diff options
| -rw-r--r-- | mm/vmpressure.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/mm/vmpressure.c b/mm/vmpressure.c index 75b7ffe9e7a3..f514dc40dab1 100644 --- a/mm/vmpressure.c +++ b/mm/vmpressure.c @@ -41,7 +41,7 @@ * TODO: Make the window size depend on machine size, as we do for vmstat * thresholds. Currently we set it to 512 pages (2MB for 4KB pages). */ -static const unsigned long vmpressure_win = SWAP_CLUSTER_MAX * 16; +static unsigned long vmpressure_win = SWAP_CLUSTER_MAX * 16; /* * These thresholds are used when we account memory pressure through @@ -290,6 +290,29 @@ void vmpressure_memcg(gfp_t gfp, struct mem_cgroup *memcg, schedule_work(&vmpr->work); } +void calculate_vmpressure_win(void) +{ + long x; + + x = global_page_state(NR_FILE_PAGES) - + global_page_state(NR_SHMEM) - + total_swapcache_pages() + + global_page_state(NR_FREE_PAGES); + if (x < 1) + x = 1; + /* + * For low (free + cached), vmpressure window should be + * small, and high for higher values of (free + cached). + * But it should not be linear as well. This ensures + * timely vmpressure notifications when system is under + * memory pressure, and optimal number of events when + * cached is high. The sqaure root function is empirically + * found to serve the purpose. + */ + x = int_sqrt(x); + vmpressure_win = x; +} + void vmpressure_global(gfp_t gfp, unsigned long scanned, unsigned long reclaimed) { @@ -304,6 +327,9 @@ void vmpressure_global(gfp_t gfp, unsigned long scanned, return; spin_lock(&vmpr->sr_lock); + if (!vmpr->scanned) + calculate_vmpressure_win(); + vmpr->scanned += scanned; vmpr->reclaimed += reclaimed; |