From: Huang Ying <ying.huang@xxxxxxxxx> Subject: memcg, THP, swap: make mem_cgroup_swapout() support THP This patch makes mem_cgroup_swapout() works for the transparent huge page (THP). Which will move the memory cgroup charge from memory to swap for a THP. This will be used for the THP swap support. Where a THP may be swapped out as a whole to a set of (HPAGE_PMD_NR) continuous swap slots on the swap device. Link: http://lkml.kernel.org/r/20170724051840.2309-11-ying.huang@xxxxxxxxx Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: "Kirill A . Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Ross Zwisler <ross.zwisler@xxxxxxxxx> [for brd.c, zram_drv.c, pmem.c] Cc: Shaohua Li <shli@xxxxxxxxxx> Cc: Vishal L Verma <vishal.l.verma@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff -puN mm/memcontrol.c~memcg-thp-swap-make-mem_cgroup_swapout-support-thp mm/memcontrol.c --- a/mm/memcontrol.c~memcg-thp-swap-make-mem_cgroup_swapout-support-thp +++ a/mm/memcontrol.c @@ -4654,8 +4654,8 @@ static enum mc_target_type get_mctgt_typ #ifdef CONFIG_TRANSPARENT_HUGEPAGE /* - * We don't consider swapping or file mapped pages because THP does not - * support them for now. + * We don't consider PMD mapped swapping or file mapped pages because THP does + * not support them for now. * Caller should make sure that pmd_trans_huge(pmd) is true. */ static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, @@ -5913,6 +5913,7 @@ static struct mem_cgroup *mem_cgroup_id_ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) { struct mem_cgroup *memcg, *swap_memcg; + unsigned int nr_entries; unsigned short oldid; VM_BUG_ON_PAGE(PageLRU(page), page); @@ -5933,19 +5934,24 @@ void mem_cgroup_swapout(struct page *pag * ancestor for the swap instead and transfer the memory+swap charge. */ swap_memcg = mem_cgroup_id_get_online(memcg); - oldid = swap_cgroup_record(entry, mem_cgroup_id(swap_memcg), 1); + nr_entries = hpage_nr_pages(page); + /* Get references for the tail pages, too */ + if (nr_entries > 1) + mem_cgroup_id_get_many(swap_memcg, nr_entries - 1); + oldid = swap_cgroup_record(entry, mem_cgroup_id(swap_memcg), + nr_entries); VM_BUG_ON_PAGE(oldid, page); - mem_cgroup_swap_statistics(swap_memcg, 1); + mem_cgroup_swap_statistics(swap_memcg, nr_entries); page->mem_cgroup = NULL; if (!mem_cgroup_is_root(memcg)) - page_counter_uncharge(&memcg->memory, 1); + page_counter_uncharge(&memcg->memory, nr_entries); if (memcg != swap_memcg) { if (!mem_cgroup_is_root(swap_memcg)) - page_counter_charge(&swap_memcg->memsw, 1); - page_counter_uncharge(&memcg->memsw, 1); + page_counter_charge(&swap_memcg->memsw, nr_entries); + page_counter_uncharge(&memcg->memsw, nr_entries); } /* @@ -5955,7 +5961,8 @@ void mem_cgroup_swapout(struct page *pag * only synchronisation we have for udpating the per-CPU variables. */ VM_BUG_ON(!irqs_disabled()); - mem_cgroup_charge_statistics(memcg, page, false, -1); + mem_cgroup_charge_statistics(memcg, page, PageTransHuge(page), + -nr_entries); memcg_check_events(memcg, page); if (!mem_cgroup_is_root(memcg)) _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
