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authorMaciej Sosnowski <maciej.sosnowski@intel.com>2009-02-26 11:05:17 +0100
committerDan Williams <dan.j.williams@intel.com>2009-03-04 16:04:40 -0700
commit5de22343b2303b278ab562e5d166ffe306566d30 (patch)
tree6c48b83e1dc60afb6d22d3afc74058bbcfaa87d7
parent2b8a6bf896ef47cc7d84c503079cc7b99789f9fa (diff)
downloadlinux-5de22343b2303b278ab562e5d166ffe306566d30.tar.bz2
I/OAT: set tcp_dma_copybreak to 256k for I/OAT ver.3
Upcoming server platforms from Intel based on the Nehalem performance have significantly improved CPU based copy performance. However, the DMA engine can still be effective at higher I/O sizes for TCP traffic and at this time copybreak should be set to 256k for TCP traffic only. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Shannon Nelson <shannon.nelson@intel.com> Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
-rw-r--r--drivers/dma/ioatdma.h4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/dma/ioatdma.h b/drivers/dma/ioatdma.h
index a3306d0e1372..dcf8db513c3a 100644
--- a/drivers/dma/ioatdma.h
+++ b/drivers/dma/ioatdma.h
@@ -135,12 +135,14 @@ static inline void ioat_set_tcp_copy_break(struct ioatdma_device *dev)
#ifdef CONFIG_NET_DMA
switch (dev->version) {
case IOAT_VER_1_2:
- case IOAT_VER_3_0:
sysctl_tcp_dma_copybreak = 4096;
break;
case IOAT_VER_2_0:
sysctl_tcp_dma_copybreak = 2048;
break;
+ case IOAT_VER_3_0:
+ sysctl_tcp_dma_copybreak = 262144;
+ break;
}
#endif
}