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From: "Jan Beulich" <JBeulich@suse.com>
To: xen-devel <xen-devel@lists.xenproject.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>,
	Roger Pau Monne <roger.pau@citrix.com>,
	Wei Liu <wei.liu2@citrix.com>,
	Igor Druzhinin <igor.druzhinin@citrix.com>
Subject: Re: [PATCH RFC 1/9] x86/IRQ: deal with move-in-progress state in fixup_irqs()
Date: Mon, 29 Apr 2019 07:08:19 -0600	[thread overview]
Message-ID: <5CC6F7430200007800229FBA@prv1-mh.provo.novell.com> (raw)
In-Reply-To: <5CC6F4270200007800229FA8@prv1-mh.provo.novell.com>

>>> On 29.04.19 at 14:55, <JBeulich@suse.com> wrote:
>>>> On 29.04.19 at 13:22, <JBeulich@suse.com> wrote:
>> RFC: I've seen the new ASSERT() in irq_move_cleanup_interrupt() trigger.
>>      I'm pretty sure that this assertion triggering means something else
>>      is wrong, and has been even prior to this change (adding the
>>      assertion without any of the other changes here should be valid in
>>      my understanding).
> 
> So I think what is missing is updating of vector_irq ...
> 
>> @@ -2391,6 +2401,24 @@ void fixup_irqs(const cpumask_t *mask, b
>>              continue;
>>          }
>>  
>> +        /*
>> +         * In order for the affinity adjustment below to be successful, we
>> +         * need __assign_irq_vector() to succeed. This in particular means
>> +         * clearing desc->arch.move_in_progress if this would otherwise
>> +         * prevent the function from succeeding. Since there's no way for the
>> +         * flag to get cleared anymore when there's no possible destination
>> +         * left (the only possibility then would be the IRQs enabled window
>> +         * after this loop), there's then also no race with us doing it here.
>> +         *
>> +         * Therefore the logic here and there need to remain in sync.
>> +         */
>> +        if ( desc->arch.move_in_progress &&
>> +             !cpumask_intersects(mask, desc->arch.cpu_mask) )
>> +        {
>> +            release_old_vec(desc);
>> +            desc->arch.move_in_progress = 0;
>> +        }
> 
> ... here and in the somewhat similar logic patch 2 inserts a few lines
> up. I'm about to try this out, but given how rarely I've seen the
> problem this will take a while to feel confident (if, of course, it helps
> in the first place).

Actually no, the 2nd patch doesn't need any change - the code
added there only deals with CPUs already marked offline.

Jan



_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

WARNING: multiple messages have this Message-ID (diff)
From: "Jan Beulich" <JBeulich@suse.com>
To: "xen-devel" <xen-devel@lists.xenproject.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>,
	Roger Pau Monne <roger.pau@citrix.com>,
	Wei Liu <wei.liu2@citrix.com>,
	Igor Druzhinin <igor.druzhinin@citrix.com>
Subject: Re: [Xen-devel] [PATCH RFC 1/9] x86/IRQ: deal with move-in-progress state in fixup_irqs()
Date: Mon, 29 Apr 2019 07:08:19 -0600	[thread overview]
Message-ID: <5CC6F7430200007800229FBA@prv1-mh.provo.novell.com> (raw)
Message-ID: <20190429130819.hBgTY1WqTfibs3W-gdng5Nmo5q7Iuwd1WjrLwRbVkVE@z> (raw)
In-Reply-To: <5CC6F4270200007800229FA8@prv1-mh.provo.novell.com>

