[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20230821-upstream-net-next-20230818-v1-1-0c860fb256a8@kernel.org>
Date: Mon, 21 Aug 2023 15:25:12 -0700
From: Mat Martineau <martineau@...nel.org>
To: Matthieu Baerts <matthieu.baerts@...sares.net>,
"David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>
Cc: netdev@...r.kernel.org, mptcp@...ts.linux.dev,
Geliang Tang <geliang.tang@...e.com>, Mat Martineau <martineau@...nel.org>
Subject: [PATCH net-next 01/10] mptcp: refactor push_pending logic
From: Geliang Tang <geliang.tang@...e.com>
To support redundant package schedulers more easily, this patch refactors
__mptcp_push_pending() logic from:
For each dfrag:
While sends succeed:
Call the scheduler (selects subflow and msk->snd_burst)
Update subflow locks (push/release/acquire as needed)
Send the dfrag data with mptcp_sendmsg_frag()
Update already_sent, snd_nxt, snd_burst
Update msk->first_pending
Push/release on final subflow
->
While first_pending isn't empty:
Call the scheduler (selects subflow and msk->snd_burst)
Update subflow locks (push/release/acquire as needed)
For each pending dfrag:
While sends succeed:
Send the dfrag data with mptcp_sendmsg_frag()
Update already_sent, snd_nxt, snd_burst
Update msk->first_pending
Break if required by msk->snd_burst / etc
Push/release on final subflow
Refactors __mptcp_subflow_push_pending logic from:
For each dfrag:
While sends succeed:
Call the scheduler (selects subflow and msk->snd_burst)
Send the dfrag data with mptcp_subflow_delegate(), break
Send the dfrag data with mptcp_sendmsg_frag()
Update dfrag->already_sent, msk->snd_nxt, msk->snd_burst
Update msk->first_pending
->
While first_pending isn't empty:
Call the scheduler (selects subflow and msk->snd_burst)
Send the dfrag data with mptcp_subflow_delegate(), break
Send the dfrag data with mptcp_sendmsg_frag()
For each pending dfrag:
While sends succeed:
Send the dfrag data with mptcp_sendmsg_frag()
Update already_sent, snd_nxt, snd_burst
Update msk->first_pending
Break if required by msk->snd_burst / etc
Move the duplicate code from __mptcp_push_pending() and
__mptcp_subflow_push_pending() into a new helper function, named
__subflow_push_pending(). Simplify __mptcp_push_pending() and
__mptcp_subflow_push_pending() by invoking this helper.
Also move the burst check conditions out of the function
mptcp_subflow_get_send(), check them in __subflow_push_pending() in
the inner "for each pending dfrag" loop.
Reviewed-by: Mat Martineau <martineau@...nel.org>
Signed-off-by: Geliang Tang <geliang.tang@...e.com>
Signed-off-by: Mat Martineau <martineau@...nel.org>
---
net/mptcp/protocol.c | 153 +++++++++++++++++++++++++++------------------------
1 file changed, 81 insertions(+), 72 deletions(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 6019a3cf1625..29c662ffcd05 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1386,14 +1386,6 @@ static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
sk_stream_memory_free(msk->first) ? msk->first : NULL;
}
- /* re-use last subflow, if the burst allow that */
- if (msk->last_snd && msk->snd_burst > 0 &&
- sk_stream_memory_free(msk->last_snd) &&
- mptcp_subflow_active(mptcp_subflow_ctx(msk->last_snd))) {
- mptcp_set_timeout(sk);
- return msk->last_snd;
- }
-
/* pick the subflow with the lower wmem/wspace ratio */
for (i = 0; i < SSK_MODE_MAX; ++i) {
send_info[i].ssk = NULL;
@@ -1499,57 +1491,86 @@ void mptcp_check_and_set_pending(struct sock *sk)
mptcp_sk(sk)->push_pending |= BIT(MPTCP_PUSH_PENDING);
}
-void __mptcp_push_pending(struct sock *sk, unsigned int flags)
+static int __subflow_push_pending(struct sock *sk, struct sock *ssk,
+ struct mptcp_sendmsg_info *info)
{
- struct sock *prev_ssk = NULL, *ssk = NULL;
struct mptcp_sock *msk = mptcp_sk(sk);
- struct mptcp_sendmsg_info info = {
- .flags = flags,
- };
- bool do_check_data_fin = false;
struct mptcp_data_frag *dfrag;
