Re: [Xen-devel] Xen-unstable Linux 3.14-rc3 and 3.13 Network troubles "bisected"

Sander Eikelenboom
2014-03-26T17:33:10Z

Hi Paul,

Seems your last mail arrived in pretty bad shape (truncated) in my mailbox ..

--
Sander

Wednesday, March 26, 2014, 6:16:49 PM, you wrote:

>> -----Original Message-----
>> From: Sander Eikelenboom [mailto:linux@eikelenboom.it]
>> Sent: 26 March 2014 16:54
>> To: Paul Durrant
>> Cc: Wei Liu; annie li; Zoltan Kiss; xen-devel@lists.xen.org; Ian Campbell; linux-
>> kernel; netdev@vger.kernel.org
>> Subject: Re: [Xen-devel] Xen-unstable Linux 3.14-rc3 and 3.13 Network
>> troubles "bisected"
>>
>>
>> Wednesday, March 26, 2014, 5:25:21 PM, you wrote:
>>
>> >> -----Original Message-----
>> >> From: Sander Eikelenboom [mailto:linux@eikelenboom.it]
>> >> Sent: 26 March 2014 16:07
>> >> To: Paul Durrant
>> >> Cc: Wei Liu; annie li; Zoltan Kiss; xen-devel@lists.xen.org; Ian Campbell;
>> linux-
>> >> kernel; netdev@vger.kernel.org
>> >> Subject: Re: [Xen-devel] Xen-unstable Linux 3.14-rc3 and 3.13 Network
>> >> troubles "bisected"
>> >>
>> >>
>> >> Wednesday, March 26, 2014, 4:50:30 PM, you wrote:
>> >>
>> >> >> -----Original Message-----
>> >> >> From: Sander Eikelenboom [mailto:linux@eikelenboom.it]
>> >> >> Sent: 26 March 2014 15:23
>> >> >> To: Paul Durrant
>> >> >> Cc: Wei Liu; annie li; Zoltan Kiss; xen-devel@lists.xen.org; Ian Campbell;
>> >> linux-
>> >> >> kernel; netdev@vger.kernel.org
>> >> >> Subject: Re: [Xen-devel] Xen-unstable Linux 3.14-rc3 and 3.13 Network
>> >> >> troubles "bisected"
>> >> >>
>> >> >>
>> >> >> Wednesday, March 26, 2014, 3:44:42 PM, you wrote:
>> >> >>
>> >> >> >> -----Original Message-----
>> >> >> >> From: Sander Eikelenboom [mailto:linux@eikelenboom.it]
>> >> >> >> Sent: 26 March 2014 11:11
>> >> >> >> To: Paul Durrant
>> >> >> >> Cc: Wei Liu; annie li; Zoltan Kiss; xen-devel@lists.xen.org; Ian
>> Campbell;
>> >> >> linux-
>> >> >> >> kernel; netdev@vger.kernel.org
>> >> >> >> Subject: Re: [Xen-devel] Xen-unstable Linux 3.14-rc3 and 3.13
>> Network
>> >> >> >> troubles "bisected"
>> >> >> >>
>> >> >> >> Paul,
>> >> >> >>
>> >> >> >> You have been awfully silent for this whole thread while this is a
>> >> >> regression
>> >> >> >> caused by a patch of you
>> >> >> >> (ca2f09f2b2c6c25047cfc545d057c4edfcfe561c as clearly stated much
>> >> earlier
>> >> >> in
>> >> >> >> this thread).
>> >> >> >>
>> >> >>
>> >> >> > Sorry, I've been distracted...
>> >> >>
>> >> >> >> The commit messages states:
>> >> >> >> "net_rx_action() is the place where we could do with an accurate
>> >> >> >> predicition but,
>> >> >> >> since that has proven tricky to calculate, a cheap worse-case (but
>> not
>> >> >> too
>> >> >> >> bad)
>> >> >> >> estimate is all we really need since the only thing we *must*
>> prevent
>> >> is
>> >> >> >> xenvif_gop_skb()
>> >> >> >> consuming more slots than are available."
>> >> >> >>
>> >> >> >> Your "worst-case" calculation stated in the commit message is
>> clearly
>> >> not
>> >> >> the
>> >> >> >> worst case,
>> >> >> >> since it doesn't take calls to "get_next_rx_buffer" into account