[PATCH 09/14] drbd: Preallocate one page per drbd_socket as a send buffer

From: Philipp Reisner
Date: Wed Sep 07 2011 - 12:50:17 EST


From: Andreas Gruenbacher <agruen@xxxxxxxxxx>

Signed-off-by: Philipp Reisner <philipp.reisner@xxxxxxxxxx>
Signed-off-by: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>
---
drivers/block/drbd/drbd_int.h | 23 +----------------------
drivers/block/drbd/drbd_main.c | 6 +++++-
drivers/block/drbd/drbd_receiver.c | 4 ++--
drivers/block/drbd/drbd_worker.c | 2 +-
4 files changed, 9 insertions(+), 26 deletions(-)

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 4a4ecec..984b2a3 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -556,27 +556,6 @@ struct p_delay_probe93 {

#define DRBD_SOCKET_BUFFER_SIZE 4096

-union p_polymorph {
- struct p_header header;
- struct p_handshake handshake;
- struct p_data data;
- struct p_block_ack block_ack;
- struct p_barrier barrier;
- struct p_barrier_ack barrier_ack;
- struct p_rs_param_89 rs_param_89;
- struct p_rs_param_95 rs_param_95;
- struct p_protocol protocol;
- struct p_sizes sizes;
- struct p_uuids uuids;
- struct p_state state;
- struct p_req_state req_state;
- struct p_req_state_reply req_state_reply;
- struct p_block_req block_req;
- struct p_delay_probe93 delay_probe93;
- struct p_rs_uuid rs_uuid;
- struct p_block_desc block_desc;
-} __packed;
-
/**********************************************************************/
enum drbd_thread_state {
NONE,
@@ -804,7 +783,7 @@ struct drbd_socket {
struct socket *socket;
/* this way we get our
* send/receive buffers off the stack */
- union p_polymorph sbuf;
+ void *sbuf;
void *rbuf;
};

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 7b6da0e..6c2a51f 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -800,7 +800,7 @@ int drbd_send_sync_param(struct drbd_conf *mdev)
enum drbd_packet cmd =
apv >= 89 ? P_SYNC_PARAM89 : P_SYNC_PARAM;

- p = &mdev->tconn->data.sbuf.rs_param_95;
+ p = mdev->tconn->data.sbuf;

/* initialize verify_alg and csums_alg */
memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);
@@ -2279,11 +2279,15 @@ static int drbd_alloc_socket(struct drbd_socket *socket)
socket->rbuf = (void *) __get_free_page(GFP_KERNEL);
if (!socket->rbuf)
return -ENOMEM;
+ socket->sbuf = (void *) __get_free_page(GFP_KERNEL);
+ if (!socket->sbuf)
+ return -ENOMEM;
return 0;
}

static void drbd_free_socket(struct drbd_socket *socket)
{
+ free_page((unsigned long) socket->sbuf);
free_page((unsigned long) socket->rbuf);
}

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index e5099db..57e65ac 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -736,7 +736,7 @@ out:

static int drbd_send_fp(struct drbd_tconn *tconn, struct socket *sock, enum drbd_packet cmd)
{
- struct p_header *h = &tconn->data.sbuf.header;
+ struct p_header *h = tconn->data.sbuf;

return !_conn_send_cmd(tconn, 0, sock, cmd, h, sizeof(*h), 0);
}
@@ -4136,7 +4136,7 @@ static int drbd_disconnected(int vnr, void *p, void *data)
static int drbd_send_handshake(struct drbd_tconn *tconn)
{
/* ASSERT current == mdev->tconn->receiver ... */
- struct p_handshake *p = &tconn->data.sbuf.handshake;
+ struct p_handshake *p = tconn->data.sbuf;
int err;

if (mutex_lock_interruptible(&tconn->data.mutex)) {
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index e96a816..ed12cdf 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1195,7 +1195,7 @@ int w_send_barrier(struct drbd_work *w, int cancel)
{
struct drbd_tl_epoch *b = container_of(w, struct drbd_tl_epoch, w);
struct drbd_conf *mdev = w->mdev;
- struct p_barrier *p = &mdev->tconn->data.sbuf.barrier;
+ struct p_barrier *p = mdev->tconn->data.sbuf;
int err = 0;

/* really avoid racing with tl_clear. w.cb may have been referenced
--
1.7.4.1

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