[PATCH v4 0/3] switchtest: test different migration types

[PATCH v4 0/3] switchtest: test different migration types

[T. Schaffner]

From: Tobias Schaffner <tobias.schaffner@siemens.com>

Switchtest only tested intended switches between primary and secondary
mode in userland.

Let the rtuo thread also test fault based migrations and migrations that
occur while in kernel mode.

This patch series will also test the bug that was fixed in
829d4d33cb7aa3ee485ad56da6ac0c3b0ce5dbe5

Changes since v3:
- avoid using bool in rttst_swtest_dir struct

Changes since v2:
- Fix style related comments
- Improve commit message of patch 2/3

Changes since v1:
- Squash patches 1 and 2 aswell as 3 and 4
- Call the correct rtswitch_to_xxx function after mode switch in the
  switchtest driver
- Only switch to secondary mode by using a linux syscall or by a call to
  cobalt_thread_relax()

Tobias Schaffner (3):
  switchtest: split the set_mode method
  switchtest: test multiple secondary switch cases
  switchtest: test mode switches while in kernel mode

 include/rtdm/uapi/testing.h         |  14 +++
 kernel/drivers/testing/switchtest.c |   8 ++
 testsuite/switchtest/switchtest.c   | 143 +++++++++++++++++++++-------
 3 files changed, 131 insertions(+), 34 deletions(-)

-- 
2.34.1

[PATCH v4 1/3] switchtest: split the set_mode method

[T. Schaffner]

From: Tobias Schaffner <tobias.schaffner@siemens.com>

Split the set_mode method in separate methods for switching to primary and
secondary mode for improved readability.

This also fixes a wrong evaluation of the mode variable that lead to never
checking the FPU registers in secondary mode.

Signed-off-by: Tobias Schaffner <tobias.schaffner@siemens.com>
---
 testsuite/switchtest/switchtest.c | 58 ++++++++++++++++++++-----------
 1 file changed, 37 insertions(+), 21 deletions(-)

diff --git a/testsuite/switchtest/switchtest.c b/testsuite/switchtest/switchtest.c
index 752671e39..a920ca170 100644
--- a/testsuite/switchtest/switchtest.c
+++ b/testsuite/switchtest/switchtest.c
@@ -297,6 +297,24 @@ static int printout(const char *fmt, ...)
 #define check_fp_result(__expected)	\
 	fp_regs_check(fp_features, __expected, printout)
 
+static void switch_to_primary_mode(void)
+{
+	cobalt_thread_harden();
+	if (cobalt_thread_mode() & (XNRELAX|XNWEAK)) {
+		perror("Switch to primary mode failed.");
+		clean_exit(EXIT_FAILURE);
+	}
+}
+
+static void switch_to_secondary_mode(void)
+{
+	cobalt_thread_relax();
+	if (!(cobalt_thread_mode() & XNRELAX)) {
+		perror("Switch to secondary mode failed.");
+		clean_exit(EXIT_FAILURE);
+	}
+}
+
 static void *sleeper_switcher(void *cookie)
 {
 	struct task_params *param = (struct task_params *) cookie;
@@ -440,18 +458,6 @@ static void *fpu_stress(void *cookie)
 	return NULL;
 }
 
-static void set_mode(const char *prefix, int fd, unsigned mode)
-{
-	switch (mode) {
-	case 1:
-		cobalt_thread_harden();
-		return;
-
-	case 2:
-		cobalt_thread_relax();
-	}
-}
-
 static void *rtup(void *cookie)
 {
 	struct task_params *param = (struct task_params *) cookie;
@@ -475,7 +481,7 @@ static void *rtup(void *cookie)
 	   allowed when suspended in ioctl. */
 	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 
-	set_mode("rtup", fd, 1);
+	switch_to_primary_mode();
 
 	do {
 		err = ioctl(fd, RTTST_RTIOC_SWTEST_PEND, &param->swt);
@@ -556,7 +562,7 @@ static void *rtus(void *cookie)
 	   allowed when suspended in ioctl. */
 	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 
-	set_mode("rtus", fd, 2);
+	switch_to_secondary_mode();
 
