mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

tcp: adjust sndbuf according to sk_reserved_mem 

If user sets SO_RESERVE_MEM socket option, in order to fully utilize the
reserved memory in memory pressure state on the tx path, we modify the
logic in sk_stream_moderate_sndbuf() to set sk_sndbuf according to
available reserved memory, instead of MIN_SOCK_SNDBUF, and adjust it
when new data is acked.

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wei Wang 2021-09-29 10:25:12 -07:00 committed by David S. Miller
parent 2bb2f5fb21
commit ca057051cf
2 changed files with 13 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/net/sock.h
View File

@ -2378,6 +2378,7 @@ static inline void sk_stream_moderate_sndbuf(struct sock *sk)
return;
val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
val = max_t(u32, val, sk_unused_reserved_mem(sk));
WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
}

14
net/ipv4/tcp_input.c
View File

@ -5380,7 +5380,7 @@ static int tcp_prune_queue(struct sock *sk)
return -1;
}
static bool tcp_should_expand_sndbuf(const struct sock *sk)
static bool tcp_should_expand_sndbuf(struct sock *sk)
{
const struct tcp_sock *tp = tcp_sk(sk);
@ -5391,8 +5391,18 @@ static bool tcp_should_expand_sndbuf(const struct sock *sk)
return false;
/* If we are under global TCP memory pressure, do not expand. */
if (tcp_under_memory_pressure(sk))
if (tcp_under_memory_pressure(sk)) {
int unused_mem = sk_unused_reserved_mem(sk);
/* Adjust sndbuf according to reserved mem. But make sure
* it never goes below SOCK_MIN_SNDBUF.
* See sk_stream_moderate_sndbuf() for more details.
*/
if (unused_mem > SOCK_MIN_SNDBUF)
WRITE_ONCE(sk->sk_sndbuf, unused_mem);
return false;
}
/* If we are under soft global TCP memory pressure, do not expand. */
if (sk_memory_allocated(sk) >= sk_prot_mem_limits(sk, 0))