From: Shakeel Butt <shakeel.butt@linux.dev>
To: "T.J. Mercier" <tjmercier@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Roman Gushchin <roman.gushchin@linux.dev>,
Muchun Song <muchun.song@linux.dev>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 3/7] memcg: reduce memory for the lruvec and memcg stats
Date: Mon, 29 Apr 2024 13:13:05 -0700 [thread overview]
Message-ID: <j4dsapl5hu2enzoq5c7y3z2bqksk6fpygkk5t45ok7d5v3gdt2@5ygpjaj2hiva> (raw)
In-Reply-To: <CABdmKX0Mo74f-AjY46cyPwd2qSpwmj4CLvYVCEywq_PEsVmd9w@mail.gmail.com>
On Mon, Apr 29, 2024 at 10:35:38AM -0700, T.J. Mercier wrote:
> On Fri, Apr 26, 2024 at 5:37 PM Shakeel Butt <shakeel.butt@linux.dev> wrote:
> >
[...]
> > +
> > +static const unsigned int memcg_stat_items[] = {
> > + MEMCG_SWAP,
> > + MEMCG_SOCK,
> > + MEMCG_PERCPU_B,
> > + MEMCG_VMALLOC,
> > + MEMCG_KMEM,
> > + MEMCG_ZSWAP_B,
> > + MEMCG_ZSWAPPED,
> > +};
>
> Unsigned for these? All the values are positive now, but I don't think
> we'll get a build warning if a negative one ever got added, just a
> crash or corruption. BUG_ON in init_memcg_stats if a
> memcg_stat_items[i] < 0?
We are depending on NR_VM_NODE_STAT_ITEMS to tell the number of elements
for vmstats. So, I think there is an implicit assumption that there are
no negative enums in enum node_stat_item. So, if we want to verify those
assumptions then we should be adding such warnings/build-bugs in vmstat
first.
next prev parent reply other threads:[~2024-04-29 20:13 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-27 0:37 [PATCH v2 0/7] memcg: reduce memory consumption by memcg stats Shakeel Butt
2024-04-27 0:37 ` [PATCH v2 1/7] memcg: reduce memory size of mem_cgroup_events_index Shakeel Butt
2024-04-27 0:42 ` Yosry Ahmed
2024-04-27 1:15 ` Shakeel Butt
2024-04-29 15:36 ` Roman Gushchin
2024-04-27 0:37 ` [PATCH v2 2/7] memcg: dynamically allocate lruvec_stats Shakeel Butt
2024-04-27 1:23 ` Yosry Ahmed
2024-04-29 15:50 ` Roman Gushchin
2024-04-29 19:46 ` Shakeel Butt
2024-04-29 21:02 ` Roman Gushchin
2024-04-29 21:59 ` Shakeel Butt
2024-04-27 0:37 ` [PATCH v2 3/7] memcg: reduce memory for the lruvec and memcg stats Shakeel Butt
2024-04-27 0:51 ` Yosry Ahmed
2024-04-27 1:16 ` Shakeel Butt
2024-04-27 1:18 ` Yosry Ahmed
2024-04-29 16:00 ` Roman Gushchin
2024-04-29 20:00 ` Shakeel Butt
2024-04-29 17:35 ` T.J. Mercier
2024-04-29 20:13 ` Shakeel Butt [this message]
2024-04-29 22:23 ` T.J. Mercier
2024-04-27 0:37 ` [PATCH v2 4/7] memcg: cleanup __mod_memcg_lruvec_state Shakeel Butt
2024-04-27 0:53 ` Yosry Ahmed
2024-04-29 15:45 ` Roman Gushchin
2024-04-27 0:37 ` [PATCH v2 5/7] memcg: pr_warn_once for unexpected events and stats Shakeel Butt
2024-04-27 0:58 ` Yosry Ahmed
2024-04-27 1:18 ` Shakeel Butt
2024-04-27 14:22 ` Johannes Weiner
2024-04-29 19:54 ` Shakeel Butt
2024-04-29 16:06 ` Roman Gushchin
2024-04-29 19:56 ` Shakeel Butt
2024-04-27 0:37 ` [PATCH v2 6/7] memcg: use proper type for mod_memcg_state Shakeel Butt
2024-04-27 0:37 ` [PATCH v2 7/7] mm: cleanup WORKINGSET_NODES in workingset Shakeel Butt
2024-04-29 16:07 ` Roman Gushchin
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