From: Geliang Tang <geliang.tang@suse.com>
To: Paolo Abeni <pabeni@redhat.com>
Cc: mptcp@lists.linux.dev
Subject: Re: [PATCH mptcp-next v11 10/11] Squash to "selftests/bpf: Add bpf_rr scheduler"
Date: Tue, 4 Jul 2023 10:06:54 +0800 [thread overview]
Message-ID: <20230704020654.GA27381@localhost> (raw)
In-Reply-To: <d005f0e6692d6fdb175b5366c1b7afe253f7930e.camel@redhat.com>
On Mon, Jul 03, 2023 at 05:38:39PM +0200, Paolo Abeni wrote:
> On Tue, 2023-06-27 at 09:06 +0800, Geliang Tang wrote:
> > Use sk_storage to store last_snd, instead of using msk->last_snd.
> >
> > Signed-off-by: Geliang Tang <geliang.tang@suse.com>
> > ---
> > tools/testing/selftests/bpf/bpf_tcp_helpers.h | 6 ++-
> > .../selftests/bpf/progs/mptcp_bpf_rr.c | 44 ++++++++++++++-----
> > 2 files changed, 39 insertions(+), 11 deletions(-)
> >
> > diff --git a/tools/testing/selftests/bpf/bpf_tcp_helpers.h b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
> > index b4b766c7a68f..945dd46c98c0 100644
> > --- a/tools/testing/selftests/bpf/bpf_tcp_helpers.h
> > +++ b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
> > @@ -259,7 +259,6 @@ struct mptcp_sched_ops {
> > struct mptcp_sock {
> > struct inet_connection_sock sk;
> >
> > - struct sock *last_snd;
> > __u32 token;
> > struct sock *first;
> > char ca_name[TCP_CA_NAME_MAX];
> > @@ -271,5 +270,10 @@ extern void mptcp_sched_data_set_contexts(const struct mptcp_sock *msk,
> > struct mptcp_sched_data *data) __ksym;
> > extern struct mptcp_subflow_context *
> > mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned int pos) __ksym;
> > +static inline struct sock *
> > +mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
> > +{
> > + return subflow->tcp_sock;
> > +}
> >
> > #endif
> > diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
> > index e101428e5906..21144e96ba56 100644
> > --- a/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
> > +++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
> > @@ -6,33 +6,49 @@
> >
> > char _license[] SEC("license") = "GPL";
> >
> > +struct mptcp_rr_storage {
> > + struct sock *last_snd;
> > +};
> > +struct sock *last_snd;
> > +
> > +struct {
> > + __uint(type, BPF_MAP_TYPE_SK_STORAGE);
> > + __uint(map_flags, BPF_F_NO_PREALLOC);
> > + __type(key, int);
> > + __type(value, struct mptcp_rr_storage);
> > +} mptcp_rr_map SEC(".maps");
> > +
> > SEC("struct_ops/mptcp_sched_rr_init")
> > -void BPF_PROG(mptcp_sched_rr_init, const struct mptcp_sock *msk)
> > +void BPF_PROG(mptcp_sched_rr_init, struct mptcp_sock *msk)
> > {
> > }
> >
> > SEC("struct_ops/mptcp_sched_rr_release")
> > -void BPF_PROG(mptcp_sched_rr_release, const struct mptcp_sock *msk)
> > +void BPF_PROG(mptcp_sched_rr_release, struct mptcp_sock *msk)
> > {
> > + bpf_sk_storage_delete(&mptcp_rr_map, msk);
> > }
> >
> > -void BPF_STRUCT_OPS(bpf_rr_data_init, const struct mptcp_sock *msk,
> > +void BPF_STRUCT_OPS(bpf_rr_data_init, struct mptcp_sock *msk,
> > struct mptcp_sched_data *data)
> > {
> > mptcp_sched_data_set_contexts(msk, data);
> > }
> >
> > -int BPF_STRUCT_OPS(bpf_rr_get_subflow, const struct mptcp_sock *msk,
> > - struct mptcp_sched_data *data)
> > +int BPF_STRUCT_OPS(bpf_rr_get_subflow, struct mptcp_sock *msk,
> > + const struct mptcp_sched_data *data)
> > {
> > + struct mptcp_subflow_context *subflow;
> > + struct mptcp_rr_storage *ptr;
> > int nr = 0;
> >
> > - for (int i = 0; i < MPTCP_SUBFLOWS_MAX; i++) {
> > - if (!msk->last_snd || !data->contexts[i])
> > + for (int i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
> > + subflow = mptcp_subflow_ctx_by_pos(data, i);
> > + if (!last_snd || !subflow)
>
> It looks like this is accessing a global variable ('last_snd'), which
> is probably not very safe.
