diff options
| author | Ryan Roberts <ryan.roberts@arm.com> | 2024-04-08 21:39:41 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-04-26 06:56:37 +0300 |
| commit | a62fb92ac12ed39df4930dca599a3b427552882a (patch) | |
| tree | c0f9ffe693552fb8c89aae858db0186976579e50 /include/linux/swap.h | |
| parent | d7d0d389ff90644546ffcb8e15ea3ccaf6138958 (diff) | |
| download | linux-a62fb92ac12ed39df4930dca599a3b427552882a.tar.xz | |
mm: swap: free_swap_and_cache_nr() as batched free_swap_and_cache()
Now that we no longer have a convenient flag in the cluster to determine
if a folio is large, free_swap_and_cache() will take a reference and lock
a large folio much more often, which could lead to contention and (e.g.)
failure to split large folios, etc.
Let's solve that problem by batch freeing swap and cache with a new
function, free_swap_and_cache_nr(), to free a contiguous range of swap
entries together. This allows us to first drop a reference to each swap
slot before we try to release the cache folio. This means we only try to
release the folio once, only taking the reference and lock once - much
better than the previous 512 times for the 2M THP case.
Contiguous swap entries are gathered in zap_pte_range() and
madvise_free_pte_range() in a similar way to how present ptes are already
gathered in zap_pte_range().
While we are at it, let's simplify by converting the return type of both
functions to void. The return value was used only by zap_pte_range() to
print a bad pte, and was ignored by everyone else, so the extra reporting
wasn't exactly guaranteed. We will still get the warning with most of the
information from get_swap_device(). With the batch version, we wouldn't
know which pte was bad anyway so could print the wrong one.
[ryan.roberts@arm.com: fix a build warning on parisc]
Link: https://lkml.kernel.org/r/20240409111840.3173122-1-ryan.roberts@arm.com
Link: https://lkml.kernel.org/r/20240408183946.2991168-3-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Gao Xiang <xiang@kernel.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux/swap.h')
| -rw-r--r-- | include/linux/swap.h | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index a803de0ac24f..2d8f2b950ddf 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -468,7 +468,7 @@ extern int swap_duplicate(swp_entry_t); extern int swapcache_prepare(swp_entry_t); extern void swap_free(swp_entry_t); extern void swapcache_free_entries(swp_entry_t *entries, int n); -extern int free_swap_and_cache(swp_entry_t); +extern void free_swap_and_cache_nr(swp_entry_t entry, int nr); int swap_type_of(dev_t device, sector_t offset); int find_first_swap(dev_t *device); extern unsigned int count_swap_pages(int, int); @@ -517,8 +517,9 @@ static inline void put_swap_device(struct swap_info_struct *si) #define free_pages_and_swap_cache(pages, nr) \ release_pages((pages), (nr)); -/* used to sanity check ptes in zap_pte_range when CONFIG_SWAP=0 */ -#define free_swap_and_cache(e) is_pfn_swap_entry(e) +static inline void free_swap_and_cache_nr(swp_entry_t entry, int nr) +{ +} static inline void free_swap_cache(struct folio *folio) { @@ -586,6 +587,11 @@ static inline int add_swap_extent(struct swap_info_struct *sis, } #endif /* CONFIG_SWAP */ +static inline void free_swap_and_cache(swp_entry_t entry) +{ + free_swap_and_cache_nr(entry, 1); +} + #ifdef CONFIG_MEMCG static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) { |