[PATCH 08/10 v2] staging: ozwpan: Use slab cache for oz_elt_info allocation
From: Christoph Jaeger
Date: Fri Aug 08 2014 - 02:00:54 EST
Use a slab cache rather than rolling our own free list.
Signed-off-by: Christoph Jaeger <email@xxxxxxxxxxxxxxxxxxxx>
---
v2: Don't use likely()/unlikely().
drivers/staging/ozwpan/ozeltbuf.c | 68 ++-------------------------------------
drivers/staging/ozwpan/ozeltbuf.h | 5 ---
drivers/staging/ozwpan/ozpd.c | 2 --
drivers/staging/ozwpan/ozpd.h | 2 ++
drivers/staging/ozwpan/ozproto.c | 9 ++++++
drivers/staging/ozwpan/ozproto.h | 2 ++
6 files changed, 16 insertions(+), 72 deletions(-)
diff --git a/drivers/staging/ozwpan/ozeltbuf.c b/drivers/staging/ozwpan/ozeltbuf.c
index f6e6481..389ab1a 100644
--- a/drivers/staging/ozwpan/ozeltbuf.c
+++ b/drivers/staging/ozwpan/ozeltbuf.c
@@ -10,9 +10,6 @@
#include "ozeltbuf.h"
#include "ozpd.h"
-#define OZ_ELT_INFO_MAGIC_USED 0x35791057
-#define OZ_ELT_INFO_MAGIC_FREE 0x78940102
-
/*
* Context: softirq-serialized
*/
@@ -22,7 +19,6 @@ void oz_elt_buf_init(struct oz_elt_buf *buf)
INIT_LIST_HEAD(&buf->stream_list);
INIT_LIST_HEAD(&buf->order_list);
INIT_LIST_HEAD(&buf->isoc_list);
- buf->max_free_elts = 32;
spin_lock_init(&buf->lock);
}
@@ -49,14 +45,6 @@ void oz_elt_buf_term(struct oz_elt_buf *buf)
kfree(ei);
}
}
- /* Free any elelment in the pool. */
- while (buf->elt_pool) {
- struct oz_elt_info *ei =
- container_of(buf->elt_pool, struct oz_elt_info, link);
- buf->elt_pool = buf->elt_pool->next;
- kfree(ei);
- }
- buf->free_elts = 0;
}
/*
@@ -66,27 +54,8 @@ struct oz_elt_info *oz_elt_info_alloc(struct oz_elt_buf *buf)
{
struct oz_elt_info *ei;
- spin_lock_bh(&buf->lock);
- if (buf->free_elts && buf->elt_pool) {
- ei = container_of(buf->elt_pool, struct oz_elt_info, link);
- buf->elt_pool = ei->link.next;
- buf->free_elts--;
- spin_unlock_bh(&buf->lock);
- if (ei->magic != OZ_ELT_INFO_MAGIC_FREE) {
- oz_dbg(ON, "%s: ei with bad magic: 0x%x\n",
- __func__, ei->magic);
- }
- } else {
- spin_unlock_bh(&buf->lock);
- ei = kmalloc(sizeof(struct oz_elt_info), GFP_ATOMIC);
- }
+ ei = kmem_cache_zalloc(oz_elt_info_cache, GFP_ATOMIC);
if (ei) {
- ei->flags = 0;
- ei->app_id = 0;
- ei->callback = NULL;
- ei->context = 0;
- ei->stream = NULL;
- ei->magic = OZ_ELT_INFO_MAGIC_USED;
INIT_LIST_HEAD(&ei->link);
INIT_LIST_HEAD(&ei->link_order);
}
@@ -99,17 +68,8 @@ struct oz_elt_info *oz_elt_info_alloc(struct oz_elt_buf *buf)
*/
void oz_elt_info_free(struct oz_elt_buf *buf, struct oz_elt_info *ei)
{
- if (ei) {
- if (ei->magic == OZ_ELT_INFO_MAGIC_USED) {
- buf->free_elts++;
- ei->link.next = buf->elt_pool;
- buf->elt_pool = &ei->link;
- ei->magic = OZ_ELT_INFO_MAGIC_FREE;
- } else {
- oz_dbg(ON, "%s: bad magic ei: %p magic: 0x%x\n",
- __func__, ei, ei->magic);
- }
- }
+ if (ei)
+ kmem_cache_free(oz_elt_info_cache, ei);
}
/*------------------------------------------------------------------------------
@@ -313,25 +273,3 @@ int oz_are_elts_available(struct oz_elt_buf *buf)
{
return buf->order_list.next != &buf->order_list;
}
-
-void oz_trim_elt_pool(struct oz_elt_buf *buf)
-{
- struct list_head *free = NULL;
- struct list_head *e;
-
- spin_lock_bh(&buf->lock);
- while (buf->free_elts > buf->max_free_elts) {
- e = buf->elt_pool;
- buf->elt_pool = e->next;
- e->next = free;
- free = e;
- buf->free_elts--;
- }
- spin_unlock_bh(&buf->lock);
- while (free) {
- struct oz_elt_info *ei =
