From: Clemens Ladisch <clemens@ladisch.de>
To: Roland Dreier <roland@purestorage.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Micha Nelissen <micha@neli.hopto.org>,
Jesse Barnes <jbarnes@virtuousgeek.org>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, "Venkatesh Pallipadi (Venki)" <venki@google.com>,
linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
Matthew Wilcox <matthew@wil.cx>
Subject: Re: [PATCH] Add support for multiple MSI on x86
Date: Thu, 10 Mar 2011 16:33:48 +0100 [thread overview]
Message-ID: <4D78EF5C.5090504@ladisch.de> (raw)
In-Reply-To: <AANLkTinrzY56cwB6OX6xcAb5ZWJcZC5cr-knLkCDPy6p@mail.gmail.com>
Roland Dreier wrote:
> > Yes, but there are MSI devices in the field...
>
> But do any of them benefit from having multiple interrupt vectors available?
>
> If I recall correct, willy was motivated by AHCI performance to try this out,
> and in the end things didn't go any faster using multiple MSI.
>
> The big win with multiple interrupt vectors is when you have independent
> queues that you can point different CPUs at, and give each CPU its own
> interrupt.
And this is how AHCI is designed, but libahci.c currently wraps its
interrupt handler in a device-wide lock. I don't know if that test also
reorganized the driver code.
Regards,
Clemens
prev parent reply other threads:[~2011-03-10 15:32 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-13 20:25 [PATCH] Add support for multiple MSI on x86 Micha Nelissen
2011-02-14 12:34 ` Ingo Molnar
2011-02-14 19:47 ` Micha Nelissen
2011-02-15 2:38 ` Ingo Molnar
2011-02-14 20:55 ` Thomas Gleixner
2011-03-04 18:37 ` Jesse Barnes
2011-06-17 17:12 ` Matthew Wilcox
2011-03-04 18:36 ` Jesse Barnes
2011-03-04 19:53 ` Micha Nelissen
2011-03-08 21:05 ` Thomas Gleixner
[not found] ` <35bd5f56-658b-48e3-a376-b07350a29cf6@email.android.com>
2011-03-08 21:16 ` Thomas Gleixner
[not found] ` <71ed11a4-aff7-4eb6-b037-0e097bb96444@email.android.com>
2011-03-08 22:13 ` Thomas Gleixner
2011-03-10 2:05 ` Roland Dreier
2011-03-10 15:33 ` Clemens Ladisch [this message]
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