WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] [PATCH 3 of 3] IRQ: Introduce old_vector to irq_cfg

To: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-devel] [PATCH 3 of 3] IRQ: Introduce old_vector to irq_cfg
From: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Date: Fri, 2 Sep 2011 17:35:16 +0100
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Delivery-date: Fri, 02 Sep 2011 09:39:28 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <patchbomb.1314981313@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <patchbomb.1314981313@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mercurial-patchbomb/1.4.3
Introduce old_vector to irq_cfg with the same principle as
old_cpu_mask.  This removes a brute force loop from
__clear_irq_vector(), and paves the way to correct bitrotten logic
elsewhere in the irq code.

Signed-off-by Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

diff -r cf93a1825d66 -r 1a244d4ca6ac xen/arch/x86/io_apic.c
--- a/xen/arch/x86/io_apic.c    Fri Sep 02 17:33:17 2011 +0100
+++ b/xen/arch/x86/io_apic.c    Fri Sep 02 17:33:17 2011 +0100
@@ -487,11 +487,16 @@ fastcall void smp_irq_move_cleanup_inter
         __get_cpu_var(vector_irq)[vector] = -1;
         cfg->move_cleanup_count--;
 
-        if ( cfg->move_cleanup_count == 0 
-             &&  cfg->used_vectors )
+        if ( cfg->move_cleanup_count == 0 )
         {
-            ASSERT(test_bit(vector, cfg->used_vectors));
-            clear_bit(vector, cfg->used_vectors);
+            cfg->old_vector = -1;
+            cpus_clear(cfg->old_cpu_mask);
+
+            if ( cfg->used_vectors )
+            {
+                ASSERT(test_bit(vector, cfg->used_vectors));
+                clear_bit(vector, cfg->used_vectors);
+            }
         }
 unlock:
         spin_unlock(&desc->lock);
diff -r cf93a1825d66 -r 1a244d4ca6ac xen/arch/x86/irq.c
--- a/xen/arch/x86/irq.c        Fri Sep 02 17:33:17 2011 +0100
+++ b/xen/arch/x86/irq.c        Fri Sep 02 17:33:17 2011 +0100
@@ -211,15 +211,9 @@ static void __clear_irq_vector(int irq)
 
     cpus_and(tmp_mask, cfg->old_cpu_mask, cpu_online_map);
     for_each_cpu_mask(cpu, tmp_mask) {
-        for (vector = FIRST_DYNAMIC_VECTOR; vector <= LAST_DYNAMIC_VECTOR;
-                                vector++) {
-            if (per_cpu(vector_irq, cpu)[vector] != irq)
-                continue;
-            TRACE_3D(TRC_HW_IRQ_MOVE_FINISH,
-                     irq, vector, cpu);
-            per_cpu(vector_irq, cpu)[vector] = -1;
-             break;
-        }
+        ASSERT( per_cpu(vector_irq, cpu)[cfg->old_vector] == irq );
+        TRACE_3D(TRC_HW_IRQ_MOVE_FINISH, irq, vector, cpu);
+        per_cpu(vector_irq, cpu)[vector] = -1;
      }
 
     if ( cfg->used_vectors )
@@ -279,6 +273,7 @@ static void __init init_one_irq_desc(str
 static void __init init_one_irq_cfg(struct irq_cfg *cfg)
 {
     cfg->vector = IRQ_VECTOR_UNASSIGNED;
+    cfg->old_vector = IRQ_VECTOR_UNASSIGNED;
     cpus_clear(cfg->cpu_mask);
     cpus_clear(cfg->old_cpu_mask);
     cfg->used_vectors = NULL;
@@ -418,6 +413,7 @@ next:
         if (old_vector) {
             cfg->move_in_progress = 1;
             cpus_copy(cfg->old_cpu_mask, cfg->cpu_mask);
+            cfg->old_vector = cfg->vector;
         }
         trace_irq_mask(TRC_HW_IRQ_ASSIGN_VECTOR, irq, vector, &tmp_mask);
         for_each_cpu_mask(new_cpu, tmp_mask)
diff -r cf93a1825d66 -r 1a244d4ca6ac xen/include/asm-x86/irq.h
--- a/xen/include/asm-x86/irq.h Fri Sep 02 17:33:17 2011 +0100
+++ b/xen/include/asm-x86/irq.h Fri Sep 02 17:33:17 2011 +0100
@@ -28,7 +28,8 @@ typedef struct {
 } vmask_t;
 
 struct irq_cfg {
-        int  vector;
+        s16 vector;                  /* vector itself is only 8 bits, */
+        s16 old_vector;              /* but we use -1 for unassigned  */
         cpumask_t cpu_mask;
         cpumask_t old_cpu_mask;
         unsigned move_cleanup_count;

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel