Re: why the count nr_file_pages is not equal to nr_inactive_file + nr_active_file ?

From: Xishi Qiu
Date: Mon May 16 2016 - 05:59:18 EST


On 2016/5/16 17:31, Michal Hocko wrote:

> On Fri 13-05-16 11:58:16, Xishi Qiu wrote:
>> I find the count nr_file_pages is not equal to nr_inactive_file + nr_active_file.
>> There are 8 cpus, 2 zones in my system.
>
> Because they count shmem pages as well and those are living on the anon
> lru list (see shmem_add_to_page_cache).

Hi Michal,

But the shmem seems very small.

nr_inactive_file 432444
nr_active_file 20659
nr_unevictable 2363
nr_shmem 128

nr_file_pages 462723

There is still 7129 pages difference.

root@hi3650:/ # cat /proc/vmstat
nr_free_pages 54192
nr_inactive_anon 39830
nr_active_anon 28794
nr_inactive_file 432444
nr_active_file 20659
nr_unevictable 2363
nr_mlock 0
nr_anon_pages 65249
nr_mapped 19742
nr_file_pages 462723
nr_dirty 20
nr_writeback 0
nr_slab_reclaimable 259333
nr_slab_unreclaimable 33463
nr_page_table_pages 3456
nr_kernel_stack 892
nr_unstable 0
nr_bounce 11
nr_vmscan_write 292032
nr_vmscan_immediate_reclaim 47204474
nr_writeback_temp 0
nr_isolated_anon 0
nr_isolated_file 0
nr_shmem 128
nr_dirtied 69574
nr_written 356299
nr_anon_transparent_hugepages 0
nr_free_cma 7519
nr_swapcache 41972
nr_dirty_threshold 6982
nr_dirty_background_threshold 99297