netdev - Re: [RFC PATCH bpf-next 0/2] Remove unnecessary synchronizations in cpumap

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]

Date: Thu, 10 Aug 2023 11:22:43 +0800
From: Hou Tao <houtao@...weicloud.com>
To: bpf@...r.kernel.org, netdev@...r.kernel.org
Cc: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski
 <kuba@...nel.org>, Jesper Dangaard Brouer <hawk@...nel.org>,
 John Fastabend <john.fastabend@...il.com>,
 Björn Töpel <bjorn.topel@...il.com>,
 Toke Høiland-Jørgensen <toke@...hat.com>,
 Martin KaFai Lau <martin.lau@...ux.dev>,
 Alexei Starovoitov <alexei.starovoitov@...il.com>,
 Andrii Nakryiko <andrii@...nel.org>, Song Liu <song@...nel.org>,
 Hao Luo <haoluo@...gle.com>, Yonghong Song <yonghong.song@...ux.dev>,
 Daniel Borkmann <daniel@...earbox.net>, KP Singh <kpsingh@...nel.org>,
 Stanislav Fomichev <sdf@...gle.com>, Jiri Olsa <jolsa@...nel.org>,
 "houtao1@...wei.com" <houtao1@...wei.com>
Subject: Re: [RFC PATCH bpf-next 0/2] Remove unnecessary synchronizations in
 cpumap

ping ? Any feedback about this patch set ?

On 7/28/2023 10:30 AM, Hou Tao wrote:
> From: Hou Tao <houtao1@...wei.com>
>
> Hi,
>
> The patchset aims to remove unnecessary synchronizations in cpu-map
> which were found during code inspection. Patch #1 removes the
> unnecessary rcu_barrier() when freeing bpf_cpu_map_entry and replaces
> it by queue_rcu_work(). Patch #2 removes the unnecessary call_rcu()
> and queue_work() when destroying cpu-map and does the freeing directly.
>
> Simply testing the patchset by running xdp_redirect_cpu test for
> virtio-net and no issues are reported. Hope to get more feedback before
> removing the RFC tag. As ususal, comments and suggestions are always
> welcome.
>
> Regards,
> Tao
>
> Hou Tao (2):
>   bpf, cpumap: Use queue_rcu_work() to remove unnecessary rcu_barrier()
>   bpf, cpumap: Clean up bpf_cpu_map_entry directly in cpu_map_free
>
>  kernel/bpf/cpumap.c | 110 +++++++++++++-------------------------------
>  1 file changed, 31 insertions(+), 79 deletions(-)
>