Commit f1d20d86 authored by Jan Beulich's avatar Jan Beulich Committed by Boris Ostrovsky
Browse files

Xen/gntdev: don't needlessly use kvcalloc() 



Requesting zeroed memory when all of it will be overwritten subsequently
by all ones is a waste of processing bandwidth. In fact, rather than
recording zeroed ->grants[], fill that array too with more appropriate
"invalid" indicators.

Signed-off-by: default avatarJan Beulich <jbeulich@suse.com>
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/9a726be2-4893-8ffe-0ef1-b70dd1c229b1@suse.com


Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
parent bce21a2b

drivers/xen/gntdev.c

+12 −7
Original line number Diff line number Diff line
@@ -133,9 +133,12 @@ struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count, 
	if (NULL == add)

		return NULL;



	add->grants    = kvcalloc(count, sizeof(add->grants[0]), GFP_KERNEL);

	add->map_ops   = kvcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL);

	add->unmap_ops = kvcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL);

	add->grants    = kvmalloc_array(count, sizeof(add->grants[0]),

					GFP_KERNEL);

	add->map_ops   = kvmalloc_array(count, sizeof(add->map_ops[0]),

					GFP_KERNEL);

	add->unmap_ops = kvmalloc_array(count, sizeof(add->unmap_ops[0]),

					GFP_KERNEL);

	add->pages     = kvcalloc(count, sizeof(add->pages[0]), GFP_KERNEL);

	if (NULL == add->grants    ||

	    NULL == add->map_ops   ||
@@ -143,9 +146,9 @@ struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count, 
	    NULL == add->pages)

		goto err;

	if (use_ptemod) {

		add->kmap_ops   = kvcalloc(count, sizeof(add->kmap_ops[0]),

		add->kmap_ops   = kvmalloc_array(count, sizeof(add->kmap_ops[0]),

						 GFP_KERNEL);

		add->kunmap_ops = kvcalloc(count, sizeof(add->kunmap_ops[0]),

		add->kunmap_ops = kvmalloc_array(count, sizeof(add->kunmap_ops[0]),

						 GFP_KERNEL);

		if (NULL == add->kmap_ops || NULL == add->kunmap_ops)

			goto err;
@@ -186,6 +189,8 @@ struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count, 
		goto err;



	for (i = 0; i < count; i++) {

		add->grants[i].domid = DOMID_INVALID;

		add->grants[i].ref = INVALID_GRANT_REF;

		add->map_ops[i].handle = INVALID_GRANT_HANDLE;

		add->unmap_ops[i].handle = INVALID_GRANT_HANDLE;

		if (use_ptemod) {