tcp: calculate tcp_mem based on low memory instead of all memory
The tcp_mem array which contains limits on the total amount of memory
used by TCP sockets is calculated based on nr_all_pages. On a 32 bits
x86 system, we should base this on the number of lowmem pages.
Signed-off-by: Miquel van Smoorenburg <miquels@cistron.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index fc54a48..850825d 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -260,6 +260,8 @@
#include <linux/socket.h>
#include <linux/random.h>
#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/swap.h>
#include <linux/cache.h>
#include <linux/err.h>
#include <linux/crypto.h>
@@ -2620,7 +2622,7 @@
void __init tcp_init(void)
{
struct sk_buff *skb = NULL;
- unsigned long limit;
+ unsigned long nr_pages, limit;
int order, i, max_share;
BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
@@ -2689,8 +2691,9 @@
* 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);
+ nr_pages = totalram_pages - totalhigh_pages;
+ limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
+ limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
limit = max(limit, 128UL);
sysctl_tcp_mem[0] = limit / 4 * 3;
sysctl_tcp_mem[1] = limit;