Re: [PATCH 2 08/24] hpsa: choose number of reply queues more intelligently.

[Christoph Hellwig <hch@infradead.org>]

On Thu, May 29, 2014 at 10:53:02AM -0500, Stephen M. Cameron wrote:
> From: Stephen M. Cameron <scameron@beardog.cce.hp.com>
> 
> No sense having 8 or 16 reply queues if you only have 4 cpus,
> and likewise no sense limiting to 8 reply queues if you have
> many more cpus.

I've applied this as it looks good as-is, but shouldn't we also
cap the number of MSI-X vectors in common code so that we avoid
adding this as boilerplate code to lots of drivers?

> 
> Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
> Reviewed-by: Mike Miller <michael.miller@canonical.com>
> Reviewed-by: Scott Teel <scott.teel@hp.com>
> ---
>  drivers/scsi/hpsa.c     |    2 ++
>  drivers/scsi/hpsa_cmd.h |    2 +-
>  2 files changed, 3 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
> index b1ecfd8..b903e86 100644
> --- a/drivers/scsi/hpsa.c
> +++ b/drivers/scsi/hpsa.c
> @@ -6157,6 +6157,8 @@ static void hpsa_interrupt_mode(struct ctlr_info *h)
>  	if (pci_find_capability(h->pdev, PCI_CAP_ID_MSIX)) {
>  		dev_info(&h->pdev->dev, "MSIX\n");
>  		h->msix_vector = MAX_REPLY_QUEUES;
> +		if (h->msix_vector > num_online_cpus())
> +			h->msix_vector = num_online_cpus();
>  		err = pci_enable_msix(h->pdev, hpsa_msix_entries,
>  				      h->msix_vector);
>  		if (err > 0) {
> diff --git a/drivers/scsi/hpsa_cmd.h b/drivers/scsi/hpsa_cmd.h
> index db89245..104b67b 100644
> --- a/drivers/scsi/hpsa_cmd.h
> +++ b/drivers/scsi/hpsa_cmd.h
> @@ -615,7 +615,7 @@ struct TransTable_struct {
>  	u32            RepQCount;
>  	u32            RepQCtrAddrLow32;
>  	u32            RepQCtrAddrHigh32;
> -#define MAX_REPLY_QUEUES 8
> +#define MAX_REPLY_QUEUES 64
>  	struct vals32  RepQAddr[MAX_REPLY_QUEUES];
>  };
>  
> 
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