The patch titled Subject: mm/page_alloc: count CMA pages per zone and print them in /proc/zoneinfo has been added to the -mm tree. Its filename is mm-page_alloc-count-cma-pages-per-zone-and-print-them-in-proc-zoneinfo.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-count-cma-pages-per-zone-and-print-them-in-proc-zoneinfo.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-count-cma-pages-per-zone-and-print-them-in-proc-zoneinfo.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: David Hildenbrand <david@xxxxxxxxxx> Subject: mm/page_alloc: count CMA pages per zone and print them in /proc/zoneinfo Let's count the number of CMA pages per zone and print them in /proc/zoneinfo. Having access to the total number of CMA pages per zone is helpful for debugging purposes to know where exactly the CMA pages ended up, and to figure out how many pages of a zone might behave differently (e.g., like ZONE_MOVABLE) - even after some of these pages might already have been allocated. For now, we are only able to get the global nr+free cma pages from /proc/meminfo and the free cma pages per zone from /proc/zoneinfo. Note: Track/print that information even without CONFIG_CMA, similar to "nr_free_cma" in /proc/zoneinfo. This is different to /proc/meminfo - maybe we want to make that consistent in the future (however, changing /proc/zoneinfo output might uglify the code a bit). Link: https://lkml.kernel.org/r/20210127101813.6370-3-david@xxxxxxxxxx Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: "Peter Zijlstra (Intel)" <peterz@xxxxxxxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> Cc: Zi Yan <ziy@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mmzone.h | 4 ++++ mm/page_alloc.c | 1 + mm/vmstat.c | 6 ++++-- 3 files changed, 9 insertions(+), 2 deletions(-) --- a/include/linux/mmzone.h~mm-page_alloc-count-cma-pages-per-zone-and-print-them-in-proc-zoneinfo +++ a/include/linux/mmzone.h @@ -503,6 +503,9 @@ struct zone { * bootmem allocator): * managed_pages = present_pages - reserved_pages; * + * cma pages is present pages that are assigned for CMA use + * (MIGRATE_CMA). + * * So present_pages may be used by memory hotplug or memory power * management logic to figure out unmanaged pages by checking * (present_pages - managed_pages). And managed_pages should be used @@ -527,6 +530,7 @@ struct zone { atomic_long_t managed_pages; unsigned long spanned_pages; unsigned long present_pages; + unsigned long cma_pages; const char *name; --- a/mm/page_alloc.c~mm-page_alloc-count-cma-pages-per-zone-and-print-them-in-proc-zoneinfo +++ a/mm/page_alloc.c @@ -2168,6 +2168,7 @@ void __init init_cma_reserved_pageblock( } adjust_managed_page_count(page, pageblock_nr_pages); + page_zone(page)->cma_pages += pageblock_nr_pages; } #endif --- a/mm/vmstat.c~mm-page_alloc-count-cma-pages-per-zone-and-print-them-in-proc-zoneinfo +++ a/mm/vmstat.c @@ -1637,14 +1637,16 @@ static void zoneinfo_show_print(struct s "\n high %lu" "\n spanned %lu" "\n present %lu" - "\n managed %lu", + "\n managed %lu" + "\n cma %lu", zone_page_state(zone, NR_FREE_PAGES), min_wmark_pages(zone), low_wmark_pages(zone), high_wmark_pages(zone), zone->spanned_pages, zone->present_pages, - zone_managed_pages(zone)); + zone_managed_pages(zone), + zone->cma_pages); seq_printf(m, "\n protection: (%ld", _ Patches currently in -mm which might be from david@xxxxxxxxxx are video-fbdev-acornfb-remove-free_unused_pages.patch mm-simplify-free_highmem_page-and-free_reserved_page.patch mm-cma-expose-all-pages-to-the-buddy-if-activation-of-an-area-fails.patch mm-page_alloc-count-cma-pages-per-zone-and-print-them-in-proc-zoneinfo.patch mm-memory_hotplug-memhp_merge_resource-mhp_merge_resource.patch