The patch titled Subject: mm: memcontrol: fold mem_cgroup_start_move()/mem_cgroup_end_move() has been added to the -mm tree. Its filename is mm-memcontrol-fold-mem_cgroup_start_move-mem_cgroup_end_move.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-memcontrol-fold-mem_cgroup_start_move-mem_cgroup_end_move.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-memcontrol-fold-mem_cgroup_start_move-mem_cgroup_end_move.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/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Johannes Weiner <hannes@xxxxxxxxxxx> Subject: mm: memcontrol: fold mem_cgroup_start_move()/mem_cgroup_end_move() Having these functions and their documentation split out and somewhere makes it harder, not easier, to follow what's going on. Inline them directly where charge moving is prepared and finished, and put an explanation right next to it. Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxx> Cc: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 40 ++++++++++++---------------------------- 1 file changed, 12 insertions(+), 28 deletions(-) diff -puN mm/memcontrol.c~mm-memcontrol-fold-mem_cgroup_start_move-mem_cgroup_end_move mm/memcontrol.c --- a/mm/memcontrol.c~mm-memcontrol-fold-mem_cgroup_start_move-mem_cgroup_end_move +++ a/mm/memcontrol.c @@ -1447,32 +1447,6 @@ int mem_cgroup_swappiness(struct mem_cgr } /* - * memcg->moving_account is used for checking possibility that some thread is - * calling move_account(). When a thread on CPU-A starts moving pages under - * a memcg, other threads should check memcg->moving_account under - * rcu_read_lock(), like this: - * - * CPU-A CPU-B - * rcu_read_lock() - * memcg->moving_account+1 if (memcg->mocing_account) - * take heavy locks. - * synchronize_rcu() update something. - * rcu_read_unlock() - * start move here. - */ - -static void mem_cgroup_start_move(struct mem_cgroup *memcg) -{ - atomic_inc(&memcg->moving_account); - synchronize_rcu(); -} - -static void mem_cgroup_end_move(struct mem_cgroup *memcg) -{ - atomic_dec(&memcg->moving_account); -} - -/* * A routine for checking "mem" is under move_account() or not. * * Checking a cgroup is mc.from or mc.to or under hierarchy of @@ -5412,7 +5386,8 @@ static void mem_cgroup_clear_mc(void) mc.from = NULL; mc.to = NULL; spin_unlock(&mc.lock); - mem_cgroup_end_move(from); + + atomic_dec(&memcg->moving_account); } static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, @@ -5445,7 +5420,16 @@ static int mem_cgroup_can_attach(struct VM_BUG_ON(mc.precharge); VM_BUG_ON(mc.moved_charge); VM_BUG_ON(mc.moved_swap); - mem_cgroup_start_move(from); + + /* + * Signal mem_cgroup_begin_page_stat() to take + * the memcg's move_lock while we're moving + * its pages to another memcg. Then wait for + * already started RCU-only updates to finish. + */ + atomic_inc(&memcg->moving_account); + synchronize_rcu(); + spin_lock(&mc.lock); mc.from = from; mc.to = memcg; _ Patches currently in -mm which might be from hannes@xxxxxxxxxxx are cgroup-kmemleak-add-kmemleak_free-for-cgroup-deallocations.patch mm-page-writeback-inline-account_page_dirtied-into-single-caller.patch mm-memcontrol-fix-missed-end-writeback-page-accounting.patch mm-memcontrol-lockless-page-counters.patch mm-memcontrol-lockless-page-counters-fix.patch mm-memcontrol-lockless-page-counters-fix-fix.patch mm-memcontrol-lockless-page-counters-fix-2.patch mm-hugetlb_cgroup-convert-to-lockless-page-counters.patch kernel-res_counter-remove-the-unused-api.patch kernel-res_counter-remove-the-unused-api-fix.patch kernel-res_counter-remove-the-unused-api-fix-2.patch mm-memcontrol-convert-reclaim-iterator-to-simple-css-refcounting.patch mm-memcontrol-convert-reclaim-iterator-to-simple-css-refcounting-fix.patch mm-memcontrol-take-a-css-reference-for-each-charged-page.patch mm-memcontrol-remove-obsolete-kmemcg-pinning-tricks.patch mm-memcontrol-continue-cache-reclaim-from-offlined-groups.patch mm-memcontrol-remove-synchroneous-stock-draining-code.patch mm-vmscan-count-only-dirty-pages-as-congested.patch memcg-simplify-unreclaimable-groups-handling-in-soft-limit-reclaim.patch mm-memcontrol-update-mem_cgroup_page_lruvec-documentation.patch mm-memcontrol-clarify-migration-where-old-page-is-uncharged.patch memcg-remove-activate_kmem_mutex.patch mm-memcontrol-micro-optimize-mem_cgroup_split_huge_fixup.patch mm-memcontrol-uncharge-pages-on-swapout.patch mm-memcontrol-uncharge-pages-on-swapout-fix.patch mm-memcontrol-remove-unnecessary-pcg_memsw-memoryswap-charge-flag.patch mm-memcontrol-remove-unnecessary-pcg_mem-memory-charge-flag.patch mm-memcontrol-remove-unnecessary-pcg_used-pc-mem_cgroup-valid-flag.patch mm-memcontrol-remove-unnecessary-pcg_used-pc-mem_cgroup-valid-flag-fix.patch mm-memcontrol-inline-memcg-move_lock-locking.patch mm-memcontrol-dont-pass-a-null-memcg-to-mem_cgroup_end_move.patch mm-memcontrol-fold-mem_cgroup_start_move-mem_cgroup_end_move.patch debugging-keep-track-of-page-owners.patch -- 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