 	do {
 		err = ioctl(fd, RTTST_RTIOC_SWTEST_PEND, &param->swt);
@@ -637,8 +643,9 @@ static void *rtuo(void *cookie)
 	   allowed when suspended in ioctl. */
 	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 
-	mode = 1;
-	set_mode("rtuo", fd, mode);
+	switch_to_primary_mode();
+	mode = COBALT_PRIMARY;
+
 	do {
 		err = ioctl(fd, RTTST_RTIOC_SWTEST_PEND, &param->swt);
 	} while (err == -1 && errno == EINTR);
@@ -668,8 +675,10 @@ static void *rtuo(void *cookie)
 		}
 
 		expected = rtsw.from + i * 1000;
-		if ((mode && param->fp & UFPP) || (!mode && param->fp & UFPS))
+		if ((mode == COBALT_PRIMARY && param->fp & UFPP) ||
+		    (mode == COBALT_SECONDARY && param->fp & UFPS)) {
 			fp_regs_set(fp_features, expected);
+		}
 		err = ioctl(fd, RTTST_RTIOC_SWTEST_SWITCH_TO, &rtsw);
 		while (err == -1 && errno == EINTR)
 			err = ioctl(fd, RTTST_RTIOC_SWTEST_PEND, &param->swt);
@@ -682,16 +691,23 @@ static void *rtuo(void *cookie)
 		case -1:
 			clean_exit(EXIT_FAILURE);
 		}
-		if ((mode && param->fp & UFPP) || (!mode && param->fp & UFPS)) {
+
+		if ((mode == COBALT_PRIMARY && param->fp & UFPP) ||
+		    (mode == COBALT_SECONDARY && param->fp & UFPS)) {
 			fp_val = check_fp_result(expected);
 			if (fp_val != expected)
 				handle_bad_fpreg(param->cpu, fp_val);
 		}
 
-		/* Switch mode. */
+		/* Switch between primary and secondary mode */
 		if (i % 3 == 2) {
-			mode = 3 - mode;
-			set_mode("rtuo", fd, mode);
+			if (mode == COBALT_PRIMARY) {
+				switch_to_secondary_mode();
+				mode = COBALT_SECONDARY;
+			} else {
+				switch_to_primary_mode();
+				mode = COBALT_PRIMARY;
+			}
 		}
 
 		if(++i == 4000000)
-- 
2.34.1

[PATCH v4 2/3] switchtest: test multiple secondary switch cases

[T. Schaffner]

From: Tobias Schaffner <tobias.schaffner@siemens.com>

Switches to secondary mode do not only occur when a relax is explicitly
called via the cobalt api but also e.g. when a linux syscall is called in
primary mode.

Also test migrations to secondary mode based on linux syscalls in the rtuo task.

Signed-off-by: Tobias Schaffner <tobias.schaffner@siemens.com>
---
 testsuite/switchtest/switchtest.c | 93 ++++++++++++++++++++++---------
 1 file changed, 67 insertions(+), 26 deletions(-)

diff --git a/testsuite/switchtest/switchtest.c b/testsuite/switchtest/switchtest.c
index a920ca170..e9c552216 100644
--- a/testsuite/switchtest/switchtest.c
+++ b/testsuite/switchtest/switchtest.c
@@ -34,7 +34,9 @@
 #include <semaphore.h>
 #include <setjmp.h>
 #include <getopt.h>
+#include <asm/unistd.h>
 #include <asm/xenomai/features.h>
+#include <asm/xenomai/syscall.h>
 #include <asm/xenomai/uapi/fptest.h>
 #include <cobalt/trace.h>
 #include <rtdm/testing.h>
@@ -75,6 +77,14 @@ typedef enum {
 	UFPS = 4	 /* use the FPU while in secondary mode. */
 } fpflags;
 
+#define TASK_SWITCH_MODES 3
+
+enum task_switch_mode {
+	TASK_SWITCH_PREVIOUS = 0,
+	TASK_SWITCH_NEXT = 1,
+	TASK_SWITCH_MODE = 2
+};
+
 struct cpu_tasks;
 
 struct task_params {
@@ -297,24 +307,57 @@ static int printout(const char *fmt, ...)
 #define check_fp_result(__expected)	\
 	fp_regs_check(fp_features, __expected, printout)
 
