Re: [PATCH 19/27] mm: Move vmscan writes and file write accounting to the node

From: Michal Hocko
Date: Wed Jun 22 2016 - 10:40:46 EST

On Tue 21-06-16 15:15:58, Mel Gorman wrote:
> As reclaim is now node-based, it follows that page write activity
> due to page reclaim should also be accounted for on the node. For
> consistency, also account page writes and page dirtying on a per-node
> basis.
>
> After this patch, there are a few remaining zone counters that may
> appear strange but are fine. NUMA stats are still per-zone as this is a
> user-space interface that tools consume. NR_MLOCK, NR_SLAB_*, NR_PAGETABLE,
> NR_KERNEL_STACK and NR_BOUNCE are all allocations that potentially pin
> low memory and cannot trivially be reclaimed on demand. This information
> is still useful for debugging a page allocation failure warning.

As I've said in other patch. I think we will need to provide
/proc/nodeinfo to fill the gap.

> Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
> Acked-by: Vlastimil Babka <vbabka@xxxxxxx>

Acked-by: Michal Hocko <mhocko@xxxxxxxx>

> ---
> include/linux/mmzone.h | 8 ++++----
> include/trace/events/writeback.h | 4 ++--
> mm/page-writeback.c | 6 +++---
> mm/vmscan.c | 4 ++--
> mm/vmstat.c | 8 ++++----
> 5 files changed, 15 insertions(+), 15 deletions(-)
>
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index 9924b46e3a13..9c59b8540cb7 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -121,10 +121,6 @@ enum zone_stat_item {
> NR_KERNEL_STACK,
> /* Second 128 byte cacheline */
> NR_BOUNCE,
> - NR_VMSCAN_WRITE,
> - NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */
> - NR_DIRTIED, /* page dirtyings since bootup */
> - NR_WRITTEN, /* page writings since bootup */
> #if IS_ENABLED(CONFIG_ZSMALLOC)
> NR_ZSPAGES, /* allocated in zsmalloc */
> #endif
> @@ -162,6 +158,10 @@ enum node_stat_item {
> NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
> NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */
> NR_UNSTABLE_NFS, /* NFS unstable pages */
> + NR_VMSCAN_WRITE,
> + NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */
> + NR_DIRTIED, /* page dirtyings since bootup */
> + NR_WRITTEN, /* page writings since bootup */
> NR_VM_NODE_STAT_ITEMS
> };
>
> diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
> index c581d9c04ca5..a1002cfede1d 100644
> --- a/include/trace/events/writeback.h
> +++ b/include/trace/events/writeback.h
> @@ -415,8 +415,8 @@ TRACE_EVENT(global_dirty_state,
> __entry->nr_dirty = global_node_page_state(NR_FILE_DIRTY);
> __entry->nr_writeback = global_node_page_state(NR_WRITEBACK);
> __entry->nr_unstable = global_node_page_state(NR_UNSTABLE_NFS);
> - __entry->nr_dirtied = global_page_state(NR_DIRTIED);
> - __entry->nr_written = global_page_state(NR_WRITTEN);
> + __entry->nr_dirtied = global_node_page_state(NR_DIRTIED);
> + __entry->nr_written = global_node_page_state(NR_WRITTEN);
> __entry->background_thresh = background_thresh;
> __entry->dirty_thresh = dirty_thresh;
> __entry->dirty_limit = global_wb_domain.dirty_limit;
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index aa9fa1eb8b80..95f38a59f9a0 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -2433,7 +2433,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping)
>
> mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_DIRTY);
> __inc_node_page_state(page, NR_FILE_DIRTY);
> - __inc_zone_page_state(page, NR_DIRTIED);
> + __inc_node_page_state(page, NR_DIRTIED);
> __inc_wb_stat(wb, WB_RECLAIMABLE);
> __inc_wb_stat(wb, WB_DIRTIED);
> task_io_account_write(PAGE_SIZE);
> @@ -2521,7 +2521,7 @@ void account_page_redirty(struct page *page)
>
> wb = unlocked_inode_to_wb_begin(inode, &locked);
> current->nr_dirtied--;
> - dec_zone_page_state(page, NR_DIRTIED);
> + dec_node_page_state(page, NR_DIRTIED);
> dec_wb_stat(wb, WB_DIRTIED);
> unlocked_inode_to_wb_end(inode, locked);
> }
> @@ -2750,7 +2750,7 @@ int test_clear_page_writeback(struct page *page)
> if (ret) {
> mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_WRITEBACK);
> dec_node_page_state(page, NR_WRITEBACK);
> - inc_zone_page_state(page, NR_WRITTEN);
> + inc_node_page_state(page, NR_WRITTEN);
> }
> unlock_page_memcg(page);
> return ret;
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 4501a9ab1d3f..1f7c1262c0a3 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -612,7 +612,7 @@ static pageout_t pageout(struct page *page, struct address_space *mapping,
> ClearPageReclaim(page);
> }
> trace_mm_vmscan_writepage(page);
> - inc_zone_page_state(page, NR_VMSCAN_WRITE);
> + inc_node_page_state(page, NR_VMSCAN_WRITE);
> return PAGE_SUCCESS;
> }
>
> @@ -1111,7 +1111,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
> * except we already have the page isolated
> * and know it's dirty
> */
> - inc_zone_page_state(page, NR_VMSCAN_IMMEDIATE);
> + inc_node_page_state(page, NR_VMSCAN_IMMEDIATE);
> SetPageReclaim(page);
>
> goto keep_locked;
> diff --git a/mm/vmstat.c b/mm/vmstat.c
> index 32c499251174..b58ceb8c872c 100644
> --- a/mm/vmstat.c
> +++ b/mm/vmstat.c
> @@ -929,10 +929,6 @@ const char * const vmstat_text[] = {
> "nr_page_table_pages",
> "nr_kernel_stack",
> "nr_bounce",
> - "nr_vmscan_write",
> - "nr_vmscan_immediate_reclaim",
> - "nr_dirtied",
> - "nr_written",
> #if IS_ENABLED(CONFIG_ZSMALLOC)
> "nr_zspages",
> #endif
> @@ -967,6 +963,10 @@ const char * const vmstat_text[] = {
> "nr_writeback_temp",
> "nr_shmem",
> "nr_unstable",
> + "nr_vmscan_write",
> + "nr_vmscan_immediate_reclaim",
> + "nr_dirtied",
> + "nr_written",
>
> /* enum writeback_stat_item counters */
> "nr_dirty_threshold",
> --
> 2.6.4
>
> --
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--
Michal Hocko
SUSE Labs