From: Shakeel Butt <shakeelb@google.com>
To: Abel Wu <wuyun.abel@bytedance.com>
Cc: "David S . Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Vladimir Davydov <vdavydov.dev@gmail.com>,
Muchun Song <muchun.song@linux.dev>,
Simon Horman <simon.horman@corigine.com>,
netdev@vger.kernel.org, linux-mm@kvack.org,
cgroups@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next v5 1/3] net-memcg: Fold dependency into memcg pressure cond
Date: Fri, 2 Jun 2023 20:25:49 +0000 [thread overview]
Message-ID: <20230602202549.7nvrv4bx4cu7qxdn@google.com> (raw)
In-Reply-To: <20230602081135.75424-2-wuyun.abel@bytedance.com>
On Fri, Jun 02, 2023 at 04:11:33PM +0800, Abel Wu wrote:
> The callers of mem_cgroup_under_socket_pressure() should always make
> sure that (mem_cgroup_sockets_enabled && sk->sk_memcg) is true. So
> instead of coding around all the callsites, put the dependencies into
> mem_cgroup_under_socket_pressure() to avoid redundancy and possibly
> bugs.
>
> This change might also introduce slight function call overhead *iff*
> the function gets expanded in the future. But for now this change
> doesn't make binaries different (checked by vimdiff) except the one
> net/ipv4/tcp_input.o (by scripts/bloat-o-meter), which is probably
> negligible to performance:
>
> add/remove: 0/0 grow/shrink: 1/2 up/down: 5/-5 (0)
> Function old new delta
> tcp_grow_window 573 578 +5
> tcp_try_rmem_schedule 1083 1081 -2
> tcp_check_space 324 321 -3
> Total: Before=44647, After=44647, chg +0.00%
>
> So folding the dependencies into mem_cgroup_under_socket_pressure()
> is generally a good thing and provides better readablility.
>
I don't see how it is improving readability. If you have removed the use
of mem_cgroup_sockets_enabled completely from the networking then I can
understand but this change IMHO will actually decrease the readability
because the later readers will have to reason why we are doing this
check at some places but not other.
next prev parent reply other threads:[~2023-06-02 20:25 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-02 8:11 [PATCH net-next v5 0/3] sock: Improve condition on sockmem pressure Abel Wu
2023-06-02 8:11 ` [PATCH net-next v5 1/3] net-memcg: Fold dependency into memcg pressure cond Abel Wu
2023-06-02 20:25 ` Shakeel Butt [this message]
2023-06-05 11:52 ` Abel Wu
2023-06-02 8:11 ` [PATCH net-next v5 2/3] sock: Always take memcg pressure into consideration Abel Wu
2023-06-02 20:41 ` Shakeel Butt
2023-06-04 10:36 ` Willem de Bruijn
2023-06-05 3:44 ` Abel Wu
2023-06-05 8:27 ` Paolo Abeni
2023-06-05 9:57 ` Abel Wu
2023-06-02 8:11 ` [PATCH net-next v5 3/3] sock: Fix misuse of sk_under_memory_pressure() Abel Wu
2023-06-02 20:53 ` Shakeel Butt
2023-06-05 8:34 ` Abel Wu
2023-06-06 8:39 ` kernel test robot
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230602202549.7nvrv4bx4cu7qxdn@google.com \
--to=shakeelb@google.com \
--cc=cgroups@vger.kernel.org \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=hannes@cmpxchg.org \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=muchun.song@linux.dev \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=simon.horman@corigine.com \
--cc=vdavydov.dev@gmail.com \
--cc=wuyun.abel@bytedance.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).