netdev - Re: [RFC PATCH bpf-next v5 12/12] samples/bpf: Add memcg priority control example

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <25d7b7ce5d8358f2d2dd9fc50e74596872b86aae1488b67cea6f85715e8f91de@mail.kernel.org>
Date: Tue, 27 Jan 2026 10:08:29 +0000 (UTC)
From: bot+bpf-ci@...nel.org
To: hui.zhu@...ux.dev,akpm@...ux-foundation.org,hannes@...xchg.org,mhocko@...nel.org,roman.gushchin@...ux.dev,shakeel.butt@...ux.dev,muchun.song@...ux.dev,ast@...nel.org,daniel@...earbox.net,andrii@...nel.org,martin.lau@...ux.dev,eddyz87@...il.com,song@...nel.org,yonghong.song@...ux.dev,john.fastabend@...il.com,kpsingh@...nel.org,sdf@...ichev.me,haoluo@...gle.com,jolsa@...nel.org,shuah@...nel.org,peterz@...radead.org,ojeda@...nel.org,nathan@...nel.org,kees@...nel.org,tj@...nel.org,jeffxu@...omium.org,mkoutny@...e.com,kernel@...rr.cc,brauner@...nel.org,rdunlap@...radead.org,brgerst@...il.com,masahiroy@...nel.org,davem@...emloft.net,kuba@...nel.org,hawk@...nel.org,inwardvessel@...il.com,willemb@...gle.com,kerneljasonxing@...il.com,paul.chaignon@...il.com,a.s.protopopov@...il.com,ameryhung@...il.com,chenridong@...weicloud.com,lance.yang@...ux.dev,jiayuan.chen@...ux.dev,linux-kernel@...r.kernel.org,linux-mm@...ck.org,cgroups@...r.kernel.org,bpf@...r.kernel.org,netdev@...r.kernel.org,linu
 x-kselftest@...r.kernel.org
Cc: zhuhui@...inos.cn,geliang@...nel.org,ast@...nel.org,andrii@...nel.org,daniel@...earbox.net,martin.lau@...nel.org,eddyz87@...il.com,yonghong.song@...ux.dev,clm@...a.com,ihor.solodrai@...ux.dev
Subject: Re: [RFC PATCH bpf-next v5 12/12] samples/bpf: Add memcg priority control example

> diff --git a/samples/bpf/memcg.bpf.c b/samples/bpf/memcg.bpf.c
> new file mode 100644
> index 000000000000..e611ac0e641a
> --- /dev/null
> +++ b/samples/bpf/memcg.bpf.c

[ ... ]

> +SEC("tp/memcg/count_memcg_events")
> +int
> +handle_count_memcg_events(struct trace_event_raw_memcg_rstat_events *ctx)
> +{
> +	u32 key = 0;
> +	struct AggregationData *data;
> +	u64 current_ts;
> +
> +	if (ctx->id != local_config.high_cgroup_id ||
> +	    (ctx->item != PGFAULT))
                         ^^^^^^^

The BPF code monitors PGFAULT events here.

> diff --git a/samples/bpf/memcg.c b/samples/bpf/memcg.c
> new file mode 100644
> index 000000000000..0c47ed53f6ae
> --- /dev/null
> +++ b/samples/bpf/memcg.c

[ ... ]

> +static void usage(char *name)
> +{

[ ... ]

> +	fprintf(stderr,
> +		"  -t, --threshold=VALUE  The sum of 'val' PGSCAN of\n");
                                                     ^^^^^^

Should this say PGFAULT instead of PGSCAN? The commit message and the BPF
code in memcg.bpf.c both indicate that the program monitors PGFAULT events,
but the help text here mentions PGSCAN.


---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md

CI run summary: https://github.com/kernel-patches/bpf/actions/runs/21392729810

AI-authorship-score: low
AI-authorship-explanation: Code is a straightforward adaptation of existing selftest code with standard kernel patterns; documentation error is more consistent with human copy-paste mistake than AI generation.
issues-found: 1
issue-severity-score: low
issue-severity-explanation: Documentation mismatch in help text (PGSCAN vs PGFAULT) could cause user confusion but has no runtime impact.