From: Vlastimil Babka <vbabka@suse.cz>
To: Alex Shi <alex.shi@linux.alibaba.com>,
akpm@linux-foundation.org, mgorman@techsingularity.net,
tj@kernel.org, hughd@google.com, khlebnikov@yandex-team.ru,
daniel.m.jordan@oracle.com, willy@infradead.org,
hannes@cmpxchg.org, lkp@intel.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
shakeelb@google.com, iamjoonsoo.kim@lge.com,
richard.weiyang@gmail.com, kirill@shutemov.name,
alexander.duyck@gmail.com, rong.a.chen@intel.com,
mhocko@suse.com, vdavydov.dev@gmail.com, shy828301@gmail.com
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: Re: [PATCH v21 12/19] mm/mlock: remove lru_lock on TestClearPageMlocked
Date: Wed, 11 Nov 2020 14:03:54 +0100 [thread overview]
Message-ID: <0df624ca-a0d2-6a9f-f114-04f91bf35415@suse.cz> (raw)
In-Reply-To: <1604566549-62481-13-git-send-email-alex.shi@linux.alibaba.com>
On 11/5/20 9:55 AM, Alex Shi wrote:
> In the func munlock_vma_page, comments mentained lru_lock needed for
> serialization with split_huge_pages. But the page must be PageLocked
> as well as pages in split_huge_page series funcs. Thus the PageLocked
> is enough to serialize both funcs.
>
> Further more, Hugh Dickins pointed: before splitting in
> split_huge_page_to_list, the page was unmap_page() to remove pmd/ptes
> which protect the page from munlock. Thus, no needs to guard
> __split_huge_page_tail for mlock clean, just keep the lru_lock there for
> isolation purpose.
>
> LKP found a preempt issue on __mod_zone_page_state which need change
> to mod_zone_page_state. Thanks!
>
> Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
> Acked-by: Hugh Dickins <hughd@google.com>
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: linux-mm@kvack.org
> Cc: linux-kernel@vger.kernel.org
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Nit below:
> ---
> mm/mlock.c | 26 +++++---------------------
> 1 file changed, 5 insertions(+), 21 deletions(-)
>
> diff --git a/mm/mlock.c b/mm/mlock.c
> index 884b1216da6a..796c726a0407 100644
> --- a/mm/mlock.c
> +++ b/mm/mlock.c
> @@ -187,40 +187,24 @@ static void __munlock_isolation_failed(struct page *page)
> unsigned int munlock_vma_page(struct page *page)
> {
> int nr_pages;
> - pg_data_t *pgdat = page_pgdat(page);
>
> /* For try_to_munlock() and to serialize with page migration */
Now the reasons for locking are expanded?
> BUG_ON(!PageLocked(page));
> -
> VM_BUG_ON_PAGE(PageTail(page), page);
>
> - /*
> - * Serialize with any parallel __split_huge_page_refcount() which
> - * might otherwise copy PageMlocked to part of the tail pages before
> - * we clear it in the head page. It also stabilizes thp_nr_pages().
> - */
> - spin_lock_irq(&pgdat->lru_lock);
> -
> if (!TestClearPageMlocked(page)) {
> /* Potentially, PTE-mapped THP: do not skip the rest PTEs */
> - nr_pages = 1;
> - goto unlock_out;
> + return 0;
> }
>
> nr_pages = thp_nr_pages(page);
> - __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
> + mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
>
> - if (__munlock_isolate_lru_page(page, true)) {
> - spin_unlock_irq(&pgdat->lru_lock);
> + if (!isolate_lru_page(page))
> __munlock_isolated_page(page);
> - goto out;
> - }
> - __munlock_isolation_failed(page);
> -
> -unlock_out:
> - spin_unlock_irq(&pgdat->lru_lock);
> + else
> + __munlock_isolation_failed(page);
