[ovs-dev] [netlink 09/16] datapath: Always use GFP_ATOMIC to execute actions.
Ben Pfaff
blp at nicira.com
Fri Sep 10 22:55:09 UTC 2010
These functions run 99% of the time in atomic context and the benefit of
passing along the 'gfp' argument for the other 1% doesn't seem to outweigh
the cost.
Suggested-by: Stephen Hemminger <shemminger at vyatta.com>
Signed-off-by: Ben Pfaff <blp at nicira.com>
---
datapath/actions.c | 65 ++++++++++++++++++++++----------------------------
datapath/actions.h | 4 +--
datapath/datapath.c | 5 +--
datapath/flow.h | 1 -
4 files changed, 32 insertions(+), 43 deletions(-)
diff --git a/datapath/actions.c b/datapath/actions.c
index 961a0dc..5ec7061 100644
--- a/datapath/actions.c
+++ b/datapath/actions.c
@@ -25,13 +25,13 @@
#include "openvswitch/datapath-protocol.h"
#include "vport.h"
-static struct sk_buff *make_writable(struct sk_buff *skb, unsigned min_headroom, gfp_t gfp)
+static struct sk_buff *make_writable(struct sk_buff *skb, unsigned min_headroom)
{
if (skb_cloned(skb)) {
struct sk_buff *nskb;
unsigned headroom = max(min_headroom, skb_headroom(skb));
- nskb = skb_copy_expand(skb, headroom, skb_tailroom(skb), gfp);
+ nskb = skb_copy_expand(skb, headroom, skb_tailroom(skb), GFP_ATOMIC);
if (nskb) {
set_skb_csum_bits(skb, nskb);
kfree_skb(skb);
@@ -72,13 +72,12 @@ static struct sk_buff *vlan_pull_tag(struct sk_buff *skb)
static struct sk_buff *modify_vlan_tci(struct datapath *dp, struct sk_buff *skb,
const struct odp_flow_key *key,
- const union odp_action *a, int n_actions,
- gfp_t gfp)
+ const union odp_action *a, int n_actions)
{
__be16 mask = a->dl_tci.mask;
__be16 tci = a->dl_tci.tci;
- skb = make_writable(skb, VLAN_HLEN, gfp);
+ skb = make_writable(skb, VLAN_HLEN);
if (!skb)
return ERR_PTR(-ENOMEM);
@@ -154,8 +153,7 @@ static struct sk_buff *modify_vlan_tci(struct datapath *dp, struct sk_buff *skb,
if (segs) {
err = execute_actions(dp, segs,
key, a + 1,
- n_actions - 1,
- gfp);
+ n_actions - 1);
}
if (unlikely(err)) {
@@ -193,19 +191,18 @@ static struct sk_buff *modify_vlan_tci(struct datapath *dp, struct sk_buff *skb,
return skb;
}
-static struct sk_buff *strip_vlan(struct sk_buff *skb, gfp_t gfp)
+static struct sk_buff *strip_vlan(struct sk_buff *skb)
{
- skb = make_writable(skb, 0, gfp);
+ skb = make_writable(skb, 0);
if (skb)
vlan_pull_tag(skb);
return skb;
}
static struct sk_buff *set_dl_addr(struct sk_buff *skb,
- const struct odp_action_dl_addr *a,
- gfp_t gfp)
+ const struct odp_action_dl_addr *a)
{
- skb = make_writable(skb, 0, gfp);
+ skb = make_writable(skb, 0);
if (skb) {
struct ethhdr *eh = eth_hdr(skb);
if (a->type == ODPAT_SET_DL_SRC)
@@ -257,8 +254,7 @@ static __sum16 *get_l4_checksum(struct sk_buff *skb, const struct odp_flow_key *
static struct sk_buff *set_nw_addr(struct sk_buff *skb,
const struct odp_flow_key *key,
- const struct odp_action_nw_addr *a,
- gfp_t gfp)
+ const struct odp_action_nw_addr *a)
{
struct iphdr *nh;
__sum16 *check;
@@ -267,7 +263,7 @@ static struct sk_buff *set_nw_addr(struct sk_buff *skb,
