From: Eric Dumazet <eduma...@google.com> 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, thus suboptimal TCP performance since windows are lowered to ridiculous values. Signed-off-by: Eric Dumazet <eduma...@google.com> --- include/net/sock.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/include/net/sock.h b/include/net/sock.h index f13ac87a8015cb18c5d3fe5fdcf2d6a0592428f4..d3409bb514e7f08b9cf183b7405d876bec18d732 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1281,7 +1281,10 @@ 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
