Commit 2557d0c5 authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Dominique Martinet
Browse files

9p: Embed wait_queue_head into p9_req_t 

On a 64-bit system, the wait_queue_head_t is 24 bytes while the pointer
to it is 8 bytes.  Growing the p9_req_t by 16 bytes is better than
performing a 24-byte memory allocation.

Link: http://lkml.kernel.org/r/20180711210225.19730-5-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox <willy@infradead.org>
Reviewed-by: default avatarGreg Kurz <groug@kaod.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: default avatarDominique Martinet <dominique.martinet@cea.fr>
parent f28cdf04

include/net/9p/client.h

+1 −1
Original line number Diff line number Diff line
@@ -113,7 +113,7 @@ enum p9_req_status_t { 
struct p9_req_t {

	int status;

	int t_err;

	wait_queue_head_t *wq;

	wait_queue_head_t wq;

	struct p9_fcall *tc;

	struct p9_fcall *rc;

	void *aux;

net/9p/client.c

+5 −14
Original line number Diff line number Diff line
@@ -283,8 +283,9 @@ p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size) 
				return ERR_PTR(-ENOMEM);

			}

			for (col = 0; col < P9_ROW_MAXTAG; col++) {

				c->reqs[row][col].status = REQ_STATUS_IDLE;

				c->reqs[row][col].tc = NULL;

				req = &c->reqs[row][col];

				req->status = REQ_STATUS_IDLE;

				init_waitqueue_head(&req->wq);

			}

			c->max_tag += P9_ROW_MAXTAG;

		}
@@ -294,13 +295,6 @@ p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size) 
	col = tag % P9_ROW_MAXTAG;



	req = &c->reqs[row][col];

	if (!req->wq) {

		req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);

		if (!req->wq)

			goto grow_failed;

		init_waitqueue_head(req->wq);

	}



	if (!req->tc)

		req->tc = p9_fcall_alloc(alloc_msize);

	if (!req->rc)
@@ -320,9 +314,7 @@ grow_failed: 
	pr_err("Couldn't grow tag array\n");

	kfree(req->tc);

	kfree(req->rc);

	kfree(req->wq);

	req->tc = req->rc = NULL;

	req->wq = NULL;

	return ERR_PTR(-ENOMEM);

}
@@ -410,7 +402,6 @@ static void p9_tag_cleanup(struct p9_client *c) 
	/* free requests associated with tags */

	for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {

		for (col = 0; col < P9_ROW_MAXTAG; col++) {

			kfree(c->reqs[row][col].wq);

			kfree(c->reqs[row][col].tc);

			kfree(c->reqs[row][col].rc);

		}
@@ -453,7 +444,7 @@ void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status) 
	smp_wmb();

	req->status = status;



	wake_up(req->wq);

	wake_up(&req->wq);

	p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);

}

EXPORT_SYMBOL(p9_client_cb);
@@ -774,7 +765,7 @@ p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...) 
	}

again:

	/* Wait for the response */

	err = wait_event_killable(*req->wq, req->status >= REQ_STATUS_RCVD);

	err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);



	/*

	 * Make sure our req is coherent with regard to updates in other

net/9p/trans_virtio.c

+1 −1
Original line number Diff line number Diff line
@@ -490,7 +490,7 @@ req_retry_pinned: 
	virtqueue_kick(chan->vq);

	spin_unlock_irqrestore(&chan->lock, flags);

	p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");

	err = wait_event_killable(*req->wq, req->status >= REQ_STATUS_RCVD);

	err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);

	/*

	 * Non kernel buffers are pinned, unpin them

	 */

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