diff options
| author | Dave Jiang <dave.jiang@intel.com> | 2015-05-19 16:45:46 -0400 |
|---|---|---|
| committer | Jon Mason <jdmason@kudzu.us> | 2015-07-04 14:09:21 -0400 |
| commit | 06917f753547e6bba8a5d17f79971d1c071a70dd (patch) | |
| tree | c7dd7a7c0e94bd380a1c89d7d14e5c600c15ad78 /drivers | |
| parent | 0e041fb5369975c183d22ffeb156ea0dae760088 (diff) | |
| download | lwn-06917f753547e6bba8a5d17f79971d1c071a70dd.tar.gz lwn-06917f753547e6bba8a5d17f79971d1c071a70dd.zip | |
NTB: Improve performance with write combining
Changing the memory window BAR mappings to write combining significantly
boosts the performance. We will also use memcpy that uses non-temporal
store, which showed performance improvement when doing non-cached
memcpys.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/ntb/ntb_transport.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index dc14ec81c43e..7a765d3230d8 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -58,6 +58,7 @@ #include <linux/pci.h> #include <linux/slab.h> #include <linux/types.h> +#include <linux/uaccess.h> #include "linux/ntb.h" #include "linux/ntb_transport.h" @@ -993,7 +994,7 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev) if (rc) goto err1; - mw->vbase = ioremap(mw->phys_addr, mw->phys_size); + mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size); if (!mw->vbase) { rc = -ENOMEM; goto err1; @@ -1375,7 +1376,15 @@ static void ntb_tx_copy_callback(void *data) static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset) { +#ifdef ARCH_HAS_NOCACHE_UACCESS + /* + * Using non-temporal mov to improve performance on non-cached + * writes, even though we aren't actually copying from user space. + */ + __copy_from_user_inatomic_nocache(offset, entry->buf, entry->len); +#else memcpy_toio(offset, entry->buf, entry->len); +#endif /* Ensure that the data is fully copied out before setting the flags */ wmb(); |