Yes, it's should be a local variable. I just sent a patch to ML to fix
this:
https://patchwork.kernel.org/project/mptcp/patch/0b57bf87dc30e15782ba1fe2e925a7ce6ef0fc90.1688434547.git.geliang.tang@suse.com/
>
> I think you could instead use inet_csk(msk)->icsk_ca_priv - currently
> unused.
>
> As this is the only comment I have, no need to send a whole v12. I
> think we can merge the series as-is and then squash the needed change
> to replace the global variable and map used here with inet_csk(msk)-
> >icsk_ca_priv.
One of the purposes of this test is to demonstrate an example of using a
bpf map to store persistent schedulers data, so I prefer to use the bpf
map to implement it here.
Using inet_csk(msk)->icsk_ca_priv is much more complex. We need to add
the special write accesses for icsk_ca_priv.
Thanks,
-Geliang
>
> Thanks!
>
> Paolo
>
next prev parent reply other threads:[~2023-07-04 2:06 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-27 1:06 [PATCH mptcp-next v11 00/11] BPF packet scheduler updates part 1 Geliang Tang
2023-06-27 1:06 ` [PATCH mptcp-next v11 01/11] Squash to "mptcp: drop last_snd and MPTCP_RESET_SCHEDULER" Geliang Tang
2023-06-27 1:06 ` [PATCH mptcp-next v11 02/11] Squash to "mptcp: add struct mptcp_sched_ops" Geliang Tang
2023-06-27 1:06 ` [PATCH mptcp-next v11 03/11] Squash to "mptcp: add sched_data_set_contexts helper" Geliang Tang
2023-07-13 7:15 ` Geliang Tang
2023-07-13 8:50 ` Matthieu Baerts
2023-06-27 1:06 ` [PATCH mptcp-next v11 04/11] mptcp: register default scheduler Geliang Tang
2023-06-27 1:06 ` [PATCH mptcp-next v11 05/11] Squash to "bpf: Add bpf_mptcp_sched_ops" Geliang Tang
2023-06-27 1:06 ` [PATCH mptcp-next v11 06/11] Squash to "bpf: Add bpf_mptcp_sched_kfunc_set" Geliang Tang
2023-06-27 1:06 ` [PATCH mptcp-next v11 07/11] Squash to "selftests/bpf: Add mptcp sched structs" Geliang Tang
2023-06-27 1:06 ` [PATCH mptcp-next v11 08/11] Squash to "selftests/bpf: Add bpf_first scheduler" Geliang Tang
2023-06-27 1:06 ` [PATCH mptcp-next v11 09/11] Squash to "selftests/bpf: Add bpf_bkup scheduler" Geliang Tang
2023-06-27 1:06 ` [PATCH mptcp-next v11 10/11] Squash to "selftests/bpf: Add bpf_rr scheduler" Geliang Tang
2023-07-03 15:38 ` Paolo Abeni
2023-07-04 2:06 ` Geliang Tang [this message]
2023-06-27 1:06 ` [PATCH mptcp-next v11 11/11] Squash to "selftests/bpf: Add bpf_red scheduler" Geliang Tang
2023-06-27 1:29 ` Squash to "selftests/bpf: Add bpf_red scheduler": Tests Results MPTCP CI
2023-06-27 9:13 ` MPTCP CI
2023-07-05 9:11 ` [PATCH mptcp-next v11 00/11] BPF packet scheduler updates part 1 Matthieu Baerts
2023-07-05 17:53 ` Mat Martineau
2023-07-06 8:49 ` Geliang Tang
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=20230704020654.GA27381@localhost \
--to=geliang.tang@suse.com \
--cc=mptcp@lists.linux.dev \
--cc=pabeni@redhat.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