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[NET]: Define infrastructure to keep 'inuse' changes in an efficent SMP/NUMA way.

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"struct proto" currently uses an array stats[NR_CPUS] to track change on
'inuse' sockets per protocol.

If NR_CPUS is big, this means we use a big memory area for this.
Moreover, all this memory area is located on a single node on NUMA
machines, increasing memory pressure on the boot node.

In this patch, I tried to :

- Keep a fast !CONFIG_SMP implementation
- Keep a fast CONFIG_SMP implementation for often used protocols
(tcp,udp,raw,...)
- Introduce a NUMA efficient implementation

Some helper macros are defined in include/net/sock.h
These macros take into account CONFIG_SMP

If a "struct proto" is declared without using DEFINE_PROTO_INUSE /
REF_PROTO_INUSE
macros, it will automatically use a default implementation, using a
dynamically allocated percpu zone.
This default implementation will be NUMA efficient, but might use 32/64
bytes per possible cpu
because of current alloc_percpu() implementation.
However it still should be better than previous implementation based on
stats[NR_CPUS] field.

When a "struct proto" is changed to use the new macros, we use a single
static "int" percpu variable,
lowering the memory and cpu costs, still preserving NUMA efficiency.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2007-11-05 23:38:39 -08:00
committed by David S. Miller
parent 91781004b9
commit 286ab3d460
4 changed files with 112 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files
net/ipv4/proc.c
+4 -15
View File
@@ -46,17 +46,6 @@
#include <net/sock.h>
#include <net/raw.h>
static int fold_prot_inuse(struct proto *proto)
{
int res = 0;
int cpu;
for_each_possible_cpu(cpu)
res += proto->stats[cpu].inuse;
return res;
}
/*
* Report socket allocation statistics [mea@utu.fi]
*/
@@ -64,12 +53,12 @@ static int sockstat_seq_show(struct seq_file *seq, void *v)
{
socket_seq_show(seq);
seq_printf(seq, "TCP: inuse %d orphan %d tw %d alloc %d mem %d\n",
fold_prot_inuse(&tcp_prot), atomic_read(&tcp_orphan_count),
sock_prot_inuse(&tcp_prot), atomic_read(&tcp_orphan_count),
tcp_death_row.tw_count, atomic_read(&tcp_sockets_allocated),
atomic_read(&tcp_memory_allocated));
seq_printf(seq, "UDP: inuse %d\n", fold_prot_inuse(&udp_prot));
seq_printf(seq, "UDPLITE: inuse %d\n", fold_prot_inuse(&udplite_prot));
seq_printf(seq, "RAW: inuse %d\n", fold_prot_inuse(&raw_prot));
seq_printf(seq, "UDP: inuse %d\n", sock_prot_inuse(&udp_prot));
seq_printf(seq, "UDPLITE: inuse %d\n", sock_prot_inuse(&udplite_prot));
seq_printf(seq, "RAW: inuse %d\n", sock_prot_inuse(&raw_prot));
seq_printf(seq, "FRAG: inuse %d memory %d\n",
ip_frag_nqueues(), ip_frag_mem());
return 0;