Re: [PATCH 2.6.35-rc6] net-next: Add multiqueue support to vmxnet3driver

From: Stephen Hemminger
Date: Wed Oct 13 2010 - 17:57:42 EST


On Wed, 13 Oct 2010 14:47:05 -0700 (PDT)
Shreyas Bhatewara <sbhatewara@xxxxxxxxxx> wrote:

> #ifdef VMXNET3_RSS
> +static unsigned int num_rss_entries;
> +#define VMXNET3_MAX_DEVICES 10
> +
> +static int rss_ind_table[VMXNET3_MAX_DEVICES *
> + VMXNET3_RSS_IND_TABLE_SIZE + 1] = {
> + [0 ... VMXNET3_MAX_DEVICES * VMXNET3_RSS_IND_TABLE_SIZE] = -1 };
> +#endif
> +static int num_tqs[VMXNET3_MAX_DEVICES + 1] = {
> + [0 ... VMXNET3_MAX_DEVICES] = 1 };
> +static int num_rqs[VMXNET3_MAX_DEVICES + 1] = {
> + [0 ... VMXNET3_MAX_DEVICES] = 1 };
> +static int share_tx_intr[VMXNET3_MAX_DEVICES + 1] = {
> + [0 ... VMXNET3_MAX_DEVICES] = 0 };
> +static int buddy_intr[VMXNET3_MAX_DEVICES + 1] = {
> + [0 ... VMXNET3_MAX_DEVICES] = 1 };
> +
> +static unsigned int num_adapters;
> +module_param_array(share_tx_intr, int, &num_adapters, 0400);
> +MODULE_PARM_DESC(share_tx_intr, "Share one IRQ among all tx queue completions. "
> + "Comma separated list of 1s and 0s - one for each NIC. "
> + "1 to share, 0 to not, default is 0");
> +module_param_array(buddy_intr, int, &num_adapters, 0400);
> +MODULE_PARM_DESC(buddy_intr, "Share one IRQ among corresponding tx and rx "
> + "queues. Comma separated list of 1s and 0s - one for each "
> + "NIC. 1 to share, 0 to not, default is 1");
> +module_param_array(num_tqs, int, &num_adapters, 0400);
> +MODULE_PARM_DESC(num_tqs, "Number of transmit queues in each adapter. Comma "
> + "separated list of integers. Setting this to 0 makes number"
> + " of queues same as number of CPUs. Default is 1.");
> +
> +#ifdef VMXNET3_RSS
> +module_param_array(rss_ind_table, int, &num_rss_entries, 0400);
> +MODULE_PARM_DESC(rss_ind_table, "RSS Indirection table. Number of entries "
> + "per NIC should be 32. Each integer in a comma separated list"
> + " is an rx queue number starting with 0. Repeat the same for"
> + " all NICs.");
> +module_param_array(num_rqs, int, &num_adapters, 0400);
> +MODULE_PARM_DESC(num_rqs, "Number of receive queues in each adapter. Comma "
> + " separated list of integers. Setting this to 0 makes number"
> + " of queues same as number of CPUs. Default is 1.");

Module parameters are not right for this. They lead to different API
for interacting with each driver vendor. Is there a another better API?
Does it have to be this tweakable in a production environment.

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