_shrinker_enabled, bool, 0644);
-bool is_zswap_enabled(void)
+bool zswap_is_enabled(void)
{
return zswap_enabled;
}
+bool zswap_never_enabled(void)
+{
+ return !static_branch_maybe(CONFIG_ZSWAP_DEFAULT_ON, &zswap_ever_enabled);
+}
+
/*********************************
* data structures
**********************************/
@@ -156,7 +159,7 @@ struct crypto_acomp_ctx {
* needs to be verified that it's still valid in the tree.
*/
struct zswap_pool {
- struct zpool *zpools[ZSWAP_NR_ZPOOLS];
+ struct zpool *zpool;
struct crypto_acomp_ctx __percpu *acomp_ctx;
struct percpu_ref ref;
struct list_head list;
@@ -238,7 +241,7 @@ static inline struct xarray *swap_zswap_tree(swp_entry_t swp)
#define zswap_pool_debug(msg, p) \
pr_debug("%s pool %s/%s\n", msg, (p)->tfm_name, \
- zpool_get_type((p)->zpools[0]))
+ zpool_get_type((p)->zpool))
/*********************************
* pool functions
@@ -247,7 +250,6 @@ static void __zswap_pool_empty(struct percpu_ref *ref);
static struct zswap_pool *zswap_pool_create(char *type, char *compressor)
{
- int i;
struct zswap_pool *pool;
char name[38]; /* 'zswap' + 32 char (max) num + \0 */
gfp_t gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM;
@@ -268,18 +270,14 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor)
if (!pool)
return NULL;
- for (i = 0; i < ZSWAP_NR_ZPOOLS; i++) {
- /* unique name for each pool specifically required by zsmalloc */
- snprintf(name, 38, "zswap%x",
- atomic_inc_return(&zswap_pools_count));
-
- pool->zpools[i] = zpool_create_pool(type, name, gfp);
- if (!pool->zpools[i]) {
- pr_err("%s zpool not available\n", type);
- goto error;
- }
+ /* unique name for each pool specifically required by zsmalloc */
+ snprintf(name, 38, "zswap%x", atomic_inc_return(&zswap_pools_count));
+ pool->zpool = zpool_create_pool(type, name, gfp);
+ if (!pool->zpool) {
+ pr_err("%s zpool not available\n", type);
+ goto error;
}
- pr_debug("using %s zpool\n", zpool_get_type(pool->zpools[0]));
+ pr_debug("using %s zpool\n", zpool_get_type(pool->zpool));
strscpy(pool->tfm_name, compressor, sizeof(pool->tfm_name));
@@ -312,8 +310,8 @@ ref_fail:
error:
if (pool->acomp_ctx)
free_percpu(pool->acomp_ctx);
- while (i--)
- zpool_destroy_pool(pool->zpools[i]);
+ if (pool->zpool)
+ zpool_destroy_pool(pool->zpool);
kfree(pool);
return NULL;
}
@@ -362,15 +360,12 @@ static struct zswap_pool *__zswap_pool_create_fallback(void)
static void zswap_pool_destroy(struct zswap_pool *pool)
{
- int i;
-
zswap_pool_debug("destroying", pool);
cpuhp_state_remove_instance(CPUHP_MM_ZSWP_POOL_PREPARE, &pool->node);
free_percpu(pool->acomp_ctx);
- for (i = 0; i < ZSWAP_NR_ZPOOLS; i++)
- zpool_destroy_pool(pool->zpools[i]);
+ zpool_destroy_pool(pool->zpool);
kfree(pool);
}
@@ -465,8 +460,7 @@ static struct zswap_pool *zswap_pool_find_get(char *type, char *compressor)
list_for_each_entry_rcu(pool, &zswap_pools, list) {
if (strcmp(pool->tfm_name, compressor))
continue;
- /* all zpools share the same type */
- if (strcmp(zpool_get_type(pool->zpools[0]), type))
+ if (strcmp(zpool_get_type(pool->zpool), type))
continue;
/* if we can't get it, it's about to be destroyed */
if (!zswap_pool_get(pool))
@@ -493,12 +487,8 @@ unsigned long zswap_total_pages(void)
unsigned long total = 0;
rcu_read_lock();
- list_for_each_entry_rcu(pool, &zswap_pools, list) {
- int i;
-
- for (i = 0; i < ZSWAP_NR_ZPOOLS; i++)
- total += zpool_get_total_pages(pool->zpools[i]);
- }
+ list_for_each_entry_rcu(pool, &zswap_pools, list)
+ total += zpool_get_total_pages(pool->zpool);
rcu_read_unlock();
return total;
@@ -803,11 +793,6 @@ static void zswap_entry_cache_free(struct zswap_entry *entry)
kmem_cache_free(zswap_entry_cache, entry);
}
-static struct zpool *zswap_find_zpool(struct zswap_entry *entry)
-{
- return entry->pool->zpools[hash_ptr(entry, ilog2(ZSWAP_NR_ZPOOLS))];
-}
-
/*
* Carries out the common pattern of freeing and entry's zpool allocation,
* freeing the entry itself, and decrementing the number of stored pages.