>
> -out:
> return nr_pages - 1;
> }
>
>
next prev parent reply other threads:[~2020-11-11 13:04 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-05 8:55 [PATCH v21 00/19] per memcg lru lock Alex Shi
2020-11-05 8:55 ` [PATCH v21 01/19] mm/thp: move lru_add_page_tail func to huge_memory.c Alex Shi
2020-11-05 8:55 ` [PATCH v21 02/19] mm/thp: use head for head page in lru_add_page_tail Alex Shi
2020-11-05 8:55 ` [PATCH v21 03/19] mm/thp: Simplify lru_add_page_tail() Alex Shi
2020-11-05 8:55 ` [PATCH v21 04/19] mm/thp: narrow lru locking Alex Shi
2020-11-05 8:55 ` [PATCH v21 05/19] mm/vmscan: remove unnecessary lruvec adding Alex Shi
2020-11-11 12:36 ` Vlastimil Babka
2020-11-05 8:55 ` [PATCH v21 06/19] mm/rmap: stop store reordering issue on page->mapping Alex Shi
2020-11-06 1:20 ` Alex Shi
2020-11-10 19:06 ` Johannes Weiner
2020-11-11 7:41 ` Hugh Dickins
2020-11-05 8:55 ` [PATCH v21 07/19] mm: page_idle_get_page() does not need lru_lock Alex Shi
2020-11-10 19:01 ` Johannes Weiner
2020-11-11 8:17 ` huang ying
2020-11-11 12:52 ` Vlastimil Babka
2020-11-05 8:55 ` [PATCH v21 08/19] mm/memcg: add debug checking in lock_page_memcg Alex Shi
2020-11-05 8:55 ` [PATCH v21 09/19] mm/swap.c: fold vm event PGROTATED into pagevec_move_tail_fn Alex Shi
2020-11-05 8:55 ` [PATCH v21 10/19] mm/lru: move lock into lru_note_cost Alex Shi
2020-11-05 8:55 ` [PATCH v21 11/19] mm/vmscan: remove lruvec reget in move_pages_to_lru Alex Shi
2020-11-05 8:55 ` [PATCH v21 12/19] mm/mlock: remove lru_lock on TestClearPageMlocked Alex Shi
2020-11-11 13:03 ` Vlastimil Babka [this message]
2020-11-05 8:55 ` [PATCH v21 13/19] mm/mlock: remove __munlock_isolate_lru_page Alex Shi
2020-11-11 13:07 ` Vlastimil Babka
2020-11-05 8:55 ` [PATCH v21 14/19] mm/lru: introduce TestClearPageLRU Alex Shi
2020-11-11 13:36 ` Vlastimil Babka
2020-11-12 2:03 ` Hugh Dickins
2020-11-12 11:24 ` Vlastimil Babka
2020-11-05 8:55 ` [PATCH v21 15/19] mm/compaction: do page isolation first in compaction Alex Shi
2020-11-11 17:12 ` Vlastimil Babka
2020-11-12 2:28 ` Hugh Dickins
2020-11-12 3:35 ` Alex Shi
2020-11-12 11:25 ` Vlastimil Babka
2020-11-05 8:55 ` [PATCH v21 16/19] mm/swap.c: serialize memcg changes in pagevec_lru_move_fn Alex Shi
2020-11-11 18:00 ` Vlastimil Babka
2020-11-05 8:55 ` [PATCH v21 17/19] mm/lru: replace pgdat lru_lock with lruvec lock Alex Shi
2020-11-05 13:43 ` Alex Shi
2020-11-06 7:48 ` Alex Shi
2020-11-10 18:54 ` Johannes Weiner
2020-11-11 17:46 ` Vlastimil Babka
2020-11-11 17:59 ` Vlastimil Babka
2020-11-12 12:19 ` Vlastimil Babka
2020-11-12 14:19 ` Alex Shi
2020-11-05 8:55 ` [PATCH v21 18/19] mm/lru: introduce the relock_page_lruvec function Alex Shi
2020-11-06 7:50 ` Alex Shi
2020-11-10 18:59 ` Johannes Weiner
2020-11-12 12:31 ` Vlastimil Babka
2020-11-05 8:55 ` [PATCH v21 19/19] mm/lru: revise the comments of lru_lock Alex Shi
2020-11-12 12:37 ` Vlastimil Babka
2020-11-10 12:14 ` [PATCH v21 00/19] per memcg lru lock Alex Shi
2020-11-16 3:45 ` Alex Shi
2020-12-15 0:47 ` Andrew Morton
2020-12-15 2:16 ` Hugh Dickins
2020-12-15 2:28 ` Andrew Morton
2021-01-05 19:30 ` Qian Cai
2021-01-05 19:42 ` Shakeel Butt
2021-01-05 20:11 ` Qian Cai
2021-01-05 21:35 ` Hugh Dickins
2021-01-05 22:01 ` Qian Cai
2021-01-06 3:10 ` Hugh Dickins
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