| 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
| ||
|
Message-Id: <20210621225438.10777-2-mathew.j.martineau@linux.intel.com>
Date: Mon, 21 Jun 2021 15:54:33 -0700
From: Mat Martineau <mathew.j.martineau@...ux.intel.com>
To: netdev@...r.kernel.org
Cc: Paolo Abeni <pabeni@...hat.com>, davem@...emloft.net,
kuba@...nel.org, matthieu.baerts@...sares.net,
mptcp@...ts.linux.dev,
Mat Martineau <mathew.j.martineau@...ux.intel.com>
Subject: [PATCH net-next 1/6] mptcp: drop tx skb cache
From: Paolo Abeni <pabeni@...hat.com>
The mentioned cache was introduced to reduce the number of skb
allocation in atomic context, but the required complexity is
excessive.
This change remove the mentioned cache.
Signed-off-by: Paolo Abeni <pabeni@...hat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@...ux.intel.com>
---
net/mptcp/protocol.c | 89 ++------------------------------------------
net/mptcp/protocol.h | 2 -
2 files changed, 4 insertions(+), 87 deletions(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index b5f2f504b85b..77c90d6f04df 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -902,22 +902,14 @@ static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk,
df->data_seq + df->data_len == msk->write_seq;
}
-static int mptcp_wmem_with_overhead(struct sock *sk, int size)
+static int mptcp_wmem_with_overhead(int size)
{
- struct mptcp_sock *msk = mptcp_sk(sk);
- int ret, skbs;
-
- ret = size + ((sizeof(struct mptcp_data_frag) * size) >> PAGE_SHIFT);
- skbs = (msk->tx_pending_data + size) / msk->size_goal_cache;
- if (skbs < msk->skb_tx_cache.qlen)
- return ret;
-
- return ret + (skbs - msk->skb_tx_cache.qlen) * SKB_TRUESIZE(MAX_TCP_HEADER);
+ return size + ((sizeof(struct mptcp_data_frag) * size) >> PAGE_SHIFT);
}
static void __mptcp_wmem_reserve(struct sock *sk, int size)
{
- int amount = mptcp_wmem_with_overhead(sk, size);
+ int amount = mptcp_wmem_with_overhead(size);
struct mptcp_sock *msk = mptcp_sk(sk);
WARN_ON_ONCE(msk->wmem_reserved);
@@ -1212,49 +1204,8 @@ static struct sk_buff *__mptcp_do_alloc_tx_skb(struct sock *sk, gfp_t gfp)
return NULL;
}
-static bool mptcp_tx_cache_refill(struct sock *sk, int size,
- struct sk_buff_head *skbs, int *total_ts)
-{
- struct mptcp_sock *msk = mptcp_sk(sk);
- struct sk_buff *skb;
- int space_needed;
-
- if (unlikely(tcp_under_memory_pressure(sk))) {
- mptcp_mem_reclaim_partial(sk);
-
- /* under pressure pre-allocate at most a single skb */
- if (msk->skb_tx_cache.qlen)
- return true;
- space_needed = msk->size_goal_cache;
- } else {
- space_needed = msk->tx_pending_data + size -
- msk->skb_tx_cache.qlen * msk->size_goal_cache;
- }
-
- while (space_needed > 0) {
- skb = __mptcp_do_alloc_tx_skb(sk, sk->sk_allocation);
- if (unlikely(!skb)) {
- /* under memory pressure, try to pass the caller a
- * single skb to allow forward progress
- */
- while (skbs->qlen > 1) {
- skb = __skb_dequeue_tail(skbs);
- *total_ts -= skb->truesize;
- __kfree_skb(skb);
- }
- return skbs->qlen > 0;
- }
-
- *total_ts += skb->truesize;
- __skb_queue_tail(skbs, skb);
- space_needed -= msk->size_goal_cache;
- }
- return true;
-}
-
static bool __mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, gfp_t gfp)
{
- struct mptcp_sock *msk = mptcp_sk(sk);
struct sk_buff *skb;
if (ssk->sk_tx_skb_cache) {
@@ -1265,22 +1216,6 @@ static bool __mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, gfp_t gfp)