>>> On 29.04.19 at 14:55, <JBeulich@suse.com> wrote:
>>>> On 29.04.19 at 13:22, <JBeulich@suse.com> wrote:
>> RFC: I've seen the new ASSERT() in irq_move_cleanup_interrupt() trigger.
>>      I'm pretty sure that this assertion triggering means something else
>>      is wrong, and has been even prior to this change (adding the
>>      assertion without any of the other changes here should be valid in
>>      my understanding).
> 
> So I think what is missing is updating of vector_irq ...
> 
>> @@ -2391,6 +2401,24 @@ void fixup_irqs(const cpumask_t *mask, b
>>              continue;
>>          }
>>  
>> +        /*
>> +         * In order for the affinity adjustment below to be successful, we
>> +         * need __assign_irq_vector() to succeed. This in particular means
>> +         * clearing desc->arch.move_in_progress if this would otherwise
>> +         * prevent the function from succeeding. Since there's no way for the
>> +         * flag to get cleared anymore when there's no possible destination
>> +         * left (the only possibility then would be the IRQs enabled window
>> +         * after this loop), there's then also no race with us doing it here.
>> +         *
>> +         * Therefore the logic here and there need to remain in sync.
>> +         */
>> +        if ( desc->arch.move_in_progress &&
>> +             !cpumask_intersects(mask, desc->arch.cpu_mask) )
>> +        {
>> +            release_old_vec(desc);
>> +            desc->arch.move_in_progress = 0;
>> +        }
> 
> ... here and in the somewhat similar logic patch 2 inserts a few lines
> up. I'm about to try this out, but given how rarely I've seen the
> problem this will take a while to feel confident (if, of course, it helps
> in the first place).

Actually no, the 2nd patch doesn't need any change - the code
added there only deals with CPUs already marked offline.

Jan



_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

  reply	other threads:[~2019-04-29 13:08 UTC|newest]