-static void switch_to_primary_mode(void)
+static void _assert_primary_mode(char const *calling_func)
 {
-	cobalt_thread_harden();
 	if (cobalt_thread_mode() & (XNRELAX|XNWEAK)) {
-		perror("Switch to primary mode failed.");
+		fprintf(stderr,
+			"Switch to primary mode failed in %s.",
+			calling_func);
 		clean_exit(EXIT_FAILURE);
 	}
 }
 
-static void switch_to_secondary_mode(void)
+#define assert_primary_mode() _assert_primary_mode(__func__)
+
+static void _assert_secondary_mode(char const *calling_func)
 {
-	cobalt_thread_relax();
 	if (!(cobalt_thread_mode() & XNRELAX)) {
-		perror("Switch to secondary mode failed.");
+		fprintf(stderr,
+			"Switch to secondary mode failed in %s.",
+			calling_func);
 		clean_exit(EXIT_FAILURE);
 	}
 }
 
+#define assert_secondary_mode() _assert_secondary_mode(__func__)
+
+static void switch_to_primary_mode(void)
+{
+	cobalt_thread_harden();
+	assert_primary_mode();
+}
+
+static void switch_to_secondary_mode(void)
+{
+	cobalt_thread_relax();
+	assert_secondary_mode();
+}
+
+static void switch_to_secondary_mode_by_using_linux_syscall(void)
+{
+	syscall(__NR_gettid);
+	assert_secondary_mode();
+}
+
+#define SWITCH_FUNC_COUNT 4
+
+static void (*switch_funcs[SWITCH_FUNC_COUNT]) (void) = {
+	switch_to_secondary_mode,
+	switch_to_primary_mode,
+	switch_to_secondary_mode_by_using_linux_syscall,
+	switch_to_primary_mode,
+};
+
 static void *sleeper_switcher(void *cookie)
 {
 	struct task_params *param = (struct task_params *) cookie;
@@ -372,13 +415,13 @@ static void *sleeper_switcher(void *cookie)
 		if (tasks_count == 1)
 			continue;
 
-		switch (i % 3) {
-		case 0:
+		switch (i % TASK_SWITCH_MODES) {
+		case TASK_SWITCH_PREVIOUS:
 			/* to == from means "return to last task" */
 			rtsw.to = rtsw.from;
 			break;
 
-		case 1:
+		case TASK_SWITCH_NEXT:
 			if (++to == rtsw.from)
 				++to;
 			if (to > tasks_count - 1)
@@ -493,13 +536,13 @@ static void *rtup(void *cookie)
 	for (;;) {
 		unsigned expected, fp_val;
 
-		switch (i % 3) {
-		case 0:
+		switch (i % TASK_SWITCH_MODES) {
+		case TASK_SWITCH_PREVIOUS:
 			/* to == from means "return to last task" */
 			rtsw.to = rtsw.from;
 			break;
 
-		case 1:
+		case TASK_SWITCH_NEXT:
 			if (++to == rtsw.from)
 				++to;
 			if (to > tasks_count - 1)
@@ -574,13 +617,13 @@ static void *rtus(void *cookie)
 	for (;;) {
 		unsigned expected, fp_val;
 
-		switch (i % 3) {
-		case 0:
+		switch (i % TASK_SWITCH_MODES) {
+		case TASK_SWITCH_PREVIOUS:
 			/* to == from means "return to last task" */
 			rtsw.to = rtsw.from;
 			break;
 
-		case 1:
+		case TASK_SWITCH_NEXT:
 			if (++to == rtsw.from)
 				++to;
 			if (to > tasks_count - 1)
@@ -656,13 +699,13 @@ static void *rtuo(void *cookie)
 	for (;;) {
 		unsigned expected, fp_val;
 
-		switch (i % 3) {
-		case 0:
+		switch (i % TASK_SWITCH_MODES) {
+		case TASK_SWITCH_PREVIOUS:
 			/* to == from means "return to last task" */
 			rtsw.to = rtsw.from;
 			break;
 
