Re: [Xen-devel] [PATCH v2 3/3] libxc: do some retries in xc_cpupool_removecpu() for EBUSY case

2016-03-01 Thread Juergen Gross 
On 01/03/16 12:58, Wei Liu wrote:
> On Tue, Mar 01, 2016 at 10:02:13AM +0100, Juergen Gross wrote:
>> The hypervisor might return EBUSY when trying to remove a cpu from a
>> cpupool when a domain running in this cpupool has pinned a vcpu
>> temporarily. Do some retries in this case, perhaps the situation
>> cleans up.
>>
>> Signed-off-by: Juergen Gross 
>> ---
>>  tools/libxc/xc_cpupool.c | 13 -
>>  1 file changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/libxc/xc_cpupool.c b/tools/libxc/xc_cpupool.c
>> index c42273e..9f2f95c 100644
>> --- a/tools/libxc/xc_cpupool.c
>> +++ b/tools/libxc/xc_cpupool.c
>> @@ -20,8 +20,11 @@
>>   */
>>  
>>  #include 
>> +#include 
>>  #include "xc_private.h"
>>  
>> +#define LIBXC_BUSY_RETRIES 5
>> +
>>  static int do_sysctl_save(xc_interface *xch, struct xen_sysctl *sysctl)
>>  {
>>  int ret;
>> @@ -141,13 +144,21 @@ int xc_cpupool_removecpu(xc_interface *xch,
>>   uint32_t poolid,
>>   int cpu)
>>  {
>> +unsigned retries;
>> +int err;
>>  DECLARE_SYSCTL;
>>  
>>  sysctl.cmd = XEN_SYSCTL_cpupool_op;
>>  sysctl.u.cpupool_op.op = XEN_SYSCTL_CPUPOOL_OP_RMCPU;
>>  sysctl.u.cpupool_op.cpupool_id = poolid;
>>  sysctl.u.cpupool_op.cpu = (cpu < 0) ? XEN_SYSCTL_CPUPOOL_PAR_ANY : cpu;
>> -return do_sysctl_save(xch, );
>> +for (retries = 0; retries < LIBXC_BUSY_RETRIES; retries++) {
> 
> Libxc coding style requires spaces between ().

Oops, sorry.

> 
>> +err = do_sysctl_save(xch, );
>> +if (err >= 0 || errno != EBUSY)
> 
> Ditto.
> 
>> +break;
>> +sleep(1);
>> +}
>> +return err;
>>  }
>>  
>>  int xc_cpupool_movedomain(xc_interface *xch,


Juergen


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Re: [Xen-devel] [PATCH v2 3/3] libxc: do some retries in xc_cpupool_removecpu() for EBUSY case

2016-03-01 Thread Wei Liu 
On Tue, Mar 01, 2016 at 10:02:13AM +0100, Juergen Gross wrote:
> The hypervisor might return EBUSY when trying to remove a cpu from a
> cpupool when a domain running in this cpupool has pinned a vcpu
> temporarily. Do some retries in this case, perhaps the situation
> cleans up.
> 
> Signed-off-by: Juergen Gross 
> ---
>  tools/libxc/xc_cpupool.c | 13 -
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/libxc/xc_cpupool.c b/tools/libxc/xc_cpupool.c
> index c42273e..9f2f95c 100644
> --- a/tools/libxc/xc_cpupool.c
> +++ b/tools/libxc/xc_cpupool.c
> @@ -20,8 +20,11 @@
>   */
>  
>  #include 
> +#include 
>  #include "xc_private.h"
>  
> +#define LIBXC_BUSY_RETRIES 5
> +
>  static int do_sysctl_save(xc_interface *xch, struct xen_sysctl *sysctl)
>  {
>  int ret;
> @@ -141,13 +144,21 @@ int xc_cpupool_removecpu(xc_interface *xch,
>   uint32_t poolid,
>   int cpu)
>  {
> +unsigned retries;
> +int err;
>  DECLARE_SYSCTL;
>  
>  sysctl.cmd = XEN_SYSCTL_cpupool_op;
>  sysctl.u.cpupool_op.op = XEN_SYSCTL_CPUPOOL_OP_RMCPU;
>  sysctl.u.cpupool_op.cpupool_id = poolid;
>  sysctl.u.cpupool_op.cpu = (cpu < 0) ? XEN_SYSCTL_CPUPOOL_PAR_ANY : cpu;
> -return do_sysctl_save(xch, );
> +for (retries = 0; retries < LIBXC_BUSY_RETRIES; retries++) {

Libxc coding style requires spaces between ().

> +err = do_sysctl_save(xch, );
> +if (err >= 0 || errno != EBUSY)

Ditto.

> +break;
> +sleep(1);
> +}
> +return err;
>  }
>  
>  int xc_cpupool_movedomain(xc_interface *xch,
> -- 
> 2.6.2
> 

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