- int len;
+ int len, copied = 0, err = 0;
while ((dfrag = mptcp_send_head(sk))) {
- info.sent = dfrag->already_sent;
- info.limit = dfrag->data_len;
+ info->sent = dfrag->already_sent;
+ info->limit = dfrag->data_len;
len = dfrag->data_len - dfrag->already_sent;
while (len > 0) {
int ret = 0;
- prev_ssk = ssk;
- ssk = mptcp_subflow_get_send(msk);
-
- /* First check. If the ssk has changed since
- * the last round, release prev_ssk
- */
- if (ssk != prev_ssk && prev_ssk)
- mptcp_push_release(prev_ssk, &info);
- if (!ssk)
- goto out;
-
- /* Need to lock the new subflow only if different
- * from the previous one, otherwise we are still
- * helding the relevant lock
- */
- if (ssk != prev_ssk)
- lock_sock(ssk);
-
- ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info);
+ ret = mptcp_sendmsg_frag(sk, ssk, dfrag, info);
if (ret <= 0) {
- if (ret == -EAGAIN)
- continue;
- mptcp_push_release(ssk, &info);
+ err = copied ? : ret;
goto out;
}
- do_check_data_fin = true;
- info.sent += ret;
+ info->sent += ret;
+ copied += ret;
len -= ret;
mptcp_update_post_push(msk, dfrag, ret);
}
WRITE_ONCE(msk->first_pending, mptcp_send_next(sk));
+
+ if (msk->snd_burst <= 0 ||
+ !sk_stream_memory_free(ssk) ||
+ !mptcp_subflow_active(mptcp_subflow_ctx(ssk))) {
+ err = copied;
+ goto out;
+ }
+ mptcp_set_timeout(sk);
+ }
+ err = copied;
+
+out:
+ return err;
+}
+
+void __mptcp_push_pending(struct sock *sk, unsigned int flags)
+{
+ struct sock *prev_ssk = NULL, *ssk = NULL;
+ struct mptcp_sock *msk = mptcp_sk(sk);
+ struct mptcp_sendmsg_info info = {
+ .flags = flags,
+ };
+ bool do_check_data_fin = false;
+
+ while (mptcp_send_head(sk)) {
+ int ret = 0;
+
+ prev_ssk = ssk;
+ ssk = mptcp_subflow_get_send(msk);
+
+ /* First check. If the ssk has changed since
+ * the last round, release prev_ssk
+ */
+ if (ssk != prev_ssk && prev_ssk)
+ mptcp_push_release(prev_ssk, &info);
+ if (!ssk)
+ goto out;
+
+ /* Need to lock the new subflow only if different
+ * from the previous one, otherwise we are still
+ * helding the relevant lock
+ */
+ if (ssk != prev_ssk)
+ lock_sock(ssk);
+
+ ret = __subflow_push_pending(sk, ssk, &info);
+ if (ret <= 0) {
+ if (ret == -EAGAIN)
+ continue;
+ mptcp_push_release(ssk, &info);
+ goto out;
+ }
+ do_check_data_fin = true;
}
/* at this point we held the socket lock for the last subflow we used */
@@ -1570,42 +1591,30 @@ static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk, bool
struct mptcp_sendmsg_info info = {
.data_lock_held = true,
};
- struct mptcp_data_frag *dfrag;
struct sock *xmit_ssk;
- int len, copied = 0;
+ int copied = 0;
info.flags = 0;
- while ((dfrag = mptcp_send_head(sk))) {
- info.sent = dfrag->already_sent;
- info.limit = dfrag->data_len;
- len = dfrag->data_len - dfrag->already_sent;
- while (len > 0) {
- int ret = 0;
-
- /* check for a different subflow usage only after
- * spooling the first chunk of data
- */
- xmit_ssk = first ? ssk : mptcp_subflow_get_send(msk);
- if (!xmit_ssk)
- goto out;
- if (xmit_ssk != ssk) {
- mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk),
- MPTCP_DELEGATE_SEND);
- goto out;
- }
-
- ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info);
- if (ret <= 0)
- goto out;
+ while (mptcp_send_head(sk)) {
+ int ret = 0;
- info.sent += ret;
- copied += ret;
- len -= ret;
- first = false;
-
- mptcp_update_post_push(msk, dfrag, ret);
+ /* check for a different subflow usage only after
+ * spooling the first chunk of data
+ */
+ xmit_ssk = first ? ssk : mptcp_subflow_get_send(msk);
+ if (!xmit_ssk)
+ goto out;
+ if (xmit_ssk != ssk) {
+ mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk),
+ MPTCP_DELEGATE_SEND);
+ goto out;
}
- WRITE_ONCE(msk->first_pending, mptcp_send_next(sk));
+
+ ret = __subflow_push_pending(sk, ssk, &info);
+ first = false;
+ if (ret <= 0)
+ break;
+ copied += ret;
}
out:
--
2.41.0
Powered by blists - more mailing lists