From: Mike Anderson <andmike@xxxxxxxxxx>
This patch adds mempool support to dm-netlink.
Signed-off-by: Mike Anderson <andmike@xxxxxxxxxx>
---
The mempool support was originally derived from:
drivers/scsi/scsi_transport_iscsi.c.
drivers/md/dm-netlink.c | 152 ++++++++++++++++++++++++++++++++++++++++++------
drivers/md/dm-netlink.h | 1
2 files changed, 134 insertions(+), 19 deletions(-)
Index: linux-2.6-patched/drivers/md/dm-netlink.c
===================================================================
--- linux-2.6-patched.orig/drivers/md/dm-netlink.c 2007-01-09 01:12:02.000000000 -0800
+++ linux-2.6-patched/drivers/md/dm-netlink.c 2007-01-09 01:12:12.000000000 -0800
@@ -17,6 +17,8 @@
*
* Copyright IBM Corporation, 2005, 2006
* Author: Mike Anderson <andmike@xxxxxxxxxx>
+ *
+ * skb mempool derived from drivers/scsi/scsi_transport_iscsi.c
*/
#include <linux/module.h>
#include <linux/mempool.h>
@@ -27,56 +29,164 @@
#include <net/netlink.h>
#include "dm.h"
-#define EVENT_SKB_SIZE NLMSG_GOODSIZE
+#define EVENT_SKB_SIZE NLMSG_SPACE(128)
+#define MIN_EVENT_SKBS 16
+#define HIWAT_EVENT_SKBS 32
struct dm_event_cache {
struct kmem_cache *cache;
unsigned skb_size;
+ unsigned hiwat;
+ mempool_t *pool;
+ spinlock_t used_list_lock;
+ struct list_head used_list;
};
static struct dm_event_cache dme_cache;
-static int dme_cache_init(struct dm_event_cache *dc, unsigned skb_size)
+static void* mp_alloc_dm_event(gfp_t gfp_mask, void *pool_data)
+{
+ struct dm_event *evt;
+ struct dm_event_cache *dc = pool_data;
+
+ evt = kmem_cache_alloc(dc->cache, gfp_mask);
+ if (!evt)
+ goto out;
+
+ evt->skb = alloc_skb(dc->skb_size, gfp_mask);
+ if (!evt->skb)
+ goto cache_out;
+ return evt;
+
+cache_out:
+ kmem_cache_free(dc->cache, evt);
+out:
+ return NULL;
+}
+
+static void mp_free_dm_event(void *element, void *pool_data)
+{
+ struct dm_event *evt = element;
+ struct dm_event_cache *dc = pool_data;
+
+ kfree_skb(evt->skb);
+ kmem_cache_free(dc->cache, evt);
+}
+
+static int dme_cache_init(struct dm_event_cache *dc, unsigned skb_size,
+ unsigned min_nr, unsigned hiwat)
{
dc->skb_size = skb_size;
+ dc->hiwat = hiwat;
+ spin_lock_init(&dc->used_list_lock);
+ INIT_LIST_HEAD(&dc->used_list);
dc->cache = kmem_cache_create("dm_events",
sizeof(struct dm_event), 0, 0, NULL, NULL);
if (!dc->cache)
- return -ENOMEM;
+ goto cache_err_out;
+
+ dc->pool = mempool_create(min_nr, mp_alloc_dm_event,
+ mp_free_dm_event, dc);
+ if (!dc->pool)
+ goto mempool_err_out;
return 0;
+
+mempool_err_out:
+ kmem_cache_destroy(dc->cache);
+cache_err_out:
+ return -ENOMEM;
}
static void dme_cache_destroy(struct dm_event_cache *dc)
{
+ mempool_destroy(dc->pool);
kmem_cache_destroy(dc->cache);
}
+static void __dme_cache_event_put(struct dm_event *evt)
+{
+ struct dm_event_cache *dc = evt->cdata;
+ struct sk_buff *skb = evt->skb;
+
+ if (!skb_shared(skb)) {
+ list_del(&evt->used_list);
+ skb_orphan(skb);
+
+ /* Init in case sent to pool */
+ skb->len = 0;
+ skb->tail = skb->head;
+
+ mempool_free(evt, dc->pool);
+ }
+}
+
static void dme_cache_event_put(struct dm_event *evt)
{
struct dm_event_cache *dc = evt->cdata;
- kmem_cache_free(dc->cache, evt);
+ unsigned long flags;
+