@@ -818,7 +803,7 @@ static void zswap_entry_free(struct zswap_entry *entry)
atomic_dec(&zswap_same_filled_pages);
else {
zswap_lru_del(&zswap_list_lru, entry);
- zpool_free(zswap_find_zpool(entry), entry->handle);
+ zpool_free(entry->pool->zpool, entry->handle);
zswap_pool_put(entry->pool);
}
if (entry->objcg) {
@@ -917,7 +902,7 @@ static bool zswap_compress(struct folio *folio, struct zswap_entry *entry)
dst = acomp_ctx->buffer;
sg_init_table(&input, 1);
- sg_set_page(&input, &folio->page, PAGE_SIZE, 0);
+ sg_set_folio(&input, folio, PAGE_SIZE, 0);
/*
* We need PAGE_SIZE * 2 here since there maybe over-compression case,
@@ -944,7 +929,7 @@ static bool zswap_compress(struct folio *folio, struct zswap_entry *entry)
if (comp_ret)
goto unlock;
- zpool = zswap_find_zpool(entry);
+ zpool = entry->pool->zpool;
gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM;
if (zpool_malloc_support_movable(zpool))
gfp |= __GFP_HIGHMEM | __GFP_MOVABLE;
@@ -971,9 +956,9 @@ unlock:
return comp_ret == 0 && alloc_ret == 0;
}
-static void zswap_decompress(struct zswap_entry *entry, struct page *page)
+static void zswap_decompress(struct zswap_entry *entry, struct folio *folio)
{
- struct zpool *zpool = zswap_find_zpool(entry);
+ struct zpool *zpool = entry->pool->zpool;
struct scatterlist input, output;
struct crypto_acomp_ctx *acomp_ctx;
u8 *src;
@@ -1000,7 +985,7 @@ static void zswap_decompress(struct zswap_entry *entry, struct page *page)
sg_init_one(&input, src, entry->length);
sg_init_table(&output, 1);
- sg_set_page(&output, page, PAGE_SIZE, 0);
+ sg_set_folio(&output, folio, PAGE_SIZE, 0);
acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, PAGE_SIZE);
BUG_ON(crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait));
BUG_ON(acomp_ctx->req->dlen != PAGE_SIZE);
@@ -1073,7 +1058,7 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
return -ENOMEM;
}
- zswap_decompress(entry, &folio->page);
+ zswap_decompress(entry, folio);
count_vm_event(ZSWPWB);
if (entry->objcg)
@@ -1375,35 +1360,35 @@ resched:
**********************************/
static bool zswap_is_folio_same_filled(struct folio *folio, unsigned long *value)
{
- unsigned long *page;
+ unsigned long *data;
unsigned long val;
- unsigned int pos, last_pos = PAGE_SIZE / sizeof(*page) - 1;
+ unsigned int pos, last_pos = PAGE_SIZE / sizeof(*data) - 1;
bool ret = false;
- page = kmap_local_folio(folio, 0);
- val = page[0];
+ data = kmap_local_folio(folio, 0);
+ val = data[0];
- if (val != page[last_pos])
+ if (val != data[last_pos])
goto out;
for (pos = 1; pos < last_pos; pos++) {
- if (val != page[pos])
+ if (val != data[pos])
goto out;
}
*value = val;
ret = true;
out:
- kunmap_local(page);
+ kunmap_local(data);
return ret;
}
-static void zswap_fill_page(void *ptr, unsigned long value)
+static void zswap_fill_folio(struct folio *folio, unsigned long value)
{
- unsigned long *page;
+ unsigned long *data = kmap_local_folio(folio, 0);
- page = (unsigned long *)ptr;
- memset_l(page, value, PAGE_SIZE / sizeof(unsigned long));
+ memset_l(data, value, PAGE_SIZE / sizeof(unsigned long));
+ kunmap_local(data);
}
/*********************************
@@ -1525,7 +1510,7 @@ store_failed:
if (!entry->length)
atomic_dec(&zswap_same_filled_pages);
else {
- zpool_free(zswap_find_zpool(entry), entry->handle);
+ zpool_free(entry->pool->zpool, entry->handle);
put_pool:
zswap_pool_put(entry->pool);
}
@@ -1551,14 +1536,26 @@ bool zswap_load(struct folio *folio)
{
swp_entry_t swp = folio->swap;
pgoff_t offset = swp_offset(swp);
- struct page *page = &folio->page;
bool swapcache = folio_test_swapcache(folio);
struct xarray *tree = swap_zswap_tree(swp);
struct zswap_entry *entry;
- u8 *dst;
VM_WARN_ON_ONCE(!folio_test_locked(folio));
+ if (zswap_never_enabled())
+ return false;
+
+ /*
+ * Large folios should not be swapped in while zswap is being used, as
+ * they are not properly handled. Zswap does not properly load large
+ * folios, and a large folio may only be partially in zswap.
+ *
+ * Return true without marking the folio uptodate so that an IO error is
+ * emitted (e.g. do_swap_page() will sigbus).
+ */
+ if (WARN_ON_ONCE(folio_test_large(folio)))
+ return true;
+
/*
* When reading into the swapcache, invalidate our entry. The
* swapcache can be the authoritative owner of the page and
@@ -1580,12 +1577,9 @@ bool zswap_load(struct folio *folio)
return false;
if (entry->length)
- zswap_decompress(entry, page);
- else {
- dst = kmap_local_page(page);
- zswap_fill_page(dst, entry->value);
- kunmap_local(dst);
- }
+ zswap_decompress(entry, folio);
+ else
+ zswap_fill_folio(folio, entry->value);
count_vm_event(ZSWPIN);
if (entry->objcg)
@@ -1596,6 +1590,7 @@ bool zswap_load(struct folio *folio)
folio_mark_dirty(folio);
}
+ folio_mark_uptodate(folio);
return true;
}
@@ -1737,9 +1732,10 @@ static int zswap_setup(void)
pool = __zswap_pool_create_fallback();
if (pool) {
pr_info("loaded using pool %s/%s\n", pool->tfm_name,
- zpool_get_type(pool->zpools[0]));
+ zpool_get_type(pool->zpool));
list_add(&pool->list, &zswap_pools);
zswap_has_pool = true;
+ static_branch_enable(&zswap_ever_enabled);
} else {
pr_err("pool creation failed\n");
zswap_enabled = false;