From: Yang Shi <shy828301@gmail.com>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Roman Gushchin <guro@fb.com>, Kirill Tkhai <ktkhai@virtuozzo.com>,
Shakeel Butt <shakeelb@google.com>,
Dave Chinner <david@fromorbit.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@suse.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linux MM <linux-mm@kvack.org>,
Linux FS-devel Mailing List <linux-fsdevel@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [v5 PATCH 07/11] mm: vmscan: add per memcg shrinker nr_deferred
Date: Mon, 1 Feb 2021 09:09:45 -0800 [thread overview]
Message-ID: <CAHbLzkpCLxzy-whY8jiSw59V-tmq=VgDuxyUcdRkWrgkZnxC2w@mail.gmail.com> (raw)
In-Reply-To: <0ce8b6e4-5abb-3edb-8423-f6c222420a89@suse.cz>
On Mon, Feb 1, 2021 at 7:17 AM Vlastimil Babka <vbabka@suse.cz> wrote:
>
> On 1/29/21 7:04 PM, Yang Shi wrote:
>
> >> > > @@ -209,9 +214,15 @@ static int expand_one_shrinker_info(struct mem_cgroup *memcg,
> >> > > if (!new)
> >> > > return -ENOMEM;
> >> > >
> >> > > - /* Set all old bits, clear all new bits */
> >> > > - memset(new->map, (int)0xff, old_size);
> >> > > - memset((void *)new->map + old_size, 0, size - old_size);
> >> > > + new->map = (unsigned long *)(new + 1);
> >> > > + new->nr_deferred = (void *)new->map + m_size;
> >> >
> >> > This better be aligned to sizeof(atomic_long_t). Can we be sure about that?
> >>
> >> Good point. No, if unsigned long is 32 bit on some 64 bit machines.
> >
> > I think we could just change map to "u64" and guarantee struct
> > shrinker_info is aligned to 64 bit.
>
> What about changing to order, nr_deferred before map? Then the atomics are at
> the beginning of allocated area, thus aligned.
Yes, it works too. The rcu_head is guaranteed to have aligned at sizeof(void *).
Will fix in v6.
next prev parent reply other threads:[~2021-02-01 17:10 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-27 23:33 [v5 PATCH 0/11] Make shrinker's nr_deferred memcg aware Yang Shi
2021-01-27 23:33 ` [v5 PATCH 01/11] mm: vmscan: use nid from shrink_control for tracepoint Yang Shi
2021-01-28 16:02 ` Vlastimil Babka
2021-01-27 23:33 ` [v5 PATCH 02/11] mm: vmscan: consolidate shrinker_maps handling code Yang Shi
2021-01-28 16:10 ` Vlastimil Babka
2021-01-28 21:16 ` Yang Shi
2021-01-29 14:33 ` Kirill Tkhai
2021-01-29 17:11 ` Yang Shi
2021-01-27 23:33 ` [v5 PATCH 03/11] mm: vmscan: use shrinker_rwsem to protect shrinker_maps allocation Yang Shi
2021-01-28 16:19 ` Vlastimil Babka
2021-01-27 23:33 ` [v5 PATCH 04/11] mm: vmscan: remove memcg_shrinker_map_size Yang Shi
2021-01-28 16:53 ` Vlastimil Babka
2021-01-28 21:22 ` Yang Shi
2021-01-29 11:22 ` Vlastimil Babka
2021-01-29 17:05 ` Yang Shi
2021-01-27 23:33 ` [v5 PATCH 05/11] mm: memcontrol: rename shrinker_map to shrinker_info Yang Shi
2021-01-28 17:38 ` Vlastimil Babka
2021-01-28 22:05 ` Yang Shi
2021-01-27 23:33 ` [v5 PATCH 06/11] mm: vmscan: use a new flag to indicate shrinker is registered Yang Shi
2021-01-28 17:56 ` Vlastimil Babka
2021-01-28 23:47 ` Yang Shi
2021-01-27 23:33 ` [v5 PATCH 07/11] mm: vmscan: add per memcg shrinker nr_deferred Yang Shi
2021-01-29 13:00 ` Vlastimil Babka
2021-01-29 14:46 ` Kirill Tkhai
2021-01-29 17:20 ` Yang Shi
2021-01-29 18:04 ` Yang Shi
2021-02-01 15:17 ` Vlastimil Babka
2021-02-01 17:09 ` Yang Shi [this message]
2021-01-27 23:33 ` [v5 PATCH 08/11] mm: vmscan: use per memcg nr_deferred of shrinker Yang Shi
2021-01-29 14:55 ` Kirill Tkhai
2021-01-29 14:59 ` Kirill Tkhai
2021-01-29 17:22 ` Yang Shi
2021-01-29 15:13 ` Vlastimil Babka
2021-01-29 17:33 ` Yang Shi
2021-01-27 23:33 ` [v5 PATCH 09/11] mm: vmscan: don't need allocate shrinker->nr_deferred for memcg aware shrinkers Yang Shi
2021-01-29 15:40 ` Vlastimil Babka
2021-01-29 17:34 ` Yang Shi
2021-01-27 23:33 ` [v5 PATCH 10/11] mm: memcontrol: reparent nr_deferred when memcg offline Yang Shi
2021-01-29 15:52 ` Vlastimil Babka
2021-01-29 17:38 ` Yang Shi
2021-01-27 23:33 ` [v5 PATCH 11/11] mm: vmscan: shrink deferred objects proportional to priority Yang Shi
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