This patch introduces two parameters cache_limit_ratio and cache_limit_mbytes. They are used to limit page cache amount.
Signed-off-by: Xishi Qiu <[email protected]> --- include/linux/swap.h | 10 ++++++++++ kernel/sysctl.c | 18 ++++++++++++++++++ mm/page_alloc.c | 39 +++++++++++++++++++++++++++++++++++++++ mm/vmscan.c | 17 +++++++++++++++++ 4 files changed, 84 insertions(+), 0 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 3507115..7e362d7 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -353,6 +353,16 @@ extern unsigned long shrink_all_memory(unsigned long nr_pages); extern int vm_swappiness; extern int remove_mapping(struct address_space *mapping, struct page *page); extern unsigned long vm_total_pages; +extern unsigned long vm_cache_limit_ratio; +extern unsigned long vm_cache_limit_ratio_min; +extern unsigned long vm_cache_limit_ratio_max; +extern unsigned long vm_cache_limit_mbytes; +extern unsigned long vm_cache_limit_mbytes_min; +extern unsigned long vm_cache_limit_mbytes_max; +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); #ifdef CONFIG_NUMA extern int zone_reclaim_mode; diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 74f5b58..9bb6f38 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1272,6 +1272,24 @@ static struct ctl_table vm_table[] = { .extra1 = &one, .extra2 = &four, }, + { + .procname = "cache_limit_ratio", + .data = &vm_cache_limit_ratio, + .maxlen = sizeof(vm_cache_limit_ratio), + .mode = 0644, + .proc_handler = cache_limit_ratio_sysctl_handler, + .extra1 = &vm_cache_limit_ratio_min, + .extra2 = &vm_cache_limit_ratio_max, + }, + { + .procname = "cache_limit_mbytes", + .data = &vm_cache_limit_mbytes, + .maxlen = sizeof(vm_cache_limit_mbytes), + .mode = 0644, + .proc_handler = cache_limit_mbytes_sysctl_handler, + .extra1 = &vm_cache_limit_mbytes_min, + .extra2 = &vm_cache_limit_mbytes_max, + }, #ifdef CONFIG_COMPACTION { .procname = "compact_memory", diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5dba293..a9cc034 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5790,6 +5790,45 @@ int min_free_kbytes_sysctl_handler(ctl_table *table, int write, return 0; } +int cache_limit_ratio_sysctl_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *length, loff_t *ppos) +{ + int ret; + + ret = proc_doulongvec_minmax(table, write, buffer, length, ppos); + if (ret) + return ret; + if (write) { + vm_cache_limit_mbytes = totalram_pages + * vm_cache_limit_ratio / 100 + * PAGE_SIZE / (1024 * 1024UL); + if (vm_cache_limit_ratio) + printk(KERN_WARNING "cache limit set to %ld%\n", + vm_cache_limit_ratio); + } + return 0; +} + +int cache_limit_mbytes_sysctl_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *length, loff_t *ppos) +{ + int ret; + + ret = proc_doulongvec_minmax(table, write, buffer, length, ppos); + if (ret) + return ret; + if (write) { + vm_cache_limit_ratio = (vm_cache_limit_mbytes + * ((1024 * 1024UL) / PAGE_SIZE) + + totalram_pages / 200) + * 100 / totalram_pages; + if (vm_cache_limit_mbytes) + printk(KERN_WARNING "cache limit set to %ldMB\n", + vm_cache_limit_mbytes); + } + 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 32c661d..37ea902 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -131,6 +131,12 @@ struct scan_control { */ int vm_swappiness = 60; unsigned long vm_total_pages; /* The total number of pages which the VM controls */ +unsigned long vm_cache_limit_ratio; +unsigned long vm_cache_limit_ratio_min; +unsigned long vm_cache_limit_ratio_max; +unsigned long vm_cache_limit_mbytes __read_mostly; +unsigned long vm_cache_limit_mbytes_min; +unsigned long vm_cache_limit_mbytes_max; static LIST_HEAD(shrinker_list); static DECLARE_RWSEM(shrinker_rwsem); @@ -3373,6 +3379,16 @@ unsigned long shrink_all_memory(unsigned long nr_to_reclaim) } #endif /* CONFIG_HIBERNATION */ +static void shrink_page_cache_init(void) +{ + vm_cache_limit_ratio = 0; + vm_cache_limit_ratio_min = 0; + vm_cache_limit_ratio_max = 100; + vm_cache_limit_mbytes = 0; + vm_cache_limit_mbytes_min = 0; + vm_cache_limit_mbytes_max = totalram_pages; +} + /* 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, @@ -3442,6 +3458,7 @@ static int __init kswapd_init(void) for_each_node_state(nid, N_MEMORY) kswapd_run(nid); hotcpu_notifier(cpu_callback, 0); + shrink_page_cache_init(); return 0; } -- 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/
