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From: Auke Kok <>
To: Auke Kok <>
Cc: linux-pci maillist <>,
	Linux Kernel Mailing List <>,, Andrew Morton <>,
	Linus Torvalds <>,
	Jesse Brandeburg <>
Subject: Re: Possible regression: MSI vector leakage since 2.6.18-rc5ish (Unable to repeatedly allocate/free MSI interrupt)
Date: Fri, 26 Jan 2007 14:50:52 -0800	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

Auke Kok wrote:
> Hi,
> I've established a regression in the MSI vector/irq allocation routine for both 
> i386 and x86_64. Our test labs repeatedly modprobe/rmmod the e1000 driver for 
> serveral minutes which allocates msi vectors and frees them. These tests have 
> been running fine until 2.6.19.
> git-bisecting I've established that in between commit 
> 04b9267b15206fc902a18de1f78de6c82ca47716 "Eric W. Biederman -- genirq: x86_64 
> irq: Remove the msi assumption that irq == vector" and commit 
> f29bd1ba68c8c6a0f50bd678bbd5a26674018f7c "Ingo Molnar -- genirq: convert the 
> x86_64 architecture to irq-chips" the behaviour broke.
> The revisions in between seem to be dependent and give all sorts of other 
> issues, so it's rather hard for me to bisect that and give trustworthy results.
> the e1000 driver hits the 256-mark cycle (I think - it consistently refuses to 
> do 500 msi irq/vector allocations which is my test case) and throws:
> e1000: eth4: e1000_request_irq: Unable to allocate MSI interrupt Error: -16
> which is caused by a `if ((err = pci_enable_msi(adapter->pdev))) {` call from 
> the e1000 driver. It's rather easy to hit this mark with the new 4-port e1000 
> adapters :).
> as for the e1000 code, I can say that even our oldest msi-enabled e1000 driver 
> works fine with 2.6.18 and under. All kernels from 2.6.19 fail consistently.
> I mostly suspect commit 7bd007e480672c99d8656c7b7b12ef0549432c37 at the moment. 
> Perhaps Eric Biederman can help?


The exact same problem exists when doing "for n in `seq 1 300` ; do modprobe 
snd_hda_intel enable_msi ; rmmod snd_hda_intel ; done".

I'm sure it will show up for other msi enabled devices.

  reply	other threads:[~2007-01-26 22:50 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-26 22:38 Auke Kok
2007-01-26 22:50 ` Auke Kok [this message]
2007-01-27  9:28 ` Eric W. Biederman
2007-01-27 19:07   ` Auke Kok
2007-01-27 19:28     ` Eric W. Biederman
2007-01-27 19:39       ` Auke Kok
2007-01-29 19:00   ` Auke Kok
2007-01-29 19:36     ` Linus Torvalds
2007-01-29 19:42       ` Eric W. Biederman
2007-01-29 20:19       ` [PATCH] i386: In assign_irq_vector look at all vectors before giving up Eric W. Biederman

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