- container_of(free, struct oz_elt_info, link);
- free = free->next;
- kfree(ei);
- }
-}
diff --git a/drivers/staging/ozwpan/ozeltbuf.h b/drivers/staging/ozwpan/ozeltbuf.h
index 3846432..f09f5fe 100644
--- a/drivers/staging/ozwpan/ozeltbuf.h
+++ b/drivers/staging/ozwpan/ozeltbuf.h
@@ -34,7 +34,6 @@ struct oz_elt_info {
struct oz_elt_stream *stream;
u8 data[sizeof(struct oz_elt) + OZ_MAX_ELT_PAYLOAD];
int length;
- unsigned magic;
};
/* Flags values */
#define OZ_EI_F_MARKED 0x1
@@ -44,9 +43,6 @@ struct oz_elt_buf {
struct list_head stream_list;
struct list_head order_list;
struct list_head isoc_list;
- struct list_head *elt_pool;
- int free_elts;
- int max_free_elts;
u8 tx_seq_num[OZ_NB_APPS];
};
@@ -64,7 +60,6 @@ int oz_queue_elt_info(struct oz_elt_buf *buf, u8 isoc, u8 id,
int oz_select_elts_for_tx(struct oz_elt_buf *buf, u8 isoc, unsigned *len,
unsigned max_len, struct list_head *list);
int oz_are_elts_available(struct oz_elt_buf *buf);
-void oz_trim_elt_pool(struct oz_elt_buf *buf);
#endif /* _OZELTBUF_H */
diff --git a/drivers/staging/ozwpan/ozpd.c b/drivers/staging/ozwpan/ozpd.c
index 6c4b13f..c6fddb8 100644
--- a/drivers/staging/ozwpan/ozpd.c
+++ b/drivers/staging/ozwpan/ozpd.c
@@ -504,8 +504,6 @@ static void oz_retire_frame(struct oz_pd *pd, struct oz_tx_frame *f)
spin_unlock_bh(&pd->elt_buff.lock);
}
oz_tx_frame_free(pd, f);
- if (pd->elt_buff.free_elts > pd->elt_buff.max_free_elts)
- oz_trim_elt_pool(&pd->elt_buff);
}
/*
diff --git a/drivers/staging/ozwpan/ozpd.h b/drivers/staging/ozwpan/ozpd.h
index 3b3b3ce..43a26ea 100644
--- a/drivers/staging/ozwpan/ozpd.h
+++ b/drivers/staging/ozwpan/ozpd.h
@@ -130,4 +130,6 @@ void oz_handle_app_elt(struct oz_pd *pd, u8 app_id, struct oz_elt *elt);
void oz_apps_init(void);
void oz_apps_term(void);
+extern struct kmem_cache *oz_elt_info_cache;
+
#endif /* Sentry */
diff --git a/drivers/staging/ozwpan/ozproto.c b/drivers/staging/ozwpan/ozproto.c
index 549fe7f..b592e96 100644
--- a/drivers/staging/ozwpan/ozproto.c
+++ b/drivers/staging/ozwpan/ozproto.c
@@ -11,6 +11,7 @@
#include <linux/etherdevice.h>
#include <linux/errno.h>
#include <linux/ieee80211.h>
+#include <linux/slab.h>
#include "ozdbg.h"
#include "ozprotocol.h"
#include "ozeltbuf.h"
@@ -51,6 +52,8 @@ static u8 g_session_id;
static u16 g_apps = 0x1;
static int g_processing_rx;
+struct kmem_cache *oz_elt_info_cache;
+
/*
* Context: softirq-serialized
*/
@@ -479,6 +482,8 @@ void oz_protocol_term(void)
}
spin_unlock_bh(&g_polling_lock);
oz_dbg(ON, "Protocol stopped\n");
+
+ kmem_cache_destroy(oz_elt_info_cache);
}
/*
@@ -762,6 +767,10 @@ static char *oz_get_next_device_name(char *s, char *dname, int max_size)
*/
int oz_protocol_init(char *devs)
{
+ oz_elt_info_cache = KMEM_CACHE(oz_elt_info, 0);
+ if (!oz_elt_info_cache)
+ return -ENOMEM;
+
skb_queue_head_init(&g_rx_queue);
if (devs[0] == '*') {
oz_binding_add(NULL);
diff --git a/drivers/staging/ozwpan/ozproto.h b/drivers/staging/ozwpan/ozproto.h
index f1d30c4..b0f7459 100644
--- a/drivers/staging/ozwpan/ozproto.h
+++ b/drivers/staging/ozwpan/ozproto.h
@@ -65,4 +65,6 @@ enum hrtimer_restart oz_pd_timeout_event(struct hrtimer *timer);
int oz_get_pd_status_list(char *pd_list, int max_count);
int oz_get_binding_list(char *buf, int max_if);
+extern struct kmem_cache *oz_elt_info_cache;
+
#endif /* _OZPROTO_H */
--
1.9.1
--
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