* [PATCH net-next v3 1/3] mptcp: never fetch fwd memory from the subflow
@ 2022-06-20 16:19 Paolo Abeni
2022-06-20 16:19 ` [PATCH net-next v3 2/3] mptcp: drop SK_RECLAIM_* macros Paolo Abeni
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Paolo Abeni @ 2022-06-20 16:19 UTC (permalink / raw)
To: mptcp
The memory accounting is broken in such exceptional code
path, and after commit 4890b686f408 ("net: keep sk->sk_forward_alloc
as small as possible") we can't find much help there.
Drop the broken code.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
This is possibly for net, but makes sense only on top of recent
net-next patches, so whatever ;)
---
net/mptcp/protocol.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 6d2aa41390e7..0d4b2c010da0 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -328,15 +328,10 @@ static bool mptcp_rmem_schedule(struct sock *sk, struct sock *ssk, int size)
amt = sk_mem_pages(size);
amount = amt << PAGE_SHIFT;
- msk->rmem_fwd_alloc += amount;
- if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV)) {
- if (ssk->sk_forward_alloc < amount) {
- msk->rmem_fwd_alloc -= amount;
- return false;
- }
+ if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV))
+ return false;
- ssk->sk_forward_alloc -= amount;
- }
+ msk->rmem_fwd_alloc += amount;
return true;
}
--
2.35.3
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH net-next v3 2/3] mptcp: drop SK_RECLAIM_* macros
2022-06-20 16:19 [PATCH net-next v3 1/3] mptcp: never fetch fwd memory from the subflow Paolo Abeni
@ 2022-06-20 16:19 ` Paolo Abeni
2022-06-20 20:38 ` Mat Martineau
2022-06-20 16:19 ` [PATCH net-next v3 3/3] mptcp: refine memory scheduling Paolo Abeni
2022-06-20 16:46 ` [PATCH net-next v3 1/3] mptcp: never fetch fwd memory from the subflow Paolo Abeni
2 siblings, 1 reply; 6+ messages in thread
From: Paolo Abeni @ 2022-06-20 16:19 UTC (permalink / raw)
To: mptcp
After commit 4890b686f408 ("net: keep sk->sk_forward_alloc as small as
possible"), the MPTCP protocol is the last SK_RECLAIM_CHUNK and
SK_RECLAIM_THRESHOLD users.
Update the MPTCP reclaim schema to match the core/TCP one and drop the
mentioned macros. This additionally clean the MPTCP code a bit.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
net/mptcp/protocol.c | 35 ++---------------------------------
1 file changed, 2 insertions(+), 33 deletions(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 0d4b2c010da0..b31bac33f87a 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -181,8 +181,8 @@ static void mptcp_rmem_uncharge(struct sock *sk, int size)
reclaimable = msk->rmem_fwd_alloc - sk_unused_reserved_mem(sk);
/* see sk_mem_uncharge() for the rationale behind the following schema */
- if (unlikely(reclaimable >= SK_RECLAIM_THRESHOLD))
- __mptcp_rmem_reclaim(sk, SK_RECLAIM_CHUNK);
+ if (unlikely(reclaimable >= PAGE_SIZE))
+ __mptcp_rmem_reclaim(sk, reclaimable);
}
static void mptcp_rfree(struct sk_buff *skb)
@@ -961,25 +961,6 @@ static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk,
df->data_seq + df->data_len == msk->write_seq;
}
-static void __mptcp_mem_reclaim_partial(struct sock *sk)
-{
- int reclaimable = mptcp_sk(sk)->rmem_fwd_alloc - sk_unused_reserved_mem(sk);
-
- lockdep_assert_held_once(&sk->sk_lock.slock);
-
- if (reclaimable > (int)PAGE_SIZE)
- __mptcp_rmem_reclaim(sk, reclaimable - 1);
-
- sk_mem_reclaim(sk);
-}
-
-static void mptcp_mem_reclaim_partial(struct sock *sk)
-{
- mptcp_data_lock(sk);
