The patch titled Subject: mm: memcontrol: move obj_cgroup_uncharge_pages() out of css_set_lock has been added to the -mm tree. Its filename is mm-memcontrol-move-obj_cgroup_uncharge_pages-out-of-css_set_lock.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-memcontrol-move-obj_cgroup_uncharge_pages-out-of-css_set_lock.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-memcontrol-move-obj_cgroup_uncharge_pages-out-of-css_set_lock.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: move obj_cgroup_uncharge_pages() out of css_set_lock The css_set_lock is used to guard the list of inherited objcgs. So there is no need to uncharge kernel memory under css_set_lock. Just move it out of the lock. Link: https://lkml.kernel.org/r/20210417043538.9793-8-songmuchun@xxxxxxxxxxxxx Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> Acked-by: Roman Gushchin <guro@xxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Cc: Xiongchun Duan <duanxiongchun@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/memcontrol.c~mm-memcontrol-move-obj_cgroup_uncharge_pages-out-of-css_set_lock +++ a/mm/memcontrol.c @@ -289,9 +289,10 @@ static void obj_cgroup_release(struct pe WARN_ON_ONCE(nr_bytes & (PAGE_SIZE - 1)); nr_pages = nr_bytes >> PAGE_SHIFT; - spin_lock_irqsave(&css_set_lock, flags); if (nr_pages) obj_cgroup_uncharge_pages(objcg, nr_pages); + + spin_lock_irqsave(&css_set_lock, flags); list_del(&objcg->list); spin_unlock_irqrestore(&css_set_lock, flags); _ Patches currently in -mm which might be from songmuchun@xxxxxxxxxxxxx are mm-memcontrol-fix-root_mem_cgroup-charging.patch mm-memcontrol-fix-page-charging-in-page-replacement.patch mm-memcontrol-bail-out-early-when-mm-in-get_mem_cgroup_from_mm.patch mm-memcontrol-remove-the-pgdata-parameter-of-mem_cgroup_page_lruvec.patch mm-memcontrol-simplify-lruvec_holds_page_lru_lock.patch mm-memcontrol-rename-lruvec_holds_page_lru_lock-to-page_matches_lruvec.patch mm-memcontrol-simplify-the-logic-of-objcg-pinning-memcg.patch mm-memcontrol-move-obj_cgroup_uncharge_pages-out-of-css_set_lock.patch mm-vmscan-remove-noinline_for_stack.patch mm-memory_hotplug-factor-out-bootmem-core-functions-to-bootmem_infoc.patch mm-hugetlb-introduce-a-new-config-hugetlb_page_free_vmemmap.patch mm-hugetlb-gather-discrete-indexes-of-tail-page.patch mm-hugetlb-free-the-vmemmap-pages-associated-with-each-hugetlb-page.patch mm-hugetlb-defer-freeing-of-hugetlb-pages.patch mm-hugetlb-alloc-the-vmemmap-pages-associated-with-each-hugetlb-page.patch mm-hugetlb-add-a-kernel-parameter-hugetlb_free_vmemmap.patch mm-memory_hotplug-disable-memmap_on_memory-when-hugetlb_free_vmemmap-enabled.patch mm-hugetlb-introduce-nr_free_vmemmap_pages-in-the-struct-hstate.patch