Thread overview: 196+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-29 11:16 [PATCH 0/9] x86: IRQ management adjustments Jan Beulich
2019-04-29 11:16 ` [Xen-devel] " Jan Beulich
2019-04-29 11:22 ` [PATCH RFC 1/9] x86/IRQ: deal with move-in-progress state in fixup_irqs() Jan Beulich
2019-04-29 11:22   ` [Xen-devel] " Jan Beulich
2019-04-29 12:55   ` Jan Beulich
2019-04-29 12:55     ` [Xen-devel] " Jan Beulich
2019-04-29 13:08     ` Jan Beulich [this message]
2019-04-29 13:08       ` Jan Beulich
2019-04-29 11:23 ` [PATCH 2/9] x86/IRQ: deal with move cleanup count " Jan Beulich
2019-04-29 11:23   ` [Xen-devel] " Jan Beulich
2019-05-03 15:21   ` Roger Pau Monné
2019-05-03 15:21     ` [Xen-devel] " Roger Pau Monné
2019-05-06  7:44     ` Jan Beulich
2019-05-06  7:44       ` [Xen-devel] " Jan Beulich
2019-05-07  7:28     ` Jan Beulich
2019-05-07  7:28       ` [Xen-devel] " Jan Beulich
2019-05-07  8:12       ` Roger Pau Monné
2019-05-07  8:12         ` [Xen-devel] " Roger Pau Monné
2019-05-07  9:28         ` Jan Beulich
2019-05-07  9:28           ` [Xen-devel] " Jan Beulich
2019-04-29 11:23 ` [PATCH 3/9] x86/IRQ: improve dump_irqs() Jan Beulich
2019-04-29 11:23   ` [Xen-devel] " Jan Beulich
2019-05-03 15:43   ` Roger Pau Monné
2019-05-03 15:43     ` [Xen-devel] " Roger Pau Monné
2019-05-06  8:06     ` Jan Beulich
2019-05-06  8:06       ` [Xen-devel] " Jan Beulich
2019-04-29 11:24 ` [PATCH 4/9] x86/IRQ: desc->affinity should strictly represent the requested value Jan Beulich
2019-04-29 11:24   ` [Xen-devel] " Jan Beulich
2019-05-03 16:21   ` Roger Pau Monné
2019-05-03 16:21     ` [Xen-devel] " Roger Pau Monné
2019-05-06  8:14     ` Jan Beulich
2019-05-06  8:14       ` [Xen-devel] " Jan Beulich
2019-04-29 11:25 ` [PATCH 5/9] x86/IRQ: fix locking around vector management Jan Beulich
2019-04-29 11:25   ` [Xen-devel] " Jan Beulich
2019-05-06 11:48   ` Roger Pau Monné
2019-05-06 11:48     ` [Xen-devel] " Roger Pau Monné
2019-05-06 13:06     ` Jan Beulich
2019-05-06 13:06       ` [Xen-devel] " Jan Beulich
2019-04-29 11:25 ` [PATCH 6/9] x86/IRQ: reduce unused space in struct arch_irq_desc Jan Beulich
2019-04-29 11:25   ` [Xen-devel] " Jan Beulich
2019-04-29 11:46   ` Andrew Cooper
2019-04-29 11:46     ` [Xen-devel] " Andrew Cooper
2019-04-29 11:26 ` [PATCH 7/9] x86/IRQ: drop redundant cpumask_empty() from move_masked_irq() Jan Beulich
2019-04-29 11:26   ` [Xen-devel] " Jan Beulich
2019-05-06 13:39   ` Roger Pau Monné
2019-05-06 13:39     ` [Xen-devel] " Roger Pau Monné
2019-04-29 11:26 ` [PATCH 8/9] x86/IRQ: make fixup_irqs() skip unconnected internally used interrupts Jan Beulich
2019-04-29 11:26   ` [Xen-devel] " Jan Beulich
2019-05-06 13:52   ` Roger Pau Monné
2019-05-06 13:52     ` [Xen-devel] " Roger Pau Monné
2019-05-06 14:25     ` Jan Beulich
2019-05-06 14:25       ` [Xen-devel] " Jan Beulich
2019-05-06 14:37       ` Roger Pau Monné
2019-05-06 14:37         ` [Xen-devel] " Roger Pau Monné
2019-04-29 11:27 ` [PATCH 9/9] x86/IO-APIC: drop an unused variable from setup_IO_APIC_irqs() Jan Beulich
2019-04-29 11:27   ` [Xen-devel] " Jan Beulich
2019-04-29 11:40   ` Andrew Cooper
2019-04-29 11:40     ` [Xen-devel] " Andrew Cooper
2019-04-29 15:40 ` [PATCH v1b 1/9] x86/IRQ: deal with move-in-progress state in fixup_irqs() Jan Beulich
2019-04-29 15:40   ` [Xen-devel] " Jan Beulich
2019-05-03  9:19   ` Roger Pau Monné
2019-05-03  9:19     ` [Xen-devel] " Roger Pau Monné
2019-05-03 14:10     ` Jan Beulich
2019-05-03 14:10       ` [Xen-devel] " Jan Beulich
2019-05-06  7:15       ` Jan Beulich
2019-05-06  7:15         ` [Xen-devel] " Jan Beulich
2019-05-06 14:28         ` Roger Pau Monné
2019-05-06 14:28           ` [Xen-devel] " Roger Pau Monné
2019-05-06 15:00           ` Jan Beulich
