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| author |   Eric Dumazet <edumazet@google.com> | 2016-10-31 13:32:55 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2016-10-31 20:59:58 -0400 |
| commit | bd68a2a854ad5a85f0c8d0a9c8048ca3f6391efb (patch) | |
| tree | 0cb804e92986b27471e99a0473f02f9d91b2a256 /include/net/sock.h | |
| parent | net: cris: make eth_v10.c explicitly non-modular (diff) | |
| download | linux-dev-bd68a2a854ad5a85f0c8d0a9c8048ca3f6391efb.tar.xz linux-dev-bd68a2a854ad5a85f0c8d0a9c8048ca3f6391efb.zip | |
net: set SK_MEM_QUANTUM to 4096
Systems with large pages (64KB pages for example) do not always have
huge quantity of memory.
A big SK_MEM_QUANTUM value leads to fewer interactions with the
global counters (like tcp_memory_allocated) but might trigger
memory pressure much faster, giving suboptimal TCP performance
since windows are lowered to ridiculous values.
Note that sysctl_mem units being in pages and in ABI, we also need
to change sk_prot_mem_limits() accordingly.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/sock.h')
| -rw-r--r-- | include/net/sock.h | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index f13ac87a8015..93331a1492db 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1162,11 +1162,6 @@ static inline void sk_enter_memory_pressure(struct sock *sk) sk->sk_prot->enter_memory_pressure(sk); } -static inline long sk_prot_mem_limits(const struct sock *sk, int index) -{ - return sk->sk_prot->sysctl_mem[index]; -} - static inline long sk_memory_allocated(const struct sock *sk) { @@ -1281,11 +1276,27 @@ int __sk_mem_schedule(struct sock *sk, int size, int kind); void __sk_mem_reduce_allocated(struct sock *sk, int amount); void __sk_mem_reclaim(struct sock *sk, int amount); -#define SK_MEM_QUANTUM ((int)PAGE_SIZE) +/* We used to have PAGE_SIZE here, but systems with 64KB pages + * do not necessarily have 16x time more memory than 4KB ones. + */ +#define SK_MEM_QUANTUM 4096 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM) #define SK_MEM_SEND 0 #define SK_MEM_RECV 1 +/* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */ +static inline long sk_prot_mem_limits(const struct sock *sk, int index) +{ + long val = sk->sk_prot->sysctl_mem[index]; + +#if PAGE_SIZE > SK_MEM_QUANTUM + val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT; +#elif PAGE_SIZE < SK_MEM_QUANTUM + val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT; +#endif + return val; +} + static inline int sk_mem_pages(int amt) { return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT; |