[TCP]: Fix tcp_mem[] initialization.

Change tcp_mem initialization function.  The fraction of total memory
is now a continuous function of memory size, and independent of page
size.

Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
John Heffner 2007-03-16 15:04:03 -07:00 committed by David S. Miller
parent 3e6b3b2e34
commit 53cdcc04c1

View file

@ -2458,11 +2458,18 @@ void __init tcp_init(void)
sysctl_max_syn_backlog = 128;
}
/* Allow no more than 3/4 kernel memory (usually less) allocated to TCP */
sysctl_tcp_mem[0] = (1536 / sizeof (struct inet_bind_hashbucket)) << order;
sysctl_tcp_mem[1] = sysctl_tcp_mem[0] * 4 / 3;
/* Set the pressure threshold to be a fraction of global memory that
* is up to 1/2 at 256 MB, decreasing toward zero with the amount of
* memory, with a floor of 128 pages.
*/
limit = min(nr_all_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
limit = (limit * (nr_all_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
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;
/* Set per-socket limits to no more than 1/128 the pressure threshold */
limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7);
max_share = min(4UL*1024*1024, limit);