Re: aacraid: Regression in 4.14.56 with *genirq/affinity: assign vectors to all possible CPUs*

[Greg Kroah-Hartman]

On Tue, Sep 11, 2018 at 12:53:54PM +0200, Paul Menzel wrote:
> Dear Ming, dear Raghava, dear Dave,
> 
> 
> On 08/16/18 19:09, Paul Menzel wrote:
> 
> > On 08/13/18 05:32, Ming Lei wrote:
> >> On Sat, Aug 11, 2018 at 03:50:21PM +0200, Greg Kroah-Hartman wrote:
> >>> On Sat, Aug 11, 2018 at 10:14:18AM +0200, Paul Menzel wrote:
> > 
> >>>> Am 10.08.2018 um 17:55 schrieb Greg Kroah-Hartman:
> >>>>> On Fri, Aug 10, 2018 at 04:11:23PM +0200, Paul Menzel wrote:
> >>>>
> >>>>>> On 08/10/18 15:36, Greg Kroah-Hartman wrote:
> >>>>>>> On Fri, Aug 10, 2018 at 03:21:52PM +0200, Paul Menzel wrote:
> > 
> >>>>>>>> Commit ef86f3a7 (genirq/affinity: assign vectors to all possible CPUs) added
> >>>>>>>> for Linux 4.14.56 causes the aacraid module to not detect the attached devices
> >>>>>>>> anymore on a Dell PowerEdge R720 with two six core 24x E5-2630 @ 2.30GHz.
> >>>>>>>>
> >>>>>>>> ```
> >>>>>>>> $ dmesg | grep raid
> >>>>>>>> [    0.269768] raid6: sse2x1   gen()  7179 MB/s
> >>>>>>>> [    0.290069] raid6: sse2x1   xor()  5636 MB/s
> >>>>>>>> [    0.311068] raid6: sse2x2   gen()  9160 MB/s
> >>>>>>>> [    0.332076] raid6: sse2x2   xor()  6375 MB/s
> >>>>>>>> [    0.353075] raid6: sse2x4   gen() 11164 MB/s
> >>>>>>>> [    0.374064] raid6: sse2x4   xor()  7429 MB/s
> >>>>>>>> [    0.379001] raid6: using algorithm sse2x4 gen() 11164 MB/s
> >>>>>>>> [    0.386001] raid6: .... xor() 7429 MB/s, rmw enabled
> >>>>>>>> [    0.391008] raid6: using ssse3x2 recovery algorithm
> >>>>>>>> [    3.559682] megaraid cmm: 2.20.2.7 (Release Date: Sun Jul 16 00:01:03 EST 2006)
> >>>>>>>> [    3.570061] megaraid: 2.20.5.1 (Release Date: Thu Nov 16 15:32:35 EST 2006)
> >>>>>>>> [   10.725767] Adaptec aacraid driver 1.2.1[50834]-custom
> >>>>>>>> [   10.731724] aacraid 0000:04:00.0: can't disable ASPM; OS doesn't have ASPM control
> >>>>>>>> [   10.743295] aacraid: Comm Interface type3 enabled
> >>>>>>>> $ lspci -nn | grep Adaptec
> >>>>>>>> 04:00.0 Serial Attached SCSI controller [0107]: Adaptec Series 8 12G SAS/PCIe 3 [9005:028d] (rev 01)
> >>>>>>>> 42:00.0 Serial Attached SCSI controller [0107]: Adaptec Smart Storage PQI 12G SAS/PCIe 3 [9005:028f] (rev 01)
> >>>>>>>> ```
> >>>>>>>>
> >>>>>>>> But, it still works with a Dell PowerEdge R715 with two eight core AMD
> >>>>>>>> Opteron 6136, the card below.
> >>>>>>>>
> >>>>>>>> ```
> >>>>>>>> $ lspci -nn | grep Adaptec
> >>>>>>>> 22:00.0 Serial Attached SCSI controller [0107]: Adaptec Series 8 12G SAS/PCIe 3 [9005:028d] (rev 01)
> >>>>>>>> ```
> >>>>>>>>
> >>>>>>>> Reverting the commit fixes the issue.
> >>>>>>>>
> >>>>>>>> commit ef86f3a72adb8a7931f67335560740a7ad696d1d
> >>>>>>>> Author: Christoph Hellwig <hch@xxxxxx>
> >>>>>>>> Date:   Fri Jan 12 10:53:05 2018 +0800
> >>>>>>>>
> >>>>>>>>      genirq/affinity: assign vectors to all possible CPUs
> >>>>>>>>      commit 84676c1f21e8ff54befe985f4f14dc1edc10046b upstream.
> >>>>>>>>      Currently we assign managed interrupt vectors to all present CPUs.  This