-		case 1:
+		case TASK_SWITCH_NEXT:
 			if (++to == rtsw.from)
 				++to;
 			if (to > tasks_count - 1)
@@ -679,6 +722,7 @@ static void *rtuo(void *cookie)
 		    (mode == COBALT_SECONDARY && param->fp & UFPS)) {
 			fp_regs_set(fp_features, expected);
 		}
+
 		err = ioctl(fd, RTTST_RTIOC_SWTEST_SWITCH_TO, &rtsw);
 		while (err == -1 && errno == EINTR)
 			err = ioctl(fd, RTTST_RTIOC_SWTEST_PEND, &param->swt);
@@ -700,14 +744,11 @@ static void *rtuo(void *cookie)
 		}
 
 		/* Switch between primary and secondary mode */
-		if (i % 3 == 2) {
-			if (mode == COBALT_PRIMARY) {
-				switch_to_secondary_mode();
-				mode = COBALT_SECONDARY;
-			} else {
-				switch_to_primary_mode();
-				mode = COBALT_PRIMARY;
-			}
+		if (i % TASK_SWITCH_MODES == TASK_SWITCH_MODE) {
+			uint switch_iteration = (i / TASK_SWITCH_MODES %
+				SWITCH_FUNC_COUNT);
+			switch_funcs[switch_iteration]();
+			mode = !mode;
 		}
 
 		if(++i == 4000000)
-- 
2.34.1

[PATCH v4 3/3] switchtest: test mode switches while in kernel mode

[T. Schaffner]

From: Tobias Schaffner <tobias.schaffner@siemens.com>

Make the rtuo thread switch between primary and secondary mode while in the
RTTST_RTIOC_SWTEST_SWITCH_TO syscall.

Signed-off-by: Tobias Schaffner <tobias.schaffner@siemens.com>
---
 include/rtdm/uapi/testing.h         | 14 ++++++++++++++
 kernel/drivers/testing/switchtest.c |  8 ++++++++
 testsuite/switchtest/switchtest.c   | 22 ++++++++++++++++++++--
 3 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/include/rtdm/uapi/testing.h b/include/rtdm/uapi/testing.h
index 49f0b7f25..3674ae2de 100644
--- a/include/rtdm/uapi/testing.h
+++ b/include/rtdm/uapi/testing.h
@@ -70,9 +70,23 @@ struct rttst_swtest_task {
 #define RTTST_SWTEST_FPU		0x1
 #define RTTST_SWTEST_FREEZE		0x4 /* Only for kernel-space tasks. */
 
+/**
+ * @brief parameter for the RTTST_RTIOC_SWTEST_SWITCH_TO syscall
+ * @anchor rttst_swtest_dir
+ *
+ * This structure is used to tell the RTTST_RTIOC_SWTEST_SWITCH_TO syscall
+ * which threads should be exchanged and if the mode (primary/secondary) of the
+ * from thread should be switched.
+ */
 struct rttst_swtest_dir {
+	/** Index of the thread that should be replaced. */
 	unsigned int from;
+
+	/** Index of the thread that should run. */
 	unsigned int to;
+
+	/** If the mode should be switched: 0 for no switch, 1 for switch. */
+	unsigned int switch_mode;
 };
 
 struct rttst_swtest_error {
diff --git a/kernel/drivers/testing/switchtest.c b/kernel/drivers/testing/switchtest.c
index b6d0242de..674cdef73 100644
--- a/kernel/drivers/testing/switchtest.c
+++ b/kernel/drivers/testing/switchtest.c
@@ -622,6 +622,10 @@ static int rtswitch_ioctl_nrt(struct rtdm_fd *fd,
 				    arg,
 				    sizeof(fromto));
 
+		if (fromto.switch_mode) {
+			xnthread_harden();
+			return rtswitch_to_rt(ctx, fromto.from, fromto.to);
+		}
 		return rtswitch_to_nrt(ctx, fromto.from, fromto.to);
 
 	case RTTST_RTIOC_SWTEST_GET_SWITCHES_COUNT:
@@ -676,6 +680,10 @@ static int rtswitch_ioctl_rt(struct rtdm_fd *fd,
 				    arg,
 				    sizeof(fromto));
 
+		if (fromto.switch_mode) {
+			xnthread_relax(0, 0);
+			return rtswitch_to_nrt(ctx, fromto.from, fromto.to);
+		}
 		return rtswitch_to_rt(ctx, fromto.from, fromto.to);
 
 	case RTTST_RTIOC_SWTEST_GET_LAST_ERROR:
diff --git a/testsuite/switchtest/switchtest.c b/testsuite/switchtest/switchtest.c
index e9c552216..cb8e956d5 100644
--- a/testsuite/switchtest/switchtest.c
+++ b/testsuite/switchtest/switchtest.c
@@ -358,6 +358,9 @@ static void (*switch_funcs[SWITCH_FUNC_COUNT]) (void) = {
 	switch_to_primary_mode,
 };
 
