From: "Roger Pau Monné" <roger.pau@citrix.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
Igor Druzhinin <igor.druzhinin@citrix.com>,
Wei Liu <wei.liu2@citrix.com>,
Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [Xen-devel] [PATCH v1b 1/9] x86/IRQ: deal with move-in-progress state in fixup_irqs()
Date: Fri, 3 May 2019 11:19:05 +0200 [thread overview]
Message-ID: <20190503091905.2levs75dxln4rhiw@Air-de-Roger> (raw)
Message-ID: <20190503091905.0-mglvnAMaNxFhLyDux1ct_u7fT8-JV2jMA4dGqr7aI@z> (raw)
In-Reply-To: <5CC71ADE020000780022A1B7@prv1-mh.provo.novell.com>
On Mon, Apr 29, 2019 at 09:40:14AM -0600, Jan Beulich wrote:
> The flag being set may prevent affinity changes, as these often imply
> assignment of a new vector. When there's no possible destination left
> for the IRQ, the clearing of the flag needs to happen right from
> fixup_irqs().
>
> Additionally _assign_irq_vector() needs to avoid setting the flag when
> there's no online CPU left in what gets put into ->arch.old_cpu_mask.
> The old vector can be released right away in this case.
>
> Also extend the log message about broken affinity to include the new
> affinity as well, allowing to notice issues with affinity changes not
> actually having taken place. Swap the if/else-if order there at the
> same time to reduce the amount of conditions checked.
>
> At the same time replace two open coded instances of the new helper
> function.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> ---
> v2: Also update vector_irq[] in the code added to fixup_irqs().
>
> --- unstable.orig/xen/arch/x86/irq.c 2019-04-29 17:34:16.726542659 +0200
> +++ unstable/xen/arch/x86/irq.c 2019-04-29 15:05:39.000000000 +0200
> @@ -242,6 +242,20 @@ void destroy_irq(unsigned int irq)
> xfree(action);
> }
>
> +static void release_old_vec(struct irq_desc *desc)
> +{
> + unsigned int vector = desc->arch.old_vector;
> +
> + desc->arch.old_vector = IRQ_VECTOR_UNASSIGNED;
> + cpumask_clear(desc->arch.old_cpu_mask);
> +
> + if ( desc->arch.used_vectors )
Wouldn't it be better to clean the bitmap when vector !=
IRQ_VECTOR_UNASSIGNED?
I haven't checked all the callers, but I don't think it's valid to
call release_old_vec with desc->arch.old_vector ==
IRQ_VECTOR_UNASSIGNED, in which case I would add an ASSERT.
> + {
> + ASSERT(test_bit(vector, desc->arch.used_vectors));
> + clear_bit(vector, desc->arch.used_vectors);
> + }
> +}
> +
> static void __clear_irq_vector(int irq)
> {
> int cpu, vector, old_vector;
> @@ -285,14 +299,7 @@ static void __clear_irq_vector(int irq)
Kind of unrelated, but I think the check at the top of
__clear_irq_vector should be:
BUG_ON(desc->arch.vector == IRQ_VECTOR_UNASSIGNED);
Rather than the current:
BUG_ON(!desc->arch.vector);
There's a lot of logic that would go extremely wrong if vector is -1.
> per_cpu(vector_irq, cpu)[old_vector] = ~irq;
> }
>
> - desc->arch.old_vector = IRQ_VECTOR_UNASSIGNED;
> - cpumask_clear(desc->arch.old_cpu_mask);
> -
> - if ( desc->arch.used_vectors )
> - {
> - ASSERT(test_bit(old_vector, desc->arch.used_vectors));
> - clear_bit(old_vector, desc->arch.used_vectors);
> - }
> + release_old_vec(desc);
>
> desc->arch.move_in_progress = 0;
While there it might be nice to convert move_in_progress to a boolean.
> }
> @@ -517,12 +524,21 @@ next:
> /* Found one! */
> current_vector = vector;
> current_offset = offset;
> - if (old_vector > 0) {
> - desc->arch.move_in_progress = 1;
> - cpumask_copy(desc->arch.old_cpu_mask, desc->arch.cpu_mask);
> +
> + if ( old_vector > 0 )
> + {
> + cpumask_and(desc->arch.old_cpu_mask, desc->arch.cpu_mask,
> + &cpu_online_map);
> desc->arch.old_vector = desc->arch.vector;
> + if ( !cpumask_empty(desc->arch.old_cpu_mask) )
> + desc->arch.move_in_progress = 1;
> + else
> + /* This can happen while offlining a CPU. */
> + release_old_vec(desc);
> }
> +
> trace_irq_mask(TRC_HW_IRQ_ASSIGN_VECTOR, irq, vector, &tmp_mask);
> +
> for_each_cpu(new_cpu, &tmp_mask)
> per_cpu(vector_irq, new_cpu)[vector] = irq;
> desc->arch.vector = vector;
> @@ -691,14 +707,8 @@ void irq_move_cleanup_interrupt(struct c
>
> if ( desc->arch.move_cleanup_count == 0 )
> {
> - desc->arch.old_vector = IRQ_VECTOR_UNASSIGNED;
> - cpumask_clear(desc->arch.old_cpu_mask);
> -
> - if ( desc->arch.used_vectors )
> - {
> - ASSERT(test_bit(vector, desc->arch.used_vectors));
> - clear_bit(vector, desc->arch.used_vectors);
> - }
> + ASSERT(vector == desc->arch.old_vector);
> + release_old_vec(desc);
> }
> unlock:
> spin_unlock(&desc->lock);
> @@ -2391,6 +2401,33 @@ 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) )
> + {
> + unsigned int cpu;
> +
> + cpumask_and(&affinity, desc->arch.old_cpu_mask, &cpu_online_map);
> +
> + spin_lock(&vector_lock);
> + for_each_cpu(cpu, &affinity)
> + per_cpu(vector_irq, cpu)[desc->arch.old_vector] = ~irq;
> + spin_unlock(&vector_lock);
> +
> + release_old_vec(desc);
> + desc->arch.move_in_progress = 0;
> + }
> +
> cpumask_and(&affinity, &affinity, mask);
> if ( cpumask_empty(&affinity) )
> {
> @@ -2409,15 +2446,18 @@ void fixup_irqs(const cpumask_t *mask, b
> if ( desc->handler->enable )
> desc->handler->enable(desc);
>
> + cpumask_copy(&affinity, desc->affinity);
> +
> spin_unlock(&desc->lock);
>
> if ( !verbose )
> continue;
>
> - if ( break_affinity && set_affinity )
> - printk("Broke affinity for irq %i\n", irq);
> - else if ( !set_affinity )
> - printk("Cannot set affinity for irq %i\n", irq);
> + if ( !set_affinity )
> + printk("Cannot set affinity for IRQ%u\n", irq);
> + else if ( break_affinity )
> + printk("Broke affinity for IRQ%u, new: %*pb\n",
> + irq, nr_cpu_ids, &affinity);
I guess it's fine to have those without rate-limiting because
fixup_irqs is only called for admin-triggered actions, so there's no
risk of console flooding.
Thanks, Roger.
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next prev parent reply other threads:[~2019-05-03 9:19 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
2019-04-29 13:08 ` [Xen-devel] " 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 [this message]
2019-05-03 9:19 ` 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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