[Xen-devel] [PATCH 1/4] xen: sched: avoid dumping duplicate information

[Dario Faggioli <dario.faggioli@xxxxxxxxxx>]

When dumping scheduling information (debug key 'r'), what
we print as 'Idle cpupool' is pretty much the same of what
we print immediately after as 'Cpupool0'. In fact, if there
are no pCPUs outside of any cpupools, it is exactly the
same.

If there are free pCPUs, there is some valuable information,
but still a lot of duplication:

 (XEN) Online Cpus: 0-15
 (XEN) Free Cpus: 8
 (XEN) Idle cpupool:
 (XEN) Scheduler: SMP Credit Scheduler (credit)
 (XEN) info:
 (XEN)   ncpus              = 13
 (XEN)   master             = 0
 (XEN)   credit             = 3900
 (XEN)   credit balance     = 45
 (XEN)   weight             = 1280
 (XEN)   runq_sort          = 11820
 (XEN)   default-weight     = 256
 (XEN)   tslice             = 30ms
 (XEN)   ratelimit          = 1000us
 (XEN)   credits per msec   = 10
 (XEN)   ticks per tslice   = 3
 (XEN)   migration delay    = 0us
 (XEN) idlers: 00000000,00006d29
 (XEN) active vcpus:
 (XEN)     1: [1.7] pri=-1 flags=0 cpu=15 credit=-116 [w=256,cap=0] (84+300) 
{a/i=22/21 m=18+5 (k=0)}
 (XEN)     2: [1.3] pri=0 flags=0 cpu=1 credit=-113 [w=256,cap=0] (87+300) 
{a/i=37/36 m=11+544 (k=0)}
 (XEN)     3: [0.15] pri=-1 flags=0 cpu=4 credit=95 [w=256,cap=0] (210+300) 
{a/i=127/126 m=108+9 (k=0)}
 (XEN)     4: [0.10] pri=-2 flags=0 cpu=12 credit=-287 [w=256,cap=0] (-84+300) 
{a/i=163/162 m=36+568 (k=0)}
 (XEN)     5: [0.7] pri=-2 flags=0 cpu=2 credit=-242 [w=256,cap=0] (-42+300) 
{a/i=129/128 m=16+50 (k=0)}
 (XEN) CPU[08]  sort=5791, sibling=00000000,00000300, core=00000000,0000ff00
 (XEN)   run: [32767.8] pri=-64 flags=0 cpu=8
 (XEN) Cpupool 0:
 (XEN) Cpus: 0-5,10-15
 (XEN) Scheduler: SMP Credit Scheduler (credit)
 (XEN) info:
 (XEN)   ncpus              = 13
 (XEN)   master             = 0
 (XEN)   credit             = 3900
 (XEN)   credit balance     = 45
 (XEN)   weight             = 1280
 (XEN)   runq_sort          = 11820
 (XEN)   default-weight     = 256
 (XEN)   tslice             = 30ms
 (XEN)   ratelimit          = 1000us
 (XEN)   credits per msec   = 10
 (XEN)   ticks per tslice   = 3
 (XEN)   migration delay    = 0us
 (XEN) idlers: 00000000,00006d29
 (XEN) active vcpus:
 (XEN)     1: [1.7] pri=-1 flags=0 cpu=15 credit=-116 [w=256,cap=0] (84+300) 
{a/i=22/21 m=18+5 (k=0)}
 (XEN)     2: [1.3] pri=0 flags=0 cpu=1 credit=-113 [w=256,cap=0] (87+300) 
{a/i=37/36 m=11+544 (k=0)}
 (XEN)     3: [0.15] pri=-1 flags=0 cpu=4 credit=95 [w=256,cap=0] (210+300) 
{a/i=127/126 m=108+9 (k=0)}
 (XEN)     4: [0.10] pri=-2 flags=0 cpu=12 credit=-287 [w=256,cap=0] (-84+300) 
{a/i=163/162 m=36+568 (k=0)}
 (XEN)     5: [0.7] pri=-2 flags=0 cpu=2 credit=-242 [w=256,cap=0] (-42+300) 
{a/i=129/128 m=16+50 (k=0)}
 (XEN) CPU[00]  sort=11801, sibling=00000000,00000003, core=00000000,000000ff
 (XEN)   run: [32767.0] pri=-64 flags=0 cpu=0
 ... ... ...
 (XEN) CPU[15]  sort=11820, sibling=00000000,0000c000, core=00000000,0000ff00
 (XEN)   run: [1.7] pri=-1 flags=0 cpu=15 credit=-116 [w=256,cap=0] (84+300) 
{a/i=22/21 m=18+5 (k=0)}
 (XEN)     1: [32767.15] pri=-64 flags=0 cpu=15
 (XEN) Cpupool 1:
 (XEN) Cpus: 6-7,9
 (XEN) Scheduler: SMP RTDS Scheduler (rtds)
 (XEN) CPU[06]
 (XEN) CPU[07]
 (XEN) CPU[09]

With this change, we get rid of the redundancy, and retain
only the information about the free pCPUs.

(While there, turn a loop index variable from `int' to
`unsigned int' in schedule_dump().)

Signed-off-by: Dario Faggioli <dario.faggioli@xxxxxxxxxx>
---
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: George Dunlap <george.dunlap@xxxxxxxxxxxxx>
---
 xen/common/cpupool.c  |    6 +++---
 xen/common/schedule.c |   18 +++++++++++++-----
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/xen/common/cpupool.c b/xen/common/cpupool.c
index 563864d..5471f93 100644
--- a/xen/common/cpupool.c
+++ b/xen/common/cpupool.c
@@ -728,10 +728,10 @@ void dump_runq(unsigned char key)
 
     print_cpumap("Online Cpus", &cpu_online_map);
     if ( !cpumask_empty(&cpupool_free_cpus) )
+    {
         print_cpumap("Free Cpus", &cpupool_free_cpus);
-
-    printk("Idle cpupool:\n");
-    schedule_dump(NULL);
+        schedule_dump(NULL);
+    }
 
     for_each_cpupool(c)
     {
diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index ecf1545..4ffcd98 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -1473,16 +1473,24 @@ void scheduler_free(struct scheduler *sched)
 
 void schedule_dump(struct cpupool *c)
 {
-    int               i;
+    unsigned int      i;
     struct scheduler *sched;
     cpumask_t        *cpus;
 
     /* Locking, if necessary, must be handled withing each scheduler */
 
-    sched = (c == NULL) ? &ops : c->sched;
-    cpus = cpupool_scheduler_cpumask(c);
-    printk("Scheduler: %s (%s)\n", sched->name, sched->opt_name);
-    SCHED_OP(sched, dump_settings);
+    if ( c != NULL )
+    {
+        sched = c->sched;
+        cpus = c->cpu_valid;
+        printk("Scheduler: %s (%s)\n", sched->name, sched->opt_name);
+        SCHED_OP(sched, dump_settings);
+    }
+    else
+    {
+        sched = &ops;
+        cpus = &cpupool_free_cpus;
+    }
 
     for_each_cpu (i, cpus)
     {


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