Messages in this thread Patch in this message | | | From | Maciej Sosnowski <> | Subject | [PATCH 5/7] I/OAT: set tcp_dma_copybreak to 256k for I/OAT ver.3 | Date | Thu, 26 Feb 2009 11:05:17 +0100 |
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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.krisher@intel.com> ---
drivers/dma/ioatdma.h | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/drivers/dma/ioatdma.h b/drivers/dma/ioatdma.h index a3306d0..dcf8db5 100644 --- a/drivers/dma/ioatdma.h +++ b/drivers/dma/ioatdma.h @@ -135,12 +135,14 @@ static inline void ioat_set_tcp_copy_bre #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 }
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