Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b66e91cc authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: halves tcp_mem[] limits 



Allowing tcp to use ~19% of physical memory is way too much,
and allowed bugs to be hidden. Add to this that some drivers use a full
page per incoming frame, so real cost can be twice the advertized one.

Reduce tcp_mem by 50 % as a first step to sanity.

tcp_mem[0,1,2] defaults are now 4.68%, 6.25%, 9.37% of physical memory.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 76dfa608

net/ipv4/tcp.c

+5 −4
Original line number Diff line number Diff line
@@ -3068,11 +3068,12 @@ __setup("thash_entries=", set_thash_entries); 


static void __init tcp_init_mem(void)

{

	unsigned long limit = nr_free_buffer_pages() / 8;

	unsigned long limit = nr_free_buffer_pages() / 16;



	limit = max(limit, 128UL);

	sysctl_tcp_mem[0] = limit / 4 * 3;

	sysctl_tcp_mem[1] = limit;

	sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;

	sysctl_tcp_mem[0] = limit / 4 * 3;		/* 4.68 % */

	sysctl_tcp_mem[1] = limit;			/* 6.25 % */

	sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;	/* 9.37 % */

}



void __init tcp_init(void)