cifs: keep a reusable kvec array for receives
Having to continually allocate a new kvec array is expensive. Allocate
one that's big enough, and only reallocate it as needed.
Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 4860940..ee70075 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -410,6 +410,24 @@
return nr_segs;
}
+static struct kvec *
+get_server_iovec(struct TCP_Server_Info *server, unsigned int nr_segs)
+{
+ struct kvec *new_iov;
+
+ if (server->iov && nr_segs <= server->nr_iov)
+ return server->iov;
+
+ /* not big enough -- allocate a new one and release the old */
+ new_iov = kmalloc(sizeof(*new_iov) * nr_segs, GFP_NOFS);
+ if (new_iov) {
+ kfree(server->iov);
+ server->iov = new_iov;
+ server->nr_iov = nr_segs;
+ }
+ return new_iov;
+}
+
static int
readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
unsigned int nr_segs, unsigned int to_read)
@@ -420,7 +438,7 @@
struct msghdr smb_msg;
struct kvec *iov;
- iov = kmalloc(sizeof(*iov_orig) * nr_segs, GFP_NOFS);
+ iov = get_server_iovec(server, nr_segs);
if (!iov)
return -ENOMEM;
@@ -464,7 +482,6 @@
break;
}
}
- kfree(iov);
return total_read;
}
@@ -669,6 +686,7 @@
}
kfree(server->hostname);
+ kfree(server->iov);
kfree(server);
length = atomic_dec_return(&tcpSesAllocCount);