From 5de22343b2303b278ab562e5d166ffe306566d30 Mon Sep 17 00:00:00 2001 From: Maciej Sosnowski Date: Thu, 26 Feb 2009 11:05:17 +0100 Subject: [PATCH] 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 Signed-off-by: Shannon Nelson Acked-by: Jeff Kirsher Signed-off-by: Dan Williams --- drivers/dma/ioatdma.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) 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 } -- 2.39.5