Re: [PATCHv7 03/14] mm: Report unaccepted memory in meminfo

David Hildenbrand
2022-07-26T14:33:24Z

On 14.06.22 14:02, Kirill A. Shutemov wrote:
> Track amount of unaccepted memory and report it in /proc/meminfo and in
> node meminfo.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> ---
> drivers/base/node.c | 7 +++++++
> fs/proc/meminfo.c | 5 +++++
> include/linux/mmzone.h | 1 +
> mm/page_alloc.c | 9 ++++++++-
> mm/vmstat.c | 1 +
> 5 files changed, 22 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/node.c b/drivers/base/node.c
> index 0ac6376ef7a1..fc7cf4d91eb6 100644
> --- a/drivers/base/node.c
> +++ b/drivers/base/node.c
> @@ -446,6 +446,9 @@ static ssize_t node_read_meminfo(struct device *dev,
> "Node %d ShmemPmdMapped: %8lu kB\n"
> "Node %d FileHugePages: %8lu kB\n"
> "Node %d FilePmdMapped: %8lu kB\n"
> +#endif
> +#ifdef CONFIG_UNACCEPTED_MEMORY
> + "Node %d UnacceptedPages: %8lu kB\n"

Nit: I'd just call that "Unaccepted", as the unit is kB.

> #endif
> ,
> nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
> @@ -474,6 +477,10 @@ static ssize_t node_read_meminfo(struct device *dev,
> nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)),
> nid, K(node_page_state(pgdat, NR_FILE_THPS)),
> nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED))
> +#endif
> +#ifdef CONFIG_UNACCEPTED_MEMORY
> + ,
> + nid, K(node_page_state(pgdat, NR_UNACCEPTED))
> #endif
> );
> len += hugetlb_report_node_meminfo(buf, len, nid);
> diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
> index 6e89f0e2fd20..796544e50365 100644
> --- a/fs/proc/meminfo.c
> +++ b/fs/proc/meminfo.c
> @@ -153,6 +153,11 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
> global_zone_page_state(NR_FREE_CMA_PAGES));
> #endif
>
> +#ifdef CONFIG_UNACCEPTED_MEMORY
> + show_val_kb(m, "UnacceptedPages:",
> + global_node_page_state(NR_UNACCEPTED));

Dito.

> +#endif
> +
> hugetlb_report_meminfo(m);
>
> arch_report_meminfo(m);
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index aab70355d64f..aa08cd7eaaf5 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -212,6 +212,7 @@ enum node_stat_item {
> NR_FOLL_PIN_ACQUIRED, /* via: pin_user_page(), gup flag: FOLL_PIN */
> NR_FOLL_PIN_RELEASED, /* pages returned via unpin_user_page() */
> NR_KERNEL_STACK_KB, /* measured in KiB */
> + NR_UNACCEPTED,

Do we want to ifdef that as well? (and in all other cases below)

> #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
> NR_KERNEL_SCS_KB, /* measured in KiB */
> #endif
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 279c2746aaa8..6316d695a567 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1012,6 +1012,7 @@ static void accept_page(struct page *page, unsigned int order)
>
> accept_memory(start, start + (PAGE_SIZE << order));
> __ClearPageUnaccepted(page);
> + mod_node_page_state(page_pgdat(page), NR_UNACCEPTED, -(1 << order));
>
> /* Assert that there is no PageUnaccepted() on tail pages */
> if (IS_ENABLED(CONFIG_DEBUG_VM)) {
> @@ -1063,6 +1064,7 @@ static inline void __free_one_page(struct page *page,
> struct page *buddy;
> bool to_tail;
> bool page_needs_acceptance = false;
> + int nr_unaccepted = 0;
>
> VM_BUG_ON(!zone_is_initialized(zone));
> VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
> @@ -1076,6 +1078,7 @@ static inline void __free_one_page(struct page *page,
>
> if (PageUnaccepted(page)) {
> page_needs_acceptance = true;
> + nr_unaccepted += 1 << order;
> __ClearPageUnaccepted(page);
> }
>
> @@ -1117,6 +1120,7 @@ static inline void __free_one_page(struct page *page,
> /* Mark page unaccepted if any of merged pages were unaccepted */
> if (PageUnaccepted(buddy)) {
> page_needs_acceptance = true;
> + nr_unaccepted += 1 << order;
> __ClearPageUnaccepted(buddy);
> }
>
> @@ -1143,8 +1147,11 @@ static inline void __free_one_page(struct page *page,
> */
> if (!page_needs_acceptance && (fpi_flags & FPI_UNACCEPTED_SLOWPATH))
> page_needs_acceptance = page_contains_unaccepted(page, order);
> - if (page_needs_acceptance)
> + if (page_needs_acceptance) {
> __SetPageUnaccepted(page);
> + __mod_node_page_state(page_pgdat(page), NR_UNACCEPTED,
> + (1 << order) - nr_unaccepted);
> + }
>
> if (fpi_flags & FPI_TO_TAIL)
> to_tail = true;
> diff --git a/mm/vmstat.c b/mm/vmstat.c
> index 373d2730fcf2..4e12d22f1e04 100644
> --- a/mm/vmstat.c
> +++ b/mm/vmstat.c
> @@ -1236,6 +1236,7 @@ const char * const vmstat_text[] = {
> "nr_foll_pin_acquired",
> "nr_foll_pin_released",
> "nr_kernel_stack",
> + "nr_unaccepted",
> #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
> "nr_shadow_call_stack",
> #endif

LGTM

--
Thanks,

David / dhildenb