- __mptcp_mem_reclaim_partial(sk);
- mptcp_data_unlock(sk);
-}
-
static void dfrag_uncharge(struct sock *sk, int len)
{
sk_mem_uncharge(sk, len);
@@ -999,7 +980,6 @@ static void __mptcp_clean_una(struct sock *sk)
{
struct mptcp_sock *msk = mptcp_sk(sk);
struct mptcp_data_frag *dtmp, *dfrag;
- bool cleaned = false;
u64 snd_una;
/* on fallback we just need to ignore snd_una, as this is really
@@ -1022,7 +1002,6 @@ static void __mptcp_clean_una(struct sock *sk)
}
dfrag_clear(sk, dfrag);
- cleaned = true;
}
dfrag = mptcp_rtx_head(sk);
@@ -1044,7 +1023,6 @@ static void __mptcp_clean_una(struct sock *sk)
dfrag->already_sent -= delta;
dfrag_uncharge(sk, delta);
- cleaned = true;
}
/* all retransmitted data acked, recovery completed */
@@ -1052,9 +1030,6 @@ static void __mptcp_clean_una(struct sock *sk)
msk->recovery = false;
out:
- if (cleaned && tcp_under_memory_pressure(sk))
- __mptcp_mem_reclaim_partial(sk);
-
if (snd_una == READ_ONCE(msk->snd_nxt) &&
snd_una == READ_ONCE(msk->write_seq)) {
if (mptcp_timer_pending(sk) && !mptcp_data_fin_enabled(msk))
@@ -1206,12 +1181,6 @@ static struct sk_buff *mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, boo
{
gfp_t gfp = data_lock_held ? GFP_ATOMIC : sk->sk_allocation;
- if (unlikely(tcp_under_memory_pressure(sk))) {
- if (data_lock_held)
- __mptcp_mem_reclaim_partial(sk);
- else
- mptcp_mem_reclaim_partial(sk);
- }
return __mptcp_alloc_tx_skb(sk, ssk, gfp);
}
--
2.35.3
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH net-next v3 3/3] mptcp: refine memory scheduling
2022-06-20 16:19 [PATCH net-next v3 1/3] mptcp: never fetch fwd memory from the subflow Paolo Abeni
2022-06-20 16:19 ` [PATCH net-next v3 2/3] mptcp: drop SK_RECLAIM_* macros Paolo Abeni
@ 2022-06-20 16:19 ` Paolo Abeni
2022-06-20 20:32 ` Mat Martineau
2022-06-20 16:46 ` [PATCH net-next v3 1/3] mptcp: never fetch fwd memory from the subflow Paolo Abeni
2 siblings, 1 reply; 6+ messages in thread
From: Paolo Abeni @ 2022-06-20 16:19 UTC (permalink / raw)
To: mptcp
Similar to commit 7c80b038d23e ("net: fix sk_wmem_schedule() and
sk_rmem_schedule() errors"), let the MPTCP receive path schedule
exactly the required amount of memory.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
net/mptcp/protocol.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index b31bac33f87a..0e295b3bce54 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -326,6 +326,7 @@ static bool mptcp_rmem_schedule(struct sock *sk, struct sock *ssk, int size)
if (size < msk->rmem_fwd_alloc)
return true;
+ size -= msk->rmem_fwd_alloc;
amt = sk_mem_pages(size);
amount = amt << PAGE_SHIFT;
if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV))
--
2.35.3
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH net-next v3 1/3] mptcp: never fetch fwd memory from the subflow
2022-06-20 16:19 [PATCH net-next v3 1/3] mptcp: never fetch fwd memory from the subflow Paolo Abeni
2022-06-20 16:19 ` [PATCH net-next v3 2/3] mptcp: drop SK_RECLAIM_* macros Paolo Abeni
2022-06-20 16:19 ` [PATCH net-next v3 3/3] mptcp: refine memory scheduling Paolo Abeni
@ 2022-06-20 16:46 ` Paolo Abeni
2 siblings, 0 replies; 6+ messages in thread
From: Paolo Abeni @ 2022-06-20 16:46 UTC (permalink / raw)
To: mptcp
On Mon, 2022-06-20 at 18:19 +0200, Paolo Abeni wrote:
> The memory accounting is broken in such exceptional code
> path, and after commit 4890b686f408 ("net: keep sk->sk_forward_alloc
> as small as possible") we can't find much help there.
