ioat2,3: cacheline align software descriptor allocations

All the necessary fields for handling an ioat2,3 ring entry can fit into
one cacheline.  Move ->len prior to ->txd in struct ioat_ring_ent, and
move allocation of these entries to a hw-cache-aligned kmem cache to
reduce the number of cachelines dirtied for descriptor management.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams
2009-09-08 17:53:04 -07:00
parent 0803172778
commit 162b96e63e
3 changed files with 20 additions and 4 deletions

View File

@@ -69,6 +69,8 @@ static int ioat_dca_enabled = 1;
module_param(ioat_dca_enabled, int, 0644);
MODULE_PARM_DESC(ioat_dca_enabled, "control support of dca service (default: 1)");
struct kmem_cache *ioat2_cache;
#define DRV_NAME "ioatdma"
static struct pci_driver ioat_pci_driver = {
@@ -168,12 +170,24 @@ static void __devexit ioat_remove(struct pci_dev *pdev)
static int __init ioat_init_module(void)
{
return pci_register_driver(&ioat_pci_driver);
int err;
ioat2_cache = kmem_cache_create("ioat2", sizeof(struct ioat_ring_ent),
0, SLAB_HWCACHE_ALIGN, NULL);
if (!ioat2_cache)
return -ENOMEM;
err = pci_register_driver(&ioat_pci_driver);
if (err)
kmem_cache_destroy(ioat2_cache);
return err;
}
module_init(ioat_init_module);
static void __exit ioat_exit_module(void)
{
pci_unregister_driver(&ioat_pci_driver);
kmem_cache_destroy(ioat2_cache);
}
module_exit(ioat_exit_module);