2019-05-06 15:00             ` [Xen-devel] " Jan Beulich
2019-05-08 12:59 ` [PATCH v2 00/12] x86: IRQ management adjustments Jan Beulich
2019-05-08 12:59   ` [Xen-devel] " Jan Beulich
2019-05-08 13:03   ` [PATCH v2 01/12] x86/IRQ: deal with move-in-progress state in fixup_irqs() Jan Beulich
2019-05-08 13:03     ` [Xen-devel] " Jan Beulich
2019-05-13  9:04     ` Roger Pau Monné
2019-05-13  9:04       ` [Xen-devel] " Roger Pau Monné
2019-05-13  9:09       ` Jan Beulich
2019-05-13  9:09         ` [Xen-devel] " Jan Beulich
2019-05-08 13:03   ` [PATCH v2 02/12] x86/IRQ: deal with move cleanup count " Jan Beulich
2019-05-08 13:03     ` [Xen-devel] " Jan Beulich
2019-05-08 13:07   ` [PATCH v2 03/12] x86/IRQ: avoid UB (or worse) in trace_irq_mask() Jan Beulich
2019-05-08 13:07     ` [Xen-devel] " Jan Beulich
2019-05-13  9:08     ` Roger Pau Monné
2019-05-13  9:08       ` [Xen-devel] " Roger Pau Monné
2019-05-13 10:42     ` George Dunlap
2019-05-13 10:42       ` [Xen-devel] " George Dunlap
2019-05-13 12:05       ` Jan Beulich
2019-05-13 12:05         ` [Xen-devel] " Jan Beulich
2019-05-08 13:08   ` [PATCH v2 04/12] x86/IRQ: improve dump_irqs() Jan Beulich
2019-05-08 13:08     ` [Xen-devel] " Jan Beulich
2019-05-08 13:09   ` [PATCH v2 05/12] x86/IRQ: desc->affinity should strictly represent the requested value Jan Beulich
2019-05-08 13:09     ` [Xen-devel] " Jan Beulich
2019-05-08 13:10   ` [PATCH v2 06/12] x86/IRQ: consolidate use of ->arch.cpu_mask Jan Beulich
2019-05-08 13:10     ` [Xen-devel] " Jan Beulich
2019-05-13 11:32     ` Roger Pau Monné
2019-05-13 11:32       ` [Xen-devel] " Roger Pau Monné
2019-05-13 15:21       ` Jan Beulich
2019-05-13 15:21         ` [Xen-devel] " Jan Beulich
2019-05-08 13:10   ` [PATCH v2 07/12] x86/IRQ: fix locking around vector management Jan Beulich
2019-05-08 13:10     ` [Xen-devel] " Jan Beulich
2019-05-08 13:16     ` Jan Beulich
2019-05-08 13:16       ` [Xen-devel] " Jan Beulich
2019-05-11  0:11       ` Tian, Kevin
2019-05-11  0:11         ` [Xen-devel] " Tian, Kevin
2019-05-13 13:48     ` Roger Pau Monné
2019-05-13 13:48       ` [Xen-devel] " Roger Pau Monné
2019-05-13 14:19       ` Jan Beulich
2019-05-13 14:19         ` [Xen-devel] " Jan Beulich
2019-05-13 14:45         ` Roger Pau Monné
2019-05-13 14:45           ` [Xen-devel] " Roger Pau Monné
2019-05-13 15:05           ` Jan Beulich
2019-05-13 15:05             ` [Xen-devel] " Jan Beulich
2019-05-08 13:11   ` [PATCH v2 08/12] x86/IRQs: correct/tighten vector check in _clear_irq_vector() Jan Beulich
2019-05-08 13:11     ` [Xen-devel] " Jan Beulich
2019-05-13 14:01     ` Roger Pau Monné
2019-05-13 14:01       ` [Xen-devel] " Roger Pau Monné
2019-05-08 13:12   ` [PATCH v2 09/12] x86/IRQ: make fixup_irqs() skip unconnected internally used interrupts Jan Beulich
2019-05-08 13:12     ` [Xen-devel] " Jan Beulich
2019-05-08 13:13   ` [PATCH v2 10/12] x86/IRQ: reduce unused space in struct arch_irq_desc Jan Beulich
2019-05-08 13:13     ` [Xen-devel] " Jan Beulich
2019-05-08 13:13   ` [PATCH v2 11/12] x86/IRQ: drop redundant cpumask_empty() from move_masked_irq() Jan Beulich
2019-05-08 13:13     ` [Xen-devel] " Jan Beulich
2019-05-08 13:14   ` [PATCH v2 12/12] x86/IRQ: simplify and rename pirq_acktype() Jan Beulich
2019-05-08 13:14     ` [Xen-devel] " Jan Beulich
2019-05-13 14:14     ` Roger Pau Monné
2019-05-13 14:14       ` [Xen-devel] " Roger Pau Monné
2019-05-17 10:39 ` [PATCH v3 00/15] x86: IRQ management adjustments Jan Beulich
2019-05-17 10:39   ` [Xen-devel] " Jan Beulich
2019-05-17 10:44   ` [PATCH v3 01/15] x86/IRQ: deal with move-in-progress state in fixup_irqs() Jan Beulich
2019-05-17 10:44     ` [Xen-devel] " Jan Beulich
2019-07-03 15:39     ` Andrew Cooper
2019-07-04  9:32       ` Jan Beulich
