[kvm-unit-tests,2/4] s390x: smp: Only use smp_cpu_setup once
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Message ID 20200114153054.77082-3-frankja@linux.ibm.com
State New
Headers show
Series
  • s390x: smp: Improve smp code and reset checks
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Commit Message

Janosch Frank Jan. 14, 2020, 3:30 p.m. UTC
Let's stop and start instead of using setup to run a function on a
cpu.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 s390x/smp.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

Comments

Thomas Huth Jan. 14, 2020, 4:45 p.m. UTC | #1
On 14/01/2020 16.30, Janosch Frank wrote:
> Let's stop and start instead of using setup to run a function on a
> cpu.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  s390x/smp.c | 19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/s390x/smp.c b/s390x/smp.c
> index 4dee43e..767d167 100644
> --- a/s390x/smp.c
> +++ b/s390x/smp.c
> @@ -47,7 +47,7 @@ static void test_start(void)
>  	psw.mask = extract_psw_mask();
>  	psw.addr = (unsigned long)test_func;
>  
> -	smp_cpu_setup(1, psw);
> +	smp_cpu_start(1, psw);
>  	wait_for_flag();
>  	report(1, "start");
>  }
> @@ -131,9 +131,8 @@ static void test_ecall(void)
>  
>  	report_prefix_push("ecall");
>  	testflag = 0;
> -	smp_cpu_destroy(1);
>  
> -	smp_cpu_setup(1, psw);
> +	smp_cpu_start(1, psw);
>  	wait_for_flag();
>  	testflag = 0;
>  	sigp(1, SIGP_EXTERNAL_CALL, 0, NULL);
> @@ -166,9 +165,8 @@ static void test_emcall(void)
>  
>  	report_prefix_push("emcall");
>  	testflag = 0;
> -	smp_cpu_destroy(1);
>  
> -	smp_cpu_setup(1, psw);
> +	smp_cpu_start(1, psw);
>  	wait_for_flag();
>  	testflag = 0;
>  	sigp(1, SIGP_EMERGENCY_SIGNAL, 0, NULL);
> @@ -186,7 +184,7 @@ static void test_reset_initial(void)
>  	psw.addr = (unsigned long)test_func;
>  
>  	report_prefix_push("reset initial");
> -	smp_cpu_setup(1, psw);
> +	smp_cpu_start(1, psw);
>  
>  	sigp_retry(1, SIGP_INITIAL_CPU_RESET, 0, NULL);
>  	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);
> @@ -217,7 +215,7 @@ static void test_reset(void)
>  	psw.addr = (unsigned long)test_func;
>  
>  	report_prefix_push("cpu reset");
> -	smp_cpu_setup(1, psw);
> +	smp_cpu_start(1, psw);

I think this also fixes a memory leak in case the code did not call
smp_cpu_destroy() inbetween (since smp_cpu_setup() allocates new memory
for the low-core). So as far as I can see, this is a good idea:

Reviewed-by: Thomas Huth <thuth@redhat.com>
Cornelia Huck Jan. 14, 2020, 5:44 p.m. UTC | #2
On Tue, 14 Jan 2020 10:30:51 -0500
Janosch Frank <frankja@linux.ibm.com> wrote:

> Let's stop and start instead of using setup to run a function on a
> cpu.

Looking at the code, we only support active == operating state and
!active == stopped state anyway, right?

> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  s390x/smp.c | 19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Janosch Frank Jan. 15, 2020, 7:50 a.m. UTC | #3
On 1/14/20 5:45 PM, Thomas Huth wrote:
> On 14/01/2020 16.30, Janosch Frank wrote:
>> Let's stop and start instead of using setup to run a function on a
>> cpu.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> ---
>>  s390x/smp.c | 19 ++++++++++++-------
>>  1 file changed, 12 insertions(+), 7 deletions(-)
>>
>> diff --git a/s390x/smp.c b/s390x/smp.c
>> index 4dee43e..767d167 100644
>> --- a/s390x/smp.c
>> +++ b/s390x/smp.c
>> @@ -47,7 +47,7 @@ static void test_start(void)
>>  	psw.mask = extract_psw_mask();
>>  	psw.addr = (unsigned long)test_func;
>>  
>> -	smp_cpu_setup(1, psw);
>> +	smp_cpu_start(1, psw);
>>  	wait_for_flag();
>>  	report(1, "start");
>>  }
>> @@ -131,9 +131,8 @@ static void test_ecall(void)
>>  
>>  	report_prefix_push("ecall");
>>  	testflag = 0;
>> -	smp_cpu_destroy(1);
>>  
>> -	smp_cpu_setup(1, psw);
>> +	smp_cpu_start(1, psw);
>>  	wait_for_flag();
>>  	testflag = 0;
>>  	sigp(1, SIGP_EXTERNAL_CALL, 0, NULL);
>> @@ -166,9 +165,8 @@ static void test_emcall(void)
>>  
>>  	report_prefix_push("emcall");
>>  	testflag = 0;
>> -	smp_cpu_destroy(1);
>>  
>> -	smp_cpu_setup(1, psw);
>> +	smp_cpu_start(1, psw);
>>  	wait_for_flag();
>>  	testflag = 0;
>>  	sigp(1, SIGP_EMERGENCY_SIGNAL, 0, NULL);
>> @@ -186,7 +184,7 @@ static void test_reset_initial(void)
>>  	psw.addr = (unsigned long)test_func;
>>  
>>  	report_prefix_push("reset initial");
>> -	smp_cpu_setup(1, psw);
>> +	smp_cpu_start(1, psw);
>>  
>>  	sigp_retry(1, SIGP_INITIAL_CPU_RESET, 0, NULL);
>>  	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);
>> @@ -217,7 +215,7 @@ static void test_reset(void)
>>  	psw.addr = (unsigned long)test_func;
>>  
>>  	report_prefix_push("cpu reset");
>> -	smp_cpu_setup(1, psw);
>> +	smp_cpu_start(1, psw);
> 
> I think this also fixes a memory leak in case the code did not call
> smp_cpu_destroy() inbetween (since smp_cpu_setup() allocates new memory
> for the low-core). So as far as I can see, this is a good idea:

Well, if the cpu is active, we should just return in the setup function.
But I have another patch in the queue which cleans up lowcore allocation.

> 
> Reviewed-by: Thomas Huth <thuth@redhat.com>
>
Janosch Frank Jan. 15, 2020, 9 a.m. UTC | #4
On 1/14/20 6:44 PM, Cornelia Huck wrote:
> On Tue, 14 Jan 2020 10:30:51 -0500
> Janosch Frank <frankja@linux.ibm.com> wrote:
> 
>> Let's stop and start instead of using setup to run a function on a
>> cpu.
> 
> Looking at the code, we only support active == operating state and
> !active == stopped state anyway, right?

Yes, although I think it might make sense to go over the active tracking
in the future and rather make it a setup tracking. We can always ask via
sigp run if the cpu is running. More stuff to add to the todo...

> 
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> ---
>>  s390x/smp.c | 19 ++++++++++++-------
>>  1 file changed, 12 insertions(+), 7 deletions(-)
> 
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>

Patch
diff mbox series

diff --git a/s390x/smp.c b/s390x/smp.c
index 4dee43e..767d167 100644
--- a/s390x/smp.c
+++ b/s390x/smp.c
@@ -47,7 +47,7 @@  static void test_start(void)
 	psw.mask = extract_psw_mask();
 	psw.addr = (unsigned long)test_func;
 
-	smp_cpu_setup(1, psw);
+	smp_cpu_start(1, psw);
 	wait_for_flag();
 	report(1, "start");
 }
@@ -131,9 +131,8 @@  static void test_ecall(void)
 
 	report_prefix_push("ecall");
 	testflag = 0;
-	smp_cpu_destroy(1);
 
-	smp_cpu_setup(1, psw);
+	smp_cpu_start(1, psw);
 	wait_for_flag();
 	testflag = 0;
 	sigp(1, SIGP_EXTERNAL_CALL, 0, NULL);
@@ -166,9 +165,8 @@  static void test_emcall(void)
 
 	report_prefix_push("emcall");
 	testflag = 0;
-	smp_cpu_destroy(1);
 
-	smp_cpu_setup(1, psw);
+	smp_cpu_start(1, psw);
 	wait_for_flag();
 	testflag = 0;
 	sigp(1, SIGP_EMERGENCY_SIGNAL, 0, NULL);
@@ -186,7 +184,7 @@  static void test_reset_initial(void)
 	psw.addr = (unsigned long)test_func;
 
 	report_prefix_push("reset initial");
-	smp_cpu_setup(1, psw);
+	smp_cpu_start(1, psw);
 
 	sigp_retry(1, SIGP_INITIAL_CPU_RESET, 0, NULL);
 	sigp(1, SIGP_STORE_STATUS_AT_ADDRESS, (uintptr_t)status, NULL);
@@ -217,7 +215,7 @@  static void test_reset(void)
 	psw.addr = (unsigned long)test_func;
 
 	report_prefix_push("cpu reset");
-	smp_cpu_setup(1, psw);
+	smp_cpu_start(1, psw);
 
 	sigp_retry(1, SIGP_CPU_RESET, 0, NULL);
 	report(smp_cpu_stopped(1), "cpu stopped");
@@ -226,6 +224,7 @@  static void test_reset(void)
 
 int main(void)
 {
+	struct psw psw;
 	report_prefix_push("smp");
 
 	if (smp_query_num_cpus() == 1) {
@@ -233,6 +232,12 @@  int main(void)
 		goto done;
 	}
 
+	/* Setting up the cpu to give it a stack and lowcore */
+	psw.mask = extract_psw_mask();
+	psw.addr = (unsigned long)cpu_loop;
+	smp_cpu_setup(1, psw);
+	smp_cpu_stop(1);
+
 	test_start();
 	test_stop();
 	test_stop_store_status();