From: Vasily Averin <vvs@virtuozzo.com>
To: Roman Gushchin <guro@fb.com>
Cc: cgroups@vger.kernel.org, linux-mm@kvack.org,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Vladimir Davydov <vdavydov.dev@gmail.com>
Subject: Re: [PATCH 1/9] memcg: accounting for allocations called with disabled BH
Date: Wed, 10 Mar 2021 12:26:38 +0300 [thread overview]
Message-ID: <e1d40d68-4ba4-8de1-ee04-c644b6f771fe@virtuozzo.com> (raw)
In-Reply-To: <YEfc9uCc8sfs7ooT@carbon.dhcp.thefacebook.com>
On 3/9/21 11:39 PM, Roman Gushchin wrote:
> On Tue, Mar 09, 2021 at 11:03:48AM +0300, Vasily Averin wrote:
>> in_interrupt() check in memcg_kmem_bypass() is incorrect because
>> it does not allow to account memory allocation called from task context
>> with disabled BH, i.e. inside spin_lock_bh()/spin_unlock_bh() sections
>>
>> Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
>
> Good catch!
>
> It looks like the bug was there for years: in_interrupt() was there since
> the commit 7ae1e1d0f8ac ("memcg: kmem controller infrastructure") from 2012!
> So I guess there is no point for a stable fix, but it's definitely nice to
> have it fixed.
I did not noticed that this problem affect existing allocation,
I just found that it blocked accounting of "struct fib6_node" in __ip6_ins_rt()
added in my current patch set. So I do not think it should went to stable@.
Thank you,
Vasily Averin
prev parent reply other threads:[~2021-03-10 9:26 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-09 8:03 Vasily Averin
2021-03-09 14:57 ` Michal Hocko
2021-03-10 9:11 ` Vasily Averin
2021-03-10 9:40 ` Michal Hocko
2021-03-09 19:39 ` Shakeel Butt
2021-03-09 20:18 ` Roman Gushchin
2021-03-10 9:21 ` Vasily Averin
2021-03-10 9:42 ` Michal Hocko
2021-03-10 19:09 ` Roman Gushchin
2021-03-10 9:17 ` Vasily Averin
2021-03-09 20:39 ` Roman Gushchin
2021-03-10 9:26 ` Vasily Averin [this message]
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