if (unlikely(!is_ip(skb, key)))
return skb;
- skb = make_writable(skb, 0, gfp);
+ skb = make_writable(skb, 0);
if (unlikely(!skb))
return NULL;
@@ -286,13 +282,12 @@ static struct sk_buff *set_nw_addr(struct sk_buff *skb,
static struct sk_buff *set_nw_tos(struct sk_buff *skb,
const struct odp_flow_key *key,
- const struct odp_action_nw_tos *a,
- gfp_t gfp)
+ const struct odp_action_nw_tos *a)
{
if (unlikely(!is_ip(skb, key)))
return skb;
- skb = make_writable(skb, 0, gfp);
+ skb = make_writable(skb, 0);
if (skb) {
struct iphdr *nh = ip_hdr(skb);
u8 *f = &nh->tos;
@@ -310,7 +305,7 @@ static struct sk_buff *set_nw_tos(struct sk_buff *skb,
static struct sk_buff *set_tp_port(struct sk_buff *skb,
const struct odp_flow_key *key,
- const struct odp_action_tp_port *a, gfp_t gfp)
+ const struct odp_action_tp_port *a)
{
struct udphdr *th;
__sum16 *check;
@@ -319,7 +314,7 @@ static struct sk_buff *set_tp_port(struct sk_buff *skb,
if (unlikely(!is_ip(skb, key)))
return skb;
- skb = make_writable(skb, 0, gfp);
+ skb = make_writable(skb, 0);
if (unlikely(!skb))
return NULL;
@@ -390,10 +385,9 @@ error:
kfree_skb(skb);
}
-static int output_control(struct datapath *dp, struct sk_buff *skb, u32 arg,
- gfp_t gfp)
+static int output_control(struct datapath *dp, struct sk_buff *skb, u32 arg)
{
- skb = skb_clone(skb, gfp);
+ skb = skb_clone(skb, GFP_ATOMIC);
if (!skb)
return -ENOMEM;
return dp_output_control(dp, skb, _ODPL_ACTION_NR, arg);
@@ -403,14 +397,14 @@ static int output_control(struct datapath *dp, struct sk_buff *skb, u32 arg,
* information about what happened to it. */
static void sflow_sample(struct datapath *dp, struct sk_buff *skb,
const union odp_action *a, int n_actions,
- gfp_t gfp, struct vport *vport)
+ struct vport *vport)
{
struct odp_sflow_sample_header *hdr;
unsigned int actlen = n_actions * sizeof(union odp_action);
unsigned int hdrlen = sizeof(struct odp_sflow_sample_header);
struct sk_buff *nskb;
- nskb = skb_copy_expand(skb, actlen + hdrlen, 0, gfp);
+ nskb = skb_copy_expand(skb, actlen + hdrlen, 0, GFP_ATOMIC);
if (!nskb)
return;
@@ -424,8 +418,7 @@ static void sflow_sample(struct datapath *dp, struct sk_buff *skb,
/* Execute a list of actions against 'skb'. */
int execute_actions(struct datapath *dp, struct sk_buff *skb,
const struct odp_flow_key *key,
- const union odp_action *a, int n_actions,
- gfp_t gfp)
+ const union odp_action *a, int n_actions)
{
/* Every output action needs a separate clone of 'skb', but the common
* case is just a single output action, so that doing a clone and
@@ -441,7 +434,7 @@ int execute_actions(struct datapath *dp, struct sk_buff *skb,
atomic_inc(&p->sflow_pool);
if (dp->sflow_probability == UINT_MAX ||
net_random() < dp->sflow_probability)
- sflow_sample(dp, skb, a, n_actions, gfp, p);
+ sflow_sample(dp, skb, a, n_actions, p);
}
}
@@ -449,7 +442,7 @@ int execute_actions(struct datapath *dp, struct sk_buff *skb,
for (; n_actions > 0; a++, n_actions--) {
if (prev_port != -1) {
- do_output(dp, skb_clone(skb, gfp), prev_port);