2019-05-17 10:45   ` [PATCH v3 02/15] x86/IRQ: deal with move cleanup count " Jan Beulich
2019-05-17 10:45     ` [Xen-devel] " Jan Beulich
2019-07-03 16:32     ` Andrew Cooper
2019-05-17 10:46   ` [PATCH v3 03/15] x86/IRQ: improve dump_irqs() Jan Beulich
2019-05-17 10:46     ` [Xen-devel] " Jan Beulich
2019-07-03 16:39     ` Andrew Cooper
2019-05-17 10:46   ` [PATCH v3 04/15] x86/IRQ: desc->affinity should strictly represent the requested value Jan Beulich
2019-05-17 10:46     ` [Xen-devel] " Jan Beulich
2019-07-03 17:58     ` Andrew Cooper
2019-07-04  9:37       ` Jan Beulich
2019-05-17 10:47   ` [PATCH v3 05/15] x86/IRQ: consolidate use of ->arch.cpu_mask Jan Beulich
2019-05-17 10:47     ` [Xen-devel] " Jan Beulich
2019-07-03 18:07     ` Andrew Cooper
2019-05-17 10:47   ` [PATCH v3 06/15] x86/IRQ: fix locking around vector management Jan Beulich
2019-05-17 10:47     ` [Xen-devel] " Jan Beulich
2019-07-03 18:23     ` Andrew Cooper
2019-07-04  9:54       ` Jan Beulich
2019-05-17 10:48   ` [PATCH v3 07/15] x86/IRQ: target online CPUs when binding guest IRQ Jan Beulich
2019-05-17 10:48     ` [Xen-devel] " Jan Beulich
2019-05-20 11:40     ` Roger Pau Monné
2019-05-20 11:40       ` [Xen-devel] " Roger Pau Monné
2019-05-20 15:17       ` Jan Beulich
2019-05-20 15:17         ` [Xen-devel] " Jan Beulich
2019-05-22  9:41         ` Roger Pau Monné
2019-05-22  9:41           ` [Xen-devel] " Roger Pau Monné
2019-07-03 18:30     ` Andrew Cooper
2019-05-17 10:49   ` [PATCH v3 08/15] x86/IRQs: correct/tighten vector check in _clear_irq_vector() Jan Beulich
2019-05-17 10:49     ` [Xen-devel] " Jan Beulich
2019-07-03 18:31     ` Andrew Cooper
2019-05-17 10:49   ` [PATCH v3 09/15] x86/IRQ: make fixup_irqs() skip unconnected internally used interrupts Jan Beulich
2019-05-17 10:49     ` [Xen-devel] " Jan Beulich
2019-07-03 18:36     ` Andrew Cooper
2019-05-17 10:50   ` [PATCH v3 10/15] x86/IRQ: drop redundant cpumask_empty() from move_masked_irq() Jan Beulich
2019-05-17 10:50     ` [Xen-devel] " Jan Beulich
2019-07-03 18:38     ` Andrew Cooper
2019-05-17 10:51   ` [PATCH v3 11/15] x86/IRQ: simplify and rename pirq_acktype() Jan Beulich
2019-05-17 10:51     ` [Xen-devel] " Jan Beulich
2019-07-03 18:39     ` Andrew Cooper
2019-05-17 10:51   ` [PATCH v3 12/15] x86/IRQ: add explicit tracing-enabled check to trace_irq_mask() Jan Beulich
2019-05-17 10:51     ` [Xen-devel] " Jan Beulich
2019-05-20 11:46     ` Roger Pau Monné
2019-05-20 11:46       ` [Xen-devel] " Roger Pau Monné
2019-07-03 18:41     ` Andrew Cooper
2019-07-04 10:01       ` Jan Beulich
2019-05-17 10:52   ` [PATCH v3 13/15] x86/IRQ: tighten vector checks Jan Beulich
2019-05-17 10:52     ` [Xen-devel] " Jan Beulich
2019-05-20 14:04     ` Roger Pau Monné
2019-05-20 14:04       ` [Xen-devel] " Roger Pau Monné
2019-05-20 15:26       ` Jan Beulich
2019-05-20 15:26         ` [Xen-devel] " Jan Beulich
2019-05-22 16:42         ` Roger Pau Monné
2019-05-22 16:42           ` [Xen-devel] " Roger Pau Monné
2019-05-23  8:36           ` Jan Beulich
2019-05-23  8:36             ` [Xen-devel] " Jan Beulich
2019-07-03 18:42     ` Andrew Cooper
2019-05-17 10:52   ` [PATCH v3 14/15] x86/IRQ: eliminate some on-stack cpumask_t instances Jan Beulich
2019-05-17 10:52     ` [Xen-devel] " Jan Beulich
2019-05-20 14:22     ` Roger Pau Monné
2019-05-20 14:22       ` [Xen-devel] " Roger Pau Monné
2019-07-03 18:44       ` Andrew Cooper
2019-07-04 10:04         ` Jan Beulich
2019-05-17 10:53   ` [PATCH v3 15/15] x86/IRQ: move {,_}clear_irq_vector() Jan Beulich
2019-05-17 10:53     ` [Xen-devel] " Jan Beulich
2019-07-03 18:45     ` [Xen-devel] [PATCH v3 15/15] x86/IRQ: move {, _}clear_irq_vector() Andrew Cooper

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