> >>>>>>>>      works fine for systems were we only online/offline CPUs.  But in case of
> >>>>>>>>      systems that support physical CPU hotplug (or the virtualized version of
> >>>>>>>>      it) this means the additional CPUs covered for in the ACPI tables or on
> >>>>>>>>      the command line are not catered for.  To fix this we'd either need to
> >>>>>>>>      introduce new hotplug CPU states just for this case, or we can start
> >>>>>>>>      assining vectors to possible but not present CPUs.
> >>>>>>>>      Reported-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> >>>>>>>>      Tested-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> >>>>>>>>      Tested-by: Stefan Haberland <sth@xxxxxxxxxxxxxxxxxx>
> >>>>>>>>      Fixes: 4b855ad37194 ("blk-mq: Create hctx for each present CPU")
> >>>>>>>>      Cc: linux-kernel@xxxxxxxxxxxxxxx
> >>>>>>>>      Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> >>>>>>>>      Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> >>>>>>>>      Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
> >>>>>>>>      Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> >>>>>>>>
> >>>>>>>> The problem doesnât happen with Linux 4.17.11, so there are commits in
> >>>>>>>> Linux master fixing this. Unfortunately, my attempts to find out failed.
> >>>>>>>>
> >>>>>>>> I was able to cherry-pick the three commits below on top of 4.14.62,
> >>>>>>>> but the problem persists.
> >>>>>>>>
> >>>>>>>> 6aba81b5a2f5 genirq/affinity: Don't return with empty affinity masks on error
> >>>>>>>> 355d7ecdea35 scsi: hpsa: fix selection of reply queue
> >>>>>>>> e944e9615741 scsi: virtio_scsi: fix IO hang caused by automatic irq vector affinity
> >>>>>>>>
> >>>>>>>> Trying to cherry-pick the commits below, referencing the commit
> >>>>>>>> in question, gave conflicts.
> >>>>>>>>
> >>>>>>>> 1. adbe552349f2 scsi: megaraid_sas: fix selection of reply queue
> >>>>>>>> 2. d3056812e7df genirq/affinity: Spread irq vectors among present CPUs as far as possible
> >>>>>>>>
> >>>>>>>> To avoid further trial and error with the server with a slow firmware,
> >>>>>>>> do you know what commits should fix the issue?
> >>>>>>>
> >>>>>>> Look at the email on the stable mailing list:
> >>>>>>> 	Subject: Re: Fix for 84676c1f (b5b6e8c8) missing in 4.14.y
> >>>>>>> it should help you out here.
> >>>>>>
> >>>>>> Ah, I didnât see that [1] yet. Also I canât find the original message, and a
> >>>>>> way to reply to that thread. Therefore, here is my reply.
> >>>>>>
> >>>>>>> Can you try the patches listed there?
> >>>>>>
> >>>>>> I tried some of these already without success.
> >>>>>>
> >>>>>> b5b6e8c8d3b4 scsi: virtio_scsi: fix IO hang caused by automatic irq vector affinity
> >>>>>> 2f31115e940c scsi: core: introduce force_blk_mq
> >>>>>> adbe552349f2 scsi: megaraid_sas: fix selection of reply queue
> >>>>>>
> >>>>>> The commit above is already in v4.14.56.
> >>>>>>
> >>>>>> 8b834bff1b73 scsi: hpsa: fix selection of reply queue
> >>>>>>
> >>>>>> The problem persists.
> >>>>>>
> >>>>>> The problem also persists with the state below.
> >>>>>>
> >>>>>> 3528f73a4e5d scsi: core: introduce force_blk_mq