return true;
}
- skb = skb_peek(&msk->skb_tx_cache);
- if (skb) {
- if (likely(sk_wmem_schedule(ssk, skb->truesize))) {
- skb = __skb_dequeue(&msk->skb_tx_cache);
- if (WARN_ON_ONCE(!skb))
- return false;
-
- mptcp_wmem_uncharge(sk, skb->truesize);
- ssk->sk_tx_skb_cache = skb;
- return true;
- }
-
- /* over memory limit, no point to try to allocate a new skb */
- return false;
- }
-
skb = __mptcp_do_alloc_tx_skb(sk, gfp);
if (!skb)
return false;
@@ -1296,7 +1231,6 @@ static bool __mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, gfp_t gfp)
static bool mptcp_must_reclaim_memory(struct sock *sk, struct sock *ssk)
{
return !ssk->sk_tx_skb_cache &&
- !skb_peek(&mptcp_sk(sk)->skb_tx_cache) &&
tcp_under_memory_pressure(sk);
}
@@ -1339,7 +1273,6 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
/* compute send limit */
info->mss_now = tcp_send_mss(ssk, &info->size_goal, info->flags);
avail_size = info->size_goal;
- msk->size_goal_cache = info->size_goal;
skb = tcp_write_queue_tail(ssk);
if (skb) {
/* Limit the write to the size available in the
@@ -1688,7 +1621,6 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
while (msg_data_left(msg)) {
int total_ts, frag_truesize = 0;
struct mptcp_data_frag *dfrag;
- struct sk_buff_head skbs;
bool dfrag_collapsed;
size_t psize, offset;
@@ -1721,16 +1653,10 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
psize = pfrag->size - offset;
psize = min_t(size_t, psize, msg_data_left(msg));
total_ts = psize + frag_truesize;
- __skb_queue_head_init(&skbs);
- if (!mptcp_tx_cache_refill(sk, psize, &skbs, &total_ts))
- goto wait_for_memory;
- if (!mptcp_wmem_alloc(sk, total_ts)) {
- __skb_queue_purge(&skbs);
+ if (!mptcp_wmem_alloc(sk, total_ts))
goto wait_for_memory;
- }
- skb_queue_splice_tail(&skbs, &msk->skb_tx_cache);
if (copy_page_from_iter(dfrag->page, offset, psize,
&msg->msg_iter) != psize) {
mptcp_wmem_uncharge(sk, psize + frag_truesize);
@@ -2462,13 +2388,11 @@ static int __mptcp_init_sock(struct sock *sk)
INIT_LIST_HEAD(&msk->rtx_queue);
INIT_WORK(&msk->work, mptcp_worker);
__skb_queue_head_init(&msk->receive_queue);
- __skb_queue_head_init(&msk->skb_tx_cache);
msk->out_of_order_queue = RB_ROOT;
msk->first_pending = NULL;
msk->wmem_reserved = 0;
msk->rmem_released = 0;
msk->tx_pending_data = 0;
- msk->size_goal_cache = TCP_BASE_MSS;
msk->ack_hint = NULL;
msk->first = NULL;
@@ -2525,15 +2449,10 @@ static void __mptcp_clear_xmit(struct sock *sk)
{
struct mptcp_sock *msk = mptcp_sk(sk);
struct mptcp_data_frag *dtmp, *dfrag;
- struct sk_buff *skb;
WRITE_ONCE(msk->first_pending, NULL);
list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list)
dfrag_clear(sk, dfrag);
- while ((skb = __skb_dequeue(&msk->skb_tx_cache)) != NULL) {
- sk->sk_forward_alloc += skb->truesize;
- kfree_skb(skb);
- }
}
static void mptcp_cancel_work(struct sock *sk)
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 160d716ebc2b..160c2ab09f19 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -245,9 +245,7 @@ struct mptcp_sock {
struct sk_buff *ooo_last_skb;
struct rb_root out_of_order_queue;
struct sk_buff_head receive_queue;
- struct sk_buff_head skb_tx_cache; /* this is wmem accounted */
int tx_pending_data;
- int size_goal_cache;
struct list_head conn_list;
struct list_head rtx_queue;
struct mptcp_data_frag *first_pending;
--
2.32.0
Powered by blists - more mailing lists