On Mon, 8 Apr 2024 20:14:39 +0800 Zhaoyu Liu <liuzhaoyu.zackary@xxxxxxxxxxxxx> wrote: > Based on qemu arm64 - latest kernel + 100M memory + 1024M swapfile. > Create 1G anon mmap and set it to shared, and has two processes > randomly access the shared memory. When they are racing on swap cache, > on average, each "alloc_pages_mpol + swapcache_prepare + folio_put" > took about 1475 us. And what effect does this patch have upon the measured time? ANd upon overall runtime? > So skip page allocation if SWAP_HAS_CACHE was set, just > schedule_timeout_uninterruptible and continue to acquire page > via filemap_get_folio() from swap cache, to speedup > __read_swap_cache_async.
