I/OAT: tcp_dma_copybreak default value dependent on I/OAT version
I/OAT DMA performance tuning showed different optimal values of
tcp_dma_copybreak for different I/OAT versions (4096 for 1.2 and 2048
for 2.0). This patch lets ioatdma driver set tcp_dma_copybreak value
according to these results.
[dan.j.williams@intel.com: remove some ifdefs]
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/dma/ioatdma.h b/drivers/dma/ioatdma.h
index c6ec933..685adb6 100644
--- a/drivers/dma/ioatdma.h
+++ b/drivers/dma/ioatdma.h
@@ -27,6 +27,7 @@
#include <linux/dmapool.h>
#include <linux/cache.h>
#include <linux/pci_ids.h>
+#include <net/tcp.h>
#define IOAT_DMA_VERSION "2.18"
@@ -129,6 +130,20 @@
struct dma_async_tx_descriptor async_tx;
};
+static inline void ioat_set_tcp_copy_break(struct ioatdma_device *dev)
+{
+ #ifdef CONFIG_NET_DMA
+ switch (dev->version) {
+ case IOAT_VER_1_2:
+ sysctl_tcp_dma_copybreak = 4096;
+ break;
+ case IOAT_VER_2_0:
+ sysctl_tcp_dma_copybreak = 2048;
+ break;
+ }
+ #endif
+}
+
#if defined(CONFIG_INTEL_IOATDMA) || defined(CONFIG_INTEL_IOATDMA_MODULE)
struct ioatdma_device *ioat_dma_probe(struct pci_dev *pdev,
void __iomem *iobase);