>
> Drop the broken code.
>
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This is actually a "v2" ;)
The only change is the new patch 3/3 - I even kept the obsolete comment
after the commit message in patch 1/3 :)
/P
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net-next v3 3/3] mptcp: refine memory scheduling
2022-06-20 16:19 ` [PATCH net-next v3 3/3] mptcp: refine memory scheduling Paolo Abeni
@ 2022-06-20 20:32 ` Mat Martineau
0 siblings, 0 replies; 6+ messages in thread
From: Mat Martineau @ 2022-06-20 20:32 UTC (permalink / raw)
To: Paolo Abeni; +Cc: mptcp
On Mon, 20 Jun 2022, Paolo Abeni wrote:
> Similar to commit 7c80b038d23e ("net: fix sk_wmem_schedule() and
> sk_rmem_schedule() errors"), let the MPTCP receive path schedule
> exactly the required amount of memory.
>
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
> net/mptcp/protocol.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
> index b31bac33f87a..0e295b3bce54 100644
> --- a/net/mptcp/protocol.c
> +++ b/net/mptcp/protocol.c
> @@ -326,6 +326,7 @@ static bool mptcp_rmem_schedule(struct sock *sk, struct sock *ssk, int size)
> if (size < msk->rmem_fwd_alloc)
With the change below, also would be good to change the above line to:
if (size <= msk->rmem_fwd_alloc)
so there's no attempt to allocate 0 new pages.
> return true;
>
> + size -= msk->rmem_fwd_alloc;
> amt = sk_mem_pages(size);
> amount = amt << PAGE_SHIFT;
> if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV))
> --
> 2.35.3
>
>
>
--
Mat Martineau
Intel
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net-next v3 2/3] mptcp: drop SK_RECLAIM_* macros
2022-06-20 16:19 ` [PATCH net-next v3 2/3] mptcp: drop SK_RECLAIM_* macros Paolo Abeni
@ 2022-06-20 20:38 ` Mat Martineau
0 siblings, 0 replies; 6+ messages in thread
From: Mat Martineau @ 2022-06-20 20:38 UTC (permalink / raw)
To: Paolo Abeni; +Cc: mptcp
On Mon, 20 Jun 2022, Paolo Abeni wrote:
> After commit 4890b686f408 ("net: keep sk->sk_forward_alloc as small as
> possible"), the MPTCP protocol is the last SK_RECLAIM_CHUNK and
> SK_RECLAIM_THRESHOLD users.
>
> Update the MPTCP reclaim schema to match the core/TCP one and drop the
> mentioned macros. This additionally clean the MPTCP code a bit.