+ spin_lock_irqsave(&dc->used_list_lock, flags);
+ __dme_cache_event_put(evt);
+ spin_unlock_irqrestore(&dc->used_list_lock, flags);
+}
+
+static void mp_cleanup_evt_pid(int pid, struct dm_event *evt)
+{
+ struct sk_buff *skb = evt->skb;
+ struct nlmsghdr *nlh;
+
+ if (skb->sk) {
+ nlh = (struct nlmsghdr *)skb->data;
+ if (nlh->nlmsg_pid == pid) {
+ if (skb->next && skb->sk)
+ skb_unlink(skb, &skb->sk->sk_receive_queue);
+ atomic_set(&skb->users, 1);
+ __dme_cache_event_put(evt);
+ }
+ }
+}
+
+static void mp_complete(struct dm_event_cache *dc, int release_pid)
+{
+ unsigned long flags;
+ struct dm_event *evt, *n;
+
+ spin_lock_irqsave(&dc->used_list_lock, flags);
+ if (!list_empty(&dc->used_list)) {
+ list_for_each_entry_safe(evt, n, &dc->used_list, used_list) {
+ if (release_pid) {
+ mp_cleanup_evt_pid(release_pid, evt);
+ } else {
+ __dme_cache_event_put(evt);
+ }
+ }
+ }
+ spin_unlock_irqrestore(&dc->used_list_lock, flags);
}
static struct dm_event* dme_cache_event_get(struct dm_event_cache *dc)
{
+ unsigned long flags;
struct dm_event *evt;
- evt = kmem_cache_alloc(dc->cache, GFP_ATOMIC);
- if (evt) {
- evt->cdata = dc;
- evt->skb = alloc_skb(dc->skb_size, GFP_ATOMIC);
- if (!evt->skb)
- goto cache_out;
- }
+ /* Check for ones we can complete before we alloc */
+ mp_complete(dc, 0);
- return evt;
+ evt = mempool_alloc(dc->pool, GFP_ATOMIC);
+ if (!evt)
+ return NULL;
+
+ evt->cdata = dc;
+ skb_get(evt->skb);
+ INIT_LIST_HEAD(&evt->used_list);
+ spin_lock_irqsave(&dc->used_list_lock, flags);
+ list_add(&evt->used_list, &dc->used_list);
+ spin_unlock_irqrestore(&dc->used_list_lock, flags);
-cache_out:
- dme_cache_event_put(evt);
- return NULL;
+ return evt;
}
static struct sock *dm_netlink_sock;
@@ -128,7 +238,8 @@
nla_put_failure:
printk(KERN_ERR "%s: nla_put_failure\n", __FUNCTION__);
- nlmsg_free(evt->skb);
+ /* Set skb users so mp_complete can free */
+ atomic_set(&evt->skb->users, 1);
dme_cache_event_put(evt);
out:
return ERR_PTR(err);
@@ -167,9 +278,10 @@
nla_put_failure:
printk(KERN_ERR "%s: nla_put_failure\n", __FUNCTION__);
no_pid:
- nlmsg_free(evt->skb);
-out:
+ /* Set skb users so mp_complete can free */
+ atomic_set(&evt->skb->users, 1);
dme_cache_event_put(evt);
+out:
return;
}
EXPORT_SYMBOL(dm_send_event);
@@ -246,6 +358,7 @@
if (event == NETLINK_URELEASE &&
n->protocol == NETLINK_DM && n->pid) {
if ( n->pid == dm_netlink_daemon_pid ) {
+ mp_complete(&dme_cache, dm_netlink_daemon_pid);
dm_netlink_daemon_pid = 0;
}
}
@@ -273,7 +386,8 @@
err = -ENOBUFS;
goto notifier_out;
}
- err = dme_cache_init(&dme_cache, EVENT_SKB_SIZE);
+ err = dme_cache_init(&dme_cache, EVENT_SKB_SIZE, MIN_EVENT_SKBS,
+ HIWAT_EVENT_SKBS);
if (err)
goto socket_out;
Index: linux-2.6-patched/drivers/md/dm-netlink.h
===================================================================
--- linux-2.6-patched.orig/drivers/md/dm-netlink.h 2007-01-09 01:12:02.000000000 -0800
+++ linux-2.6-patched/drivers/md/dm-netlink.h 2007-01-09 01:12:12.000000000 -0800
@@ -27,6 +27,7 @@
void *cdata;
struct sk_buff *skb;
struct list_head elist;
+ struct list_head used_list;
};
#ifdef CONFIG_DM_NETLINK_EVENT
--
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