From: Mark Lord <kernel@start.ca>
To: Alexander Gordeev <agordeev@redhat.com>
Cc: linuxppc-dev@lists.ozlabs.org, Joerg Roedel <joro@8bytes.org>,
"x86@kernel.org" <x86@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-ide@vger.kernel.org" <linux-ide@vger.kernel.org>,
Jan Beulich <JBeulich@suse.com>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
Tejun Heo <tj@kernel.org>, Bjorn Helgaas <bhelgaas@google.com>,
Ingo Molnar <mingo@kernel.org>
Subject: Re: [PATCH v2 2/6] PCI/MSI: Factor out pci_get_msi_cap() interface
Date: Tue, 01 Oct 2013 22:46:32 -0400 [thread overview]
Message-ID: <524B8908.8080607@start.ca> (raw)
In-Reply-To: <20130926130328.GD16774@dhcp-26-207.brq.redhat.com>
On 13-09-26 09:03 AM, Alexander Gordeev wrote:
> On Thu, Sep 26, 2013 at 08:32:53AM -0400, Mark Lord wrote:
>> On 13-09-18 05:48 AM, Alexander Gordeev wrote:
>>> The last pattern makes most of sense to me and could be updated with a more
>>> clear sequence - a call to (bit modified) pci_msix_table_size() followed
>>> by a call to pci_enable_msix(). I think this pattern can effectively
>>> supersede the currently recommended "loop" practice.
>>
>> The loop is still necessary, because there's a race between those two calls,
>> so that pci_enable_msix() can still fail due to lack of MSIX slots.
>
> Moreover, the existing loop pattern is racy and could fail just as easily ;)
Yes, but it then loops again to correct things.
> But (1) that is something drivers should expect and (2) there is basically
> nothing to race against - that is probably the reason it has not been a
> problem for pSeries. So I think we should not care about this.
I always care about race conditions.
next prev parent reply other threads:[~2013-10-02 2:46 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20130905150259.GA30984@dhcp-26-207.brq.redhat.com>
[not found] ` <20130905150442.GA24148@htj.dyndns.org>
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[not found] ` <CAErSpo4TU2geqzY3AYsL08KimBqtfwa4iUoFHgcFt0zMTBJkHw@mail.gmail.com>
[not found] ` <20130906160621.GF22763@mtj.dyndns.org>
[not found] ` <20130906233205.GF12956@google.com>
[not found] ` <20130909152044.GA24962@dhcp-26-207.brq.redhat.com>
2013-09-16 10:22 ` [PATCH v2 2/6] PCI/MSI: Factor out pci_get_msi_cap() interface Alexander Gordeev
2013-09-17 14:30 ` Michael Ellerman
2013-09-18 9:48 ` Alexander Gordeev
2013-09-18 14:22 ` Tejun Heo
2013-09-18 16:50 ` Alexander Gordeev
2013-09-20 8:24 ` Alexander Gordeev
2013-09-20 12:27 ` Tejun Heo
2013-09-25 18:02 ` Bjorn Helgaas
2013-09-25 20:58 ` Alexander Gordeev
2013-09-25 21:00 ` Tejun Heo
2013-09-26 7:46 ` Alexander Gordeev
2013-09-26 8:58 ` David Laight
2013-09-26 10:45 ` Alexander Gordeev
2013-09-26 11:34 ` David Laight
2013-09-26 12:13 ` Alexander Gordeev
2013-09-26 13:11 ` Tejun Heo
2013-09-26 14:39 ` Alexander Gordeev
2013-09-26 14:42 ` Tejun Heo
2013-10-01 7:19 ` Michael Ellerman
2013-09-20 12:26 ` Tejun Heo
2013-10-01 7:26 ` Michael Ellerman
2013-10-01 7:35 ` Michael Ellerman
2013-10-01 11:55 ` Tejun Heo
2013-10-02 2:33 ` Michael Ellerman
2013-10-02 3:23 ` Tejun Heo
2013-09-26 12:32 ` Mark Lord
2013-09-26 13:03 ` Alexander Gordeev
2013-10-02 2:46 ` Mark Lord [this message]
2013-10-02 7:26 ` Alexander Gordeev
2013-12-18 18:26 ` Bjorn Helgaas
2013-10-01 7:51 ` Michael Ellerman
2013-10-01 10:35 ` Alexander Gordeev
2013-10-02 2:43 ` Michael Ellerman
2013-10-02 7:10 ` Alexander Gordeev
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