>
Please also add one more patch to the series that deletes SK_RECLAIM_*
from include/net/sock.h
- Mat
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
> net/mptcp/protocol.c | 35 ++---------------------------------
> 1 file changed, 2 insertions(+), 33 deletions(-)
>
> diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
> index 0d4b2c010da0..b31bac33f87a 100644
> --- a/net/mptcp/protocol.c
> +++ b/net/mptcp/protocol.c
> @@ -181,8 +181,8 @@ static void mptcp_rmem_uncharge(struct sock *sk, int size)
> reclaimable = msk->rmem_fwd_alloc - sk_unused_reserved_mem(sk);
>
> /* see sk_mem_uncharge() for the rationale behind the following schema */
> - if (unlikely(reclaimable >= SK_RECLAIM_THRESHOLD))
> - __mptcp_rmem_reclaim(sk, SK_RECLAIM_CHUNK);
> + if (unlikely(reclaimable >= PAGE_SIZE))
> + __mptcp_rmem_reclaim(sk, reclaimable);
> }
>
> static void mptcp_rfree(struct sk_buff *skb)
> @@ -961,25 +961,6 @@ static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk,
> df->data_seq + df->data_len == msk->write_seq;
> }
>
> -static void __mptcp_mem_reclaim_partial(struct sock *sk)
> -{
> - int reclaimable = mptcp_sk(sk)->rmem_fwd_alloc - sk_unused_reserved_mem(sk);
> -
> - lockdep_assert_held_once(&sk->sk_lock.slock);
> -
> - if (reclaimable > (int)PAGE_SIZE)
> - __mptcp_rmem_reclaim(sk, reclaimable - 1);
> -
> - sk_mem_reclaim(sk);
> -}
> -
> -static void mptcp_mem_reclaim_partial(struct sock *sk)
> -{
> - mptcp_data_lock(sk);
> - __mptcp_mem_reclaim_partial(sk);
> - mptcp_data_unlock(sk);
> -}
> -
> static void dfrag_uncharge(struct sock *sk, int len)
> {
> sk_mem_uncharge(sk, len);
> @@ -999,7 +980,6 @@ static void __mptcp_clean_una(struct sock *sk)
> {
> struct mptcp_sock *msk = mptcp_sk(sk);
> struct mptcp_data_frag *dtmp, *dfrag;
> - bool cleaned = false;
> u64 snd_una;
>
> /* on fallback we just need to ignore snd_una, as this is really
> @@ -1022,7 +1002,6 @@ static void __mptcp_clean_una(struct sock *sk)
> }
>
> dfrag_clear(sk, dfrag);
> - cleaned = true;
> }
>
> dfrag = mptcp_rtx_head(sk);
> @@ -1044,7 +1023,6 @@ static void __mptcp_clean_una(struct sock *sk)
> dfrag->already_sent -= delta;
>
> dfrag_uncharge(sk, delta);
> - cleaned = true;
> }
>
> /* all retransmitted data acked, recovery completed */
> @@ -1052,9 +1030,6 @@ static void __mptcp_clean_una(struct sock *sk)
> msk->recovery = false;
>
> out:
> - if (cleaned && tcp_under_memory_pressure(sk))
> - __mptcp_mem_reclaim_partial(sk);
> -
> if (snd_una == READ_ONCE(msk->snd_nxt) &&
> snd_una == READ_ONCE(msk->write_seq)) {
> if (mptcp_timer_pending(sk) && !mptcp_data_fin_enabled(msk))
> @@ -1206,12 +1181,6 @@ static struct sk_buff *mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, boo
> {
> gfp_t gfp = data_lock_held ? GFP_ATOMIC : sk->sk_allocation;
>
> - if (unlikely(tcp_under_memory_pressure(sk))) {
> - if (data_lock_held)
> - __mptcp_mem_reclaim_partial(sk);
> - else
> - mptcp_mem_reclaim_partial(sk);
> - }
> return __mptcp_alloc_tx_skb(sk, ssk, gfp);
> }
>
> --
> 2.35.3
>
>
>
--
Mat Martineau
Intel
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-06-20 20:38 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-06-20 16:19 [PATCH net-next v3 1/3] mptcp: never fetch fwd memory from the subflow Paolo Abeni
2022-06-20 16:19 ` [PATCH net-next v3 2/3] mptcp: drop SK_RECLAIM_* macros Paolo Abeni
2022-06-20 20:38 ` Mat Martineau
2022-06-20 16:19 ` [PATCH net-next v3 3/3] mptcp: refine memory scheduling Paolo Abeni
2022-06-20 20:32 ` Mat Martineau
2022-06-20 16:46 ` [PATCH net-next v3 1/3] mptcp: never fetch fwd memory from the subflow Paolo Abeni
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