MIME-Version: 1.0
References: <20211213165342.74704-1-songmuchun@bytedance.com>
 <20211213165342.74704-3-songmuchun@bytedance.com> <YbihOFJHqvQ9hsjO@cmpxchg.org>
In-Reply-To: <YbihOFJHqvQ9hsjO@cmpxchg.org>
From:   Muchun Song <songmuchun@bytedance.com>
Date:   Wed, 15 Dec 2021 20:34:45 +0800
Message-ID: <CAMZfGtVTztinpOTCAAWW+0Q7SAcGfFW4PVW+bHnFQLN-nDBwSg@mail.gmail.com>
Subject: Re: [PATCH v4 02/17] mm: introduce kmem_cache_alloc_lru
To:     Johannes Weiner <hannes@cmpxchg.org>
Cc:     Matthew Wilcox <willy@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@kernel.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        Shakeel Butt <shakeelb@google.com>,
        Roman Gushchin <guro@fb.com>, Yang Shi <shy828301@gmail.com>,
        Alex Shi <alexs@kernel.org>,
        Wei Yang <richard.weiyang@gmail.com>,
        Dave Chinner <david@fromorbit.com>,
        trond.myklebust@hammerspace.com, anna.schumaker@netapp.com,
        jaegeuk@kernel.org, chao@kernel.org,
        Kari Argillander <kari.argillander@gmail.com>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux Memory Management List <linux-mm@kvack.org>,
        linux-nfs@vger.kernel.org, Qi Zheng <zhengqi.arch@bytedance.com>,
        Xiongchun duan <duanxiongchun@bytedance.com>,
        fam.zheng@bytedance.com, Muchun Song <smuchun@gmail.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Tue, Dec 14, 2021 at 9:50 PM Johannes Weiner <hannes@cmpxchg.org> wrote:
>
> On Tue, Dec 14, 2021 at 12:53:27AM +0800, Muchun Song wrote:
> > +/*
> > + * The allocated list lru pointers array is not accounted directly.
> > + * Moreover, it should not come from DMA buffer and is not readily
> > + * reclaimable. So those GFP bits should be masked off.
> > + */
> > +#define LRUS_CLEAR_MASK      (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT | __GFP_ZERO)
>
> There is already GFP_RECLAIM_MASK for this purpose, you can use that.

Cool. Thanks.

>
> > +int memcg_list_lru_alloc(struct mem_cgroup *memcg, struct list_lru *lru,
> > +                      gfp_t gfp)
> > +{
> > +     int i;
> > +     unsigned long flags;
> > +     struct list_lru_memcg *mlrus;
> > +     struct list_lru_memcg_table {
> > +             struct list_lru_per_memcg *mlru;
> > +             struct mem_cgroup *memcg;
> > +     } *table;
> > +
> > +     if (!list_lru_memcg_aware(lru) || memcg_list_lru_allocated(memcg, lru))
> > +             return 0;
> > +
> > +     gfp &= ~LRUS_CLEAR_MASK;
>
>         gfp &= GFP_RECLAIM_MASK;