From: Matthew Wilcox <matthew@wil.cx>
To: Sheng Yang <sheng@linux.intel.com>
Cc: kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>,
jbarnes@virtuousgeek.org, linux-kernel@vger.kernel.org,
linux-pci@vger.kernel.org, Matthew Wilcox <willy@linux.intel.com>,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH] msi-x: let drivers retry when not enough vectors
Date: Thu, 7 May 2009 03:27:31 -0600 [thread overview]
Message-ID: <20090507092731.GH8112@parisc-linux.org> (raw)
In-Reply-To: <200905071651.24970.sheng@linux.intel.com>
On Thu, May 07, 2009 at 04:51:24PM +0800, Sheng Yang wrote:
> On Thursday 07 May 2009 16:28:41 Michael S. Tsirkin wrote:
> > pci_enable_msix currently returns -EINVAL if you ask
> > for more vectors than supported by the device, which would
> > typically cause fallback to regular interrupts.
> >
> > It's better to return the table size, making the driver retry
> > MSI-X with less vectors.
>
> Hi Michael
>
> I think driver should read from capability list to know how many vector
> supported by this device before enable MSI-X for device, as
> pci_msix_table_size() did...
I think Michael's patch makes sense. It reduces the amount of work the
driver has to do without requiring any additional work in the core. I
don't see the disadvantage to it.
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
--
Matthew Wilcox Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."
next prev parent reply other threads:[~2009-05-07 9:33 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-07 8:28 [PATCH] msi-x: let drivers retry when not enough vectors Michael S. Tsirkin
2009-05-07 8:51 ` Sheng Yang
2009-05-07 9:05 ` Michael S. Tsirkin
2009-05-07 9:10 ` Sheng Yang
2009-05-07 9:31 ` Michael S. Tsirkin
2009-05-07 9:27 ` Matthew Wilcox [this message]
2009-05-07 9:40 ` Sheng Yang
2009-05-07 9:53 ` Matthew Wilcox
2009-05-07 10:19 ` Sheng Yang
2009-05-07 10:32 ` Michael S. Tsirkin
2009-05-07 23:55 ` Rusty Russell
2009-05-08 0:22 ` Matthew Wilcox
2009-05-08 0:28 ` Michael Ellerman
2009-05-12 21:28 ` Michael S. Tsirkin
2009-05-07 10:23 ` Michael Ellerman
2009-05-07 10:28 ` Sheng Yang
2009-05-07 10:44 ` Avi Kivity
2009-05-07 11:57 ` Matthew Wilcox
2009-06-11 18:28 ` Jesse Barnes
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