[PATCH] xen: Remove sched_credit_default_yield option

[PATCH] xen: Remove sched_credit_default_yield option

[George Dunlap]

# HG changeset patch
# User George Dunlap <george.dunlap@eu.citrix.com>
# Date 1348499942 -3600
# Node ID e45a63da20e99291fa7e98697a9713aa89b98316
# Parent  7e332fd064fac8d9d1cea904d5236c8d74389194
xen: Remove sched_credit_default_yield option

The sched_credit_default_yield option was added when the behavior of
"SCHEDOP_yield" was changed in 4.1, to allow any users who had
problems to revert to the old behavior.  The new behavior has been in
Xen.org xen since 4.1, and in XenServer even longer, and there is no
evidence of anyone having trouble with it.  Remove the option.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>

diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown
--- a/docs/misc/xen-command-line.markdown
+++ b/docs/misc/xen-command-line.markdown
@@ -726,9 +726,6 @@ Choose the default scheduler.
 ### sched\_credit2\_migrate\_resist
 > `= <integer>`
 
-### sched\_credit\_default\_yield
-> `= <boolean>`
-
 ### sched\_credit\_tslice\_ms
 > `= <integer>`
 
diff --git a/xen/common/sched_credit.c b/xen/common/sched_credit.c
--- a/xen/common/sched_credit.c
+++ b/xen/common/sched_credit.c
@@ -103,8 +103,6 @@
 /*
  * Boot parameters
  */
-static bool_t __read_mostly sched_credit_default_yield;
-boolean_param("sched_credit_default_yield", sched_credit_default_yield);
 static int __read_mostly sched_credit_tslice_ms = CSCHED_DEFAULT_TSLICE_MS;
 integer_param("sched_credit_tslice_ms", sched_credit_tslice_ms);
 
@@ -783,11 +781,8 @@ csched_vcpu_yield(const struct scheduler
 {
     struct csched_vcpu * const sv = CSCHED_VCPU(vc);
 
-    if ( !sched_credit_default_yield )
-    {
-        /* Let the scheduler know that this vcpu is trying to yield */
-        sv->flags |= CSCHED_FLAG_VCPU_YIELD;
-    }
+    /* Let the scheduler know that this vcpu is trying to yield */
+    sv->flags |= CSCHED_FLAG_VCPU_YIELD;
 }
 
 static int

Re: [PATCH] xen: Remove sched_credit_default_yield option

[Ian Jackson]

George Dunlap writes ("[Xen-devel] [PATCH] xen: Remove sched_credit_default_yield option"):
> xen: Remove sched_credit_default_yield option
> 
> The sched_credit_default_yield option was added when the behavior of
> "SCHEDOP_yield" was changed in 4.1, to allow any users who had
> problems to revert to the old behavior.  The new behavior has been in
> Xen.org xen since 4.1, and in XenServer even longer, and there is no
> evidence of anyone having trouble with it.  Remove the option.

Who does this need an ack from ?

Ian.

Re: [PATCH] xen: Remove sched_credit_default_yield option

[George Dunlap]

On Mon, Oct 1, 2012 at 5:51 PM, Ian Jackson <Ian.Jackson@eu.citrix.com> wrote:
> George Dunlap writes ("[Xen-devel] [PATCH] xen: Remove sched_credit_default_yield option"):
>> xen: Remove sched_credit_default_yield option
>>
>> The sched_credit_default_yield option was added when the behavior of
>> "SCHEDOP_yield" was changed in 4.1, to allow any users who had
>> problems to revert to the old behavior.  The new behavior has been in
>> Xen.org xen since 4.1, and in XenServer even longer, and there is no
>> evidence of anyone having trouble with it.  Remove the option.
>
> Who does this need an ack from ?

Jan or Keir are the hypervisor committers.  Normally Keir asks me for
an ack for changes to the scheduler code. :-)

 -George

Re: [PATCH] xen: Remove sched_credit_default_yield option

[Keir Fraser]

On 01/10/2012 17:54, "George Dunlap" <George.Dunlap@eu.citrix.com> wrote:

> On Mon, Oct 1, 2012 at 5:51 PM, Ian Jackson <Ian.Jackson@eu.citrix.com> wrote:
>> George Dunlap writes ("[Xen-devel] [PATCH] xen: Remove
>> sched_credit_default_yield option"):
>>> xen: Remove sched_credit_default_yield option
>>> 
>>> The sched_credit_default_yield option was added when the behavior of
>>> "SCHEDOP_yield" was changed in 4.1, to allow any users who had
>>> problems to revert to the old behavior.  The new behavior has been in
>>> Xen.org xen since 4.1, and in XenServer even longer, and there is no
>>> evidence of anyone having trouble with it.  Remove the option.
>> 
>> Who does this need an ack from ?
> 
> Jan or Keir are the hypervisor committers.  Normally Keir asks me for
> an ack for changes to the scheduler code. :-)

I will apply it. :)

 -- Keir

>  -George