lkml.org 
[lkml]   [2021]   [May]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC PATCH v3 02/12] mm: memcontrol: introduce compact_lock_page_lruvec_irqsave
    On Wed, Apr 21, 2021 at 03:00:49PM +0800, Muchun Song wrote:
    > If we reuse the objcg APIs to charge LRU pages, the page_memcg()
    > can be changed when the LRU pages reparented. In this case, we need
    > to acquire the new lruvec lock.
    >
    > lruvec = mem_cgroup_page_lruvec(page);
    >
    > // The page is reparented.
    >
    > compact_lock_irqsave(&lruvec->lru_lock, &flags, cc);
    >
    > // Acquired the wrong lruvec lock and need to retry.
    >
    > But compact_lock_irqsave() only take lruvec lock as the parameter,
    > we cannot aware this change. If it can take the page as parameter
    > to acquire the lruvec lock. When the page memcg is changed, we can
    > use the page_memcg() detect whether we need to reacquire the new
    > lruvec lock. So compact_lock_irqsave() is not suitable for us.
    > Similar to lock_page_lruvec_irqsave(), introduce
    > compact_lock_page_lruvec_irqsave() to acquire the lruvec lock in
    > the compaction routine.
    >
    > Signed-off-by: Muchun Song <songmuchun@bytedance.com>

    Acked-by: Roman Gushchin <guro@fb.com>

    > ---
    > mm/compaction.c | 27 ++++++++++++++++++++++++---
    > 1 file changed, 24 insertions(+), 3 deletions(-)
    >
    > diff --git a/mm/compaction.c b/mm/compaction.c
    > index 1c500e697c88..082293587cc6 100644
    > --- a/mm/compaction.c
    > +++ b/mm/compaction.c
    > @@ -511,6 +511,29 @@ static bool compact_lock_irqsave(spinlock_t *lock, unsigned long *flags,
    > return true;
    > }
    >
    > +static struct lruvec *
    > +compact_lock_page_lruvec_irqsave(struct page *page, unsigned long *flags,
    > + struct compact_control *cc)

    Maybe compact_lock_page_irqsave() to make it more similar to
    compact_lock_irqsafe()? But it's up to you.

    Thanks!

    \
     
     \ /
      Last update: 2021-05-25 19:23    [W:4.158 / U:0.128 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site