The patch titled Subject: mm: memcontrol: convert NR_FILE_PMDMAPPED account to pages has been added to the -mm tree. Its filename is mm-memcontrol-convert-nr_file_pmdmapped-account-to-pages.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-memcontrol-convert-nr_file_pmdmapped-account-to-pages.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-memcontrol-convert-nr_file_pmdmapped-account-to-pages.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: Muchun Song <songmuchun@xxxxxxxxxxxxx> Subject: mm: memcontrol: convert NR_FILE_PMDMAPPED account to pages Currently we use struct per_cpu_nodestat to cache the vmstat counters, which leads to inaccurate statistics expecially THP vmstat counters. In the systems with hundreads of processors it can be GBs of memory. For example, for a 96 CPUs system, the threshold is the maximum number of 125. And the per cpu counters can cache 23.4375 GB in total. The THP page is already a form of batched addition (it will add 512 worth of memory in one go) so skipping the batching seems like sensible. Although every THP stats update overflows the per-cpu counter, resorting to atomic global updates. But it can make the statistics more accuracy for the THP vmstat counters. So we convert the NR_FILE_PMDMAPPED account to pages. This patch is consistent with 8f182270dfec ("mm/swap.c: flush lru pvecs on compound page arrival"). Doing this also can make the unit of vmstat counters more unified. Finally, the unit of the vmstat counters are pages, kB and bytes. The B/KB suffix can tell us that the unit is bytes or kB. The rest which is without suffix are pages. Link: https://lkml.kernel.org/r/20201217034356.4708-7-songmuchun@xxxxxxxxxxxxx Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx> Cc: Feng Tang <feng.tang@xxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: NeilBrown <neilb@xxxxxxx> Cc: Pankaj Gupta <pankaj.gupta@xxxxxxxxxxxxxxx> Cc: Rafael. J. Wysocki <rafael@xxxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Roman Gushchin <guro@xxxxxx> Cc: Sami Tolvanen <samitolvanen@xxxxxxxxxx> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/base/node.c | 3 +-- fs/proc/meminfo.c | 2 +- include/linux/mmzone.h | 3 ++- mm/rmap.c | 6 ++++-- 4 files changed, 8 insertions(+), 6 deletions(-) --- a/drivers/base/node.c~mm-memcontrol-convert-nr_file_pmdmapped-account-to-pages +++ a/drivers/base/node.c @@ -465,8 +465,7 @@ static ssize_t node_read_meminfo(struct nid, K(node_page_state(pgdat, NR_SHMEM_THPS)), 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) * - HPAGE_PMD_NR) + nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED)) #endif ); len += hugetlb_report_node_meminfo(buf, len, nid); --- a/fs/proc/meminfo.c~mm-memcontrol-convert-nr_file_pmdmapped-account-to-pages +++ a/fs/proc/meminfo.c @@ -137,7 +137,7 @@ static int meminfo_proc_show(struct seq_ show_val_kb(m, "FileHugePages: ", global_node_page_state(NR_FILE_THPS)); show_val_kb(m, "FilePmdMapped: ", - global_node_page_state(NR_FILE_PMDMAPPED) * HPAGE_PMD_NR); + global_node_page_state(NR_FILE_PMDMAPPED)); #endif #ifdef CONFIG_CMA --- a/include/linux/mmzone.h~mm-memcontrol-convert-nr_file_pmdmapped-account-to-pages +++ a/include/linux/mmzone.h @@ -219,7 +219,8 @@ static __always_inline bool vmstat_item_ return item == NR_ANON_THPS || item == NR_FILE_THPS || item == NR_SHMEM_THPS || - item == NR_SHMEM_PMDMAPPED; + item == NR_SHMEM_PMDMAPPED || + item == NR_FILE_PMDMAPPED; } /* --- a/mm/rmap.c~mm-memcontrol-convert-nr_file_pmdmapped-account-to-pages +++ a/mm/rmap.c @@ -1223,7 +1223,8 @@ void page_add_file_rmap(struct page *pag __mod_lruvec_page_state(page, NR_SHMEM_PMDMAPPED, nr_pages); else - __inc_node_page_state(page, NR_FILE_PMDMAPPED); + __mod_lruvec_page_state(page, NR_FILE_PMDMAPPED, + nr_pages); } else { if (PageTransCompound(page) && page_mapping(page)) { VM_WARN_ON_ONCE(!PageLocked(page)); @@ -1267,7 +1268,8 @@ static void page_remove_file_rmap(struct __mod_lruvec_page_state(page, NR_SHMEM_PMDMAPPED, -nr_pages); else - __dec_node_page_state(page, NR_FILE_PMDMAPPED); + __mod_lruvec_page_state(page, NR_FILE_PMDMAPPED, + -nr_pages); } else { if (!atomic_add_negative(-1, &page->_mapcount)) return; _ Patches currently in -mm which might be from songmuchun@xxxxxxxxxxxxx are mm-memcontrol-fix-nr_anon_thps-accounting-in-charge-moving.patch mm-memcontrol-convert-nr_anon_thps-account-to-pages.patch mm-memcontrol-convert-nr_file_thps-account-to-pages.patch mm-memcontrol-convert-nr_shmem_thps-account-to-pages.patch mm-memcontrol-convert-nr_shmem_pmdmapped-account-to-pages.patch mm-memcontrol-convert-nr_file_pmdmapped-account-to-pages.patch mm-memcontrol-make-the-slab-calculation-consistent.patch