| Message ID | 1724735791-22815-1-git-send-email-ernis@linux.microsoft.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 646f071d315b75e87583de290d333478d42ccde1 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v4] net: netvsc: Update default VMBus channels | expand |
From: Erni Sri Satya Vennela <ernis@linux.microsoft.com> Sent: Monday, August 26, 2024 10:17 PM > > Change VMBus channels macro (VRSS_CHANNEL_DEFAULT) in > Linux netvsc from 8 to 16 to align with Azure Windows VM > and improve networking throughput. > > For VMs having less than 16 vCPUS, the channels depend > on number of vCPUs. For greater than 16 vCPUs, > set the channels to maximum of VRSS_CHANNEL_DEFAULT and > number of physical cores / 2 which is returned by > netif_get_num_default_rss_queues() as a way to optimize CPU > resource utilization and scale for high-end processors with > many cores. > Maximum number of channels are by default set to 64. > > Based on this change the channel creation would change as follows: > > ----------------------------------------------------------------- > | No. of vCPU | dev_info->num_chn | channels created | > ----------------------------------------------------------------- > | 1-16 | 16 | vCPU | > | >16 | max(16,#cores/2) | min(64 , max(16,#cores/2)) | > ----------------------------------------------------------------- > > Performance tests showed significant improvement in throughput: > - 0.54% for 16 vCPUs > - 0.83% for 32 vCPUs > - 0.86% for 48 vCPUs > - 9.72% for 64 vCPUs > - 13.57% for 96 vCPUs > > Signed-off-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com> > Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> > Reviewed-by: Shradha Gupta <shradhagupta@linux.microsoft.com> > --- > Changes in v4: > * Update commit message for channels created > --- > Changes in v3: > * Use netif_get_num_default_rss_queues() to set channels > * Change terminology for channels in commit message > --- > Changes in v2: > * Set dev_info->num_chn based on vCPU count. > --- > drivers/net/hyperv/hyperv_net.h | 2 +- > drivers/net/hyperv/netvsc_drv.c | 3 ++- > 2 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h > index 810977952f95..e690b95b1bbb 100644 > --- a/drivers/net/hyperv/hyperv_net.h > +++ b/drivers/net/hyperv/hyperv_net.h > @@ -882,7 +882,7 @@ struct nvsp_message { > > #define VRSS_SEND_TAB_SIZE 16 /* must be power of 2 */ > #define VRSS_CHANNEL_MAX 64 > -#define VRSS_CHANNEL_DEFAULT 8 > +#define VRSS_CHANNEL_DEFAULT 16 > > #define RNDIS_MAX_PKT_DEFAULT 8 > #define RNDIS_PKT_ALIGN_DEFAULT 8 > diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c > index 44142245343d..a6482afe4217 100644 > --- a/drivers/net/hyperv/netvsc_drv.c > +++ b/drivers/net/hyperv/netvsc_drv.c > @@ -987,7 +987,8 @@ struct netvsc_device_info *netvsc_devinfo_get(struct > netvsc_device *nvdev) > dev_info->bprog = prog; > } > } else { > - dev_info->num_chn = VRSS_CHANNEL_DEFAULT; > + dev_info->num_chn = max(VRSS_CHANNEL_DEFAULT, > + netif_get_num_default_rss_queues()); > dev_info->send_sections = NETVSC_DEFAULT_TX; > dev_info->send_section_size = NETVSC_SEND_SECTION_SIZE; > dev_info->recv_sections = NETVSC_DEFAULT_RX; > -- > 2.34.1 > Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Mon, 26 Aug 2024 22:16:31 -0700 you wrote: > Change VMBus channels macro (VRSS_CHANNEL_DEFAULT) in > Linux netvsc from 8 to 16 to align with Azure Windows VM > and improve networking throughput. > > For VMs having less than 16 vCPUS, the channels depend > on number of vCPUs. For greater than 16 vCPUs, > set the channels to maximum of VRSS_CHANNEL_DEFAULT and > number of physical cores / 2 which is returned by > netif_get_num_default_rss_queues() as a way to optimize CPU > resource utilization and scale for high-end processors with > many cores. > Maximum number of channels are by default set to 64. > > [...] Here is the summary with links: - [v4] net: netvsc: Update default VMBus channels https://git.kernel.org/netdev/net-next/c/646f071d315b You are awesome, thank you!
diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h index 810977952f95..e690b95b1bbb 100644 --- a/drivers/net/hyperv/hyperv_net.h +++ b/drivers/net/hyperv/hyperv_net.h @@ -882,7 +882,7 @@ struct nvsp_message { #define VRSS_SEND_TAB_SIZE 16 /* must be power of 2 */ #define VRSS_CHANNEL_MAX 64 -#define VRSS_CHANNEL_DEFAULT 8 +#define VRSS_CHANNEL_DEFAULT 16 #define RNDIS_MAX_PKT_DEFAULT 8 #define RNDIS_PKT_ALIGN_DEFAULT 8 diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 44142245343d..a6482afe4217 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -987,7 +987,8 @@ struct netvsc_device_info *netvsc_devinfo_get(struct netvsc_device *nvdev) dev_info->bprog = prog; } } else { - dev_info->num_chn = VRSS_CHANNEL_DEFAULT; + dev_info->num_chn = max(VRSS_CHANNEL_DEFAULT, + netif_get_num_default_rss_queues()); dev_info->send_sections = NETVSC_DEFAULT_TX; dev_info->send_section_size = NETVSC_SEND_SECTION_SIZE; dev_info->recv_sections = NETVSC_DEFAULT_RX;