> >>>>>> 16dc4d8215f3 scsi: hpsa: fix selection of reply queue
> >>>>>> f0a7ab12232d scsi: virtio_scsi: fix IO hang caused by automatic irq vector affinity
> >>>>>> 6aba81b5a2f5 genirq/affinity: Don't return with empty affinity masks on error
> >>>>>> 1aa1166eface (tag: v4.14.62, stable/linux-4.14.y) Linux 4.14.62
> >>>>>>
> >>>>>> So, some more commits are necessary.
> >>>>>
> >>>>> Or I revert the original patch here, and the follow-on ones that were
> >>>>> added to "fix" this issue.  I think that might be the better thing
> >>>>> overall here, right?  Have you tried that?
> >>>>
> >>>> Yes, reverting the commit fixed the issue for us. If Christoph or Ming do
> >>>> not have another suggestion for a commit, that would be the way to go.
> >>>
> >>> Christoph or Ming, any ideas here?
> >>>
> >>> In looking at the aacraid code, I don't see anywhere that this is using
> >>> a specific cpu number for queues or anything, but I could be wrong.
> >>> Ideally this should also be failing in 4.17 or 4.18-rc right now as well
> >>> as I don't see anything that would have "fixed" this recently.  Unless
> >>> I'm missing something here?
> >>
> >> From both aac_fib_vector_assign() and aac_src_deliver_message(), looks
> >> every msix vector is used inside driver, so causes this trouble.
> >>
> >> From 84676c1f21e8ff54b (genirq/affinity: assign vectors to all possible CPUs),
> >> actually it should have been since 9a0ef98e18 (genirq/affinity: Assign vectors
> >> to all present CPUs), it isn't guaranteed that one vector can be mapped to
> >> at least one online CPU.
> >>
> >> So it should be fixed in driver by similar approach taken in the
> >> following patches:
> >> 	scsi: hpsa: fix selection of reply queue
> >> 	scsi: megaraid_sas: fix selection of reply queue
> >>
> >> And the reason this issue won't be observed is that the following
> >> patches(merged to v4.17) may avoid this issue, but in theory, the issue
> >> won't be avoided completely by these patches:
> >>
> >> d3056812e7df genirq/affinity: Spread irq vectors among present CPUs as far as possible
> >> 1a2d0914e23a genirq/affinity: Allow irq spreading from a given starting point
> >> b3e6aaa8d94d genirq/affinity: Move actual irq vector spreading into a helper function
> >> 47778f33dcba genirq/affinity: Rename *node_to_possible_cpumask as *node_to_cpumask
> >> 0211e12dd0a5 genirq/affinity: Don't return with empty affinity masks on error
> >>
> >> In short, this issue should have been fixed in upstream aacraid, and the idea
> >> is simple, use the current CPU id to retrieve the msix vector offset, this
> >> way will make sure that the msix vector can be mapped from one online
> >> CPU.
> > 
> > AACRAID folks, are you going to work on that? I looked at the code a bit,
> > and itâll take me some days to understand it and to fix it.
> 
> Unfortunately, there was no reply yet and I wonât be able to fix it any
> time soon. The aacraid driver is still broken in 4.14.68. Reverting the
> *one* mentioned commit fixes the issue.
> 
> Raghava, Dave, are you aware of the issue.

I'm pretty sure this should now be fixed, have you tested this recently?

thanks,

greg k-h