Add a new function shrink_page_cache(), it will call do_try_to_free_pages() to reclaim the page cache.
Signed-off-by: Xishi Qiu <[email protected]> --- include/linux/swap.h | 2 ++ mm/page_alloc.c | 12 ++++++++++++ mm/vmscan.c | 24 ++++++++++++++++++++++++ 3 files changed, 38 insertions(+), 0 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 7e362d7..dcbe1a3 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -363,6 +363,8 @@ extern int cache_limit_ratio_sysctl_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos); extern int cache_limit_mbytes_sysctl_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos); +extern unsigned long page_cache_over_limit(void); +extern void shrink_page_cache(gfp_t mask); #ifdef CONFIG_NUMA extern int zone_reclaim_mode; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a9cc034..00707ef 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5829,6 +5829,18 @@ int cache_limit_mbytes_sysctl_handler(struct ctl_table *table, int write, return 0; } +unsigned long page_cache_over_limit(void) +{ + unsigned long lru_file, limit; + + limit = vm_cache_limit_mbytes * ((1024 * 1024UL) / PAGE_SIZE); + lru_file = global_page_state(NR_ACTIVE_FILE) + + global_page_state(NR_INACTIVE_FILE); + if (lru_file > limit) + return lru_file - limit; + return 0; +} + #ifdef CONFIG_NUMA int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos) diff --git a/mm/vmscan.c b/mm/vmscan.c index 37ea902..ad01ff4 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3389,6 +3389,30 @@ static void shrink_page_cache_init(void) vm_cache_limit_mbytes_max = totalram_pages; } +static unsigned long __shrink_page_cache(gfp_t mask) +{ + struct scan_control sc = { + .gfp_mask = (mask = memalloc_noio_flags(mask)), + .may_writepage = !laptop_mode, + .nr_to_reclaim = SWAP_CLUSTER_MAX, + .may_unmap = 1, + .may_swap = 1, + .order = 0, + .priority = DEF_PRIORITY, + .target_mem_cgroup = NULL, + .nodemask = NULL, + }; + struct zonelist *zonelist = node_zonelist(numa_node_id(), mask); + + return do_try_to_free_pages(zonelist, &sc); +} + +void shrink_page_cache(gfp_t mask) +{ + /* We reclaim the highmem zone too, it is useful for 32bit arch */ + __shrink_page_cache(mask | __GFP_HIGHMEM); +} + /* It's optimal to keep kswapds on the same CPUs as their memory, but not required for correctness. So if the last cpu in a node goes away, we get changed to run anywhere: as the first one comes back, -- 1.6.0.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
