Allocate the cache_request object and it's buffer in a single
contiguous memory allocation instead of two separate ones.
Code trawling shows that none of the users of caches make upcalls
anywhere near even the small x86 PAGE_SIZE, so we can afford to lose
a few bytes. One less allocation makes the code a little simpler.
Signed-off-by: Greg Banks <[email protected]>
---
net/sunrpc/cache.c | 28 ++++++++--------------------
1 file changed, 8 insertions(+), 20 deletions(-)
Index: bfields/net/sunrpc/cache.c
===================================================================
--- bfields.orig/net/sunrpc/cache.c
+++ bfields/net/sunrpc/cache.c
@@ -689,8 +689,8 @@ void cache_clean_deferred(void *owner)
struct cache_request {
struct list_head list;
struct cache_head *item;
- char * buf;
int len;
+ char buf[0];
};
static ssize_t
@@ -741,7 +741,6 @@ cache_read(struct file *filp, char __use
error:
/* need to release rq */
cache_put(rq->item, cd);
- kfree(rq->buf);
kfree(rq);
return err;
@@ -893,7 +892,6 @@ static void cache_remove_queued(struct c
/* if found, destroy */
if (rq) {
cache_put(rq->item, cd);
- kfree(rq->buf);
kfree(rq);
}
}
@@ -983,15 +981,13 @@ static void warn_no_listener(struct cach
/*
* register an upcall request to user-space.
- * Each request is at most one page long.
+ * Each request is at most (slightly less than) one page long.
*/
static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h)
{
-
- char *buf;
struct cache_request *rq;
char *bp;
- int len;
+ int len; /* bytes remaining in the buffer */
if (cd->cache_request == NULL)
return -EINVAL;
@@ -1002,28 +998,20 @@ static int cache_make_upcall(struct cach
return -EINVAL;
}
- buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
- if (!buf)
- return -EAGAIN;
-
- rq = kmalloc(sizeof (*rq), GFP_KERNEL);
- if (!rq) {
- kfree(buf);
+ rq = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!rq)
return -EAGAIN;
- }
-
- bp = buf; len = PAGE_SIZE;
+ bp = rq->buf;
+ len = PAGE_SIZE - sizeof(*rq);
cd->cache_request(cd, h, &bp, &len);
if (len < 0) {
- kfree(buf);
kfree(rq);
return -EAGAIN;
}
rq->item = cache_get(h);
- rq->buf = buf;
- rq->len = PAGE_SIZE - len;
+ rq->len = PAGE_SIZE - sizeof(*rq) - len;
spin_lock(&cd->queue_lock);
list_add_tail(&rq->list, &cd->to_read);
spin_unlock(&cd->queue_lock);
--
--
Greg Banks, P.Engineer, SGI Australian Software Group.
the brightly coloured sporks of revolution.
I don't speak for SGI.