From: Quanyang Wang <quanyang.wang@windriver.com>
To: "Michal Koutný" <mkoutny@suse.com>
Cc: Ming Lei <ming.lei@redhat.com>, Tejun Heo <tj@kernel.org>,
Zefan Li <lizefan.x@bytedance.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>, Jens Axboe <axboe@kernel.dk>,
Roman Gushchin <guro@fb.com>,
cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, bpf@vger.kernel.org
Subject: Re: [V2][PATCH] cgroup: fix memory leak caused by missing cgroup_bpf_offline
Date: Fri, 22 Oct 2021 19:03:42 +0800 [thread overview]
Message-ID: <cd4d0dba-6818-12df-1d90-3ef5121e342f@windriver.com> (raw)
In-Reply-To: <YXBRyJMru/RbUQK5@blackbook>
Hi Michal,
On 10/21/21 1:28 AM, Michal Koutný wrote:
> On Wed, Oct 20, 2021 at 01:22:06PM +0800, Quanyang Wang <quanyang.wang@windriver.com> wrote:
>>> If only precpu_ref data is leaked, it is fine to add "Fixes: 2b0d3d3e4fcf",
>>> I thought cgroup_bpf_release() needs to release more for root cgroup, but
>>> looks not true.
>> For now, I can only observe that precpu_ref data is leaked when running ltp
>> testsuite.
>
> I assume you refer to ref->data. I considered the ref->percpu_count_ptr
> allocated with __alloc_percpu_gfp(). Could it be that kmemleak won't
> detect leaked percpu allocations?
Yes, kmemleak can't detect percpu allocations. I find some message about
this:
commit f528f0b8e53d
Author: Catalin Marinas <catalin.marinas@arm.com>
Date: Mon Sep 26 17:12:53 2011 +0100
kmemleak: Handle percpu memory allocation
This patch adds kmemleak callbacks from the percpu allocator, reducing a
number of false positives caused by kmemleak not scanning such memory
blocks. The percpu chunks are never reported as leaks because of current
kmemleak limitations with the __percpu pointer not pointing directly to
the actual chunks.
Thanks,
Quanyang
>
> (The patch you sent resolves this as well, I'm just curious.)
>
> Michal
>
next prev parent reply other threads:[~2021-10-22 11:04 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-18 7:56 [V2][PATCH] cgroup: fix memory leak caused by missing cgroup_bpf_offline quanyang.wang
2021-10-18 9:02 ` Ming Lei
2021-10-18 10:06 ` Quanyang Wang
2021-10-18 12:59 ` Ming Lei
2021-10-19 10:41 ` Quanyang Wang
2021-10-19 17:10 ` Michal Koutný
2021-10-20 2:17 ` Ming Lei
2021-10-20 5:22 ` Quanyang Wang
2021-10-20 17:28 ` Michal Koutný
2021-10-22 11:03 ` Quanyang Wang [this message]
2021-10-20 5:16 ` Quanyang Wang
2021-10-19 10:41 ` Quanyang Wang
2021-10-22 1:30 ` Roman Gushchin
2021-10-22 11:55 ` Quanyang Wang
2021-10-22 21:29 ` Alexei Starovoitov
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