+ do_output(dp, skb_clone(skb, GFP_ATOMIC), prev_port);
prev_port = -1;
}
@@ -459,7 +452,7 @@ int execute_actions(struct datapath *dp, struct sk_buff *skb,
break;
case ODPAT_CONTROLLER:
- err = output_control(dp, skb, a->controller.arg, gfp);
+ err = output_control(dp, skb, a->controller.arg);
if (err) {
kfree_skb(skb);
return err;
@@ -471,32 +464,32 @@ int execute_actions(struct datapath *dp, struct sk_buff *skb,
break;
case ODPAT_SET_DL_TCI:
- skb = modify_vlan_tci(dp, skb, key, a, n_actions, gfp);
+ skb = modify_vlan_tci(dp, skb, key, a, n_actions);
if (IS_ERR(skb))
return PTR_ERR(skb);
break;
case ODPAT_STRIP_VLAN:
- skb = strip_vlan(skb, gfp);
+ skb = strip_vlan(skb);
break;
case ODPAT_SET_DL_SRC:
case ODPAT_SET_DL_DST:
- skb = set_dl_addr(skb, &a->dl_addr, gfp);
+ skb = set_dl_addr(skb, &a->dl_addr);
break;
case ODPAT_SET_NW_SRC:
case ODPAT_SET_NW_DST:
- skb = set_nw_addr(skb, key, &a->nw_addr, gfp);
+ skb = set_nw_addr(skb, key, &a->nw_addr);
break;
case ODPAT_SET_NW_TOS:
- skb = set_nw_tos(skb, key, &a->nw_tos, gfp);
+ skb = set_nw_tos(skb, key, &a->nw_tos);
break;
case ODPAT_SET_TP_SRC:
case ODPAT_SET_TP_DST:
- skb = set_tp_port(skb, key, &a->tp_port, gfp);
+ skb = set_tp_port(skb, key, &a->tp_port);
break;
case ODPAT_SET_PRIORITY:
diff --git a/datapath/actions.h b/datapath/actions.h
index da4f4bf..f2962a7 100644
--- a/datapath/actions.h
+++ b/datapath/actions.h
@@ -9,7 +9,6 @@
#ifndef ACTIONS_H
#define ACTIONS_H 1
-#include <linux/gfp.h>
#include <linux/skbuff.h>
#include <linux/version.h>
@@ -20,8 +19,7 @@ union odp_action;
int execute_actions(struct datapath *dp, struct sk_buff *skb,
const struct odp_flow_key *key,
- const union odp_action *, int n_actions,
- gfp_t gfp);
+ const union odp_action *, int n_actions);
static inline void set_skb_csum_bits(const struct sk_buff *old_skb,
struct sk_buff *new_skb)
diff --git a/datapath/datapath.c b/datapath/datapath.c
index 066308a..f0c6833 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -545,7 +545,7 @@ void dp_process_received_packet(struct vport *p, struct sk_buff *skb)
}
/* Execute actions. */
- execute_actions(dp, skb, &key, acts->actions, acts->n_actions, GFP_ATOMIC);
+ execute_actions(dp, skb, &key, acts->actions, acts->n_actions);
stats_counter_off = offsetof(struct dp_stats_percpu, n_hit);
/* Check whether sub-actions looped too much. */
@@ -1329,8 +1329,7 @@ static int do_execute(struct datapath *dp, const struct odp_execute *execute)
goto error_free_skb;
rcu_read_lock();
- err = execute_actions(dp, skb, &key, actions->actions,
- actions->n_actions, GFP_KERNEL);
+ err = execute_actions(dp, skb, &key, actions->actions, actions->n_actions);
rcu_read_unlock();
kfree(actions);
diff --git a/datapath/flow.h b/datapath/flow.h
index 80a5b66..a4f116e 100644
--- a/datapath/flow.h
+++ b/datapath/flow.h
@@ -13,7 +13,6 @@
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/rcupdate.h>
-#include <linux/gfp.h>
#include <linux/if_ether.h>
#include <linux/jiffies.h>
#include <linux/time.h>
--
1.7.1
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