+/* Switch two times: primary to secondary and back from secondary to primary */
+#define MODE_SWITCHES_KERNEL 2
+
 static void *sleeper_switcher(void *cookie)
 {
 	struct task_params *param = (struct task_params *) cookie;
@@ -377,6 +380,7 @@ static void *sleeper_switcher(void *cookie)
 		clean_exit(EXIT_FAILURE);
 	}
 
+	rtsw.switch_mode = 0;
 	rtsw.from = param->swt.index;
 	to = param->swt.index;
 
@@ -517,6 +521,7 @@ static void *rtup(void *cookie)
 		clean_exit(EXIT_FAILURE);
 	}
 
+	rtsw.switch_mode = 0;
 	rtsw.from = param->swt.index;
 	to = param->swt.index;
 
@@ -598,6 +603,7 @@ static void *rtus(void *cookie)
 		clean_exit(EXIT_FAILURE);
 	}
 
+	rtsw.switch_mode = 0;
 	rtsw.from = param->swt.index;
 	to = param->swt.index;
 
@@ -679,6 +685,7 @@ static void *rtuo(void *cookie)
 		clean_exit(EXIT_FAILURE);
 	}
 
+	rtsw.switch_mode = 0;
 	rtsw.from = param->swt.index;
 	to = param->swt.index;
 
@@ -727,6 +734,9 @@ static void *rtuo(void *cookie)
 		while (err == -1 && errno == EINTR)
 			err = ioctl(fd, RTTST_RTIOC_SWTEST_PEND, &param->swt);
 
+		/* Return to default: do not switch in syscall */
+		rtsw.switch_mode = 0;
+
 		switch (err) {
 		case 0:
 			break;
@@ -746,8 +756,16 @@ static void *rtuo(void *cookie)
 		/* Switch between primary and secondary mode */
 		if (i % TASK_SWITCH_MODES == TASK_SWITCH_MODE) {
 			uint switch_iteration = (i / TASK_SWITCH_MODES %
-				SWITCH_FUNC_COUNT);
-			switch_funcs[switch_iteration]();
+				(SWITCH_FUNC_COUNT + MODE_SWITCHES_KERNEL));
+
+			if (switch_iteration < SWITCH_FUNC_COUNT) {
+				switch_funcs[switch_iteration]();
+			} else {
+				/* Switch mode on next
+				 * RTTST_RTIOC_SWTEST_SWITCH_TO syscall */
+				rtsw.switch_mode = 1;
+			}
+
 			mode = !mode;
 		}
 
-- 
2.34.1

Re: [PATCH v4 3/3] switchtest: test mode switches while in kernel mode

[Jan Kiszka]

On 13.12.22 20:52, T. Schaffner wrote:
> From: Tobias Schaffner <tobias.schaffner@siemens.com>
> 
> Make the rtuo thread switch between primary and secondary mode while in the
> RTTST_RTIOC_SWTEST_SWITCH_TO syscall.
> 
> Signed-off-by: Tobias Schaffner <tobias.schaffner@siemens.com>
> ---
>  include/rtdm/uapi/testing.h         | 14 ++++++++++++++
>  kernel/drivers/testing/switchtest.c |  8 ++++++++
>  testsuite/switchtest/switchtest.c   | 22 ++++++++++++++++++++--
>  3 files changed, 42 insertions(+), 2 deletions(-)
> 
> diff --git a/include/rtdm/uapi/testing.h b/include/rtdm/uapi/testing.h
> index 49f0b7f25..3674ae2de 100644
> --- a/include/rtdm/uapi/testing.h
> +++ b/include/rtdm/uapi/testing.h
> @@ -70,9 +70,23 @@ struct rttst_swtest_task {
>  #define RTTST_SWTEST_FPU		0x1
>  #define RTTST_SWTEST_FREEZE		0x4 /* Only for kernel-space tasks. */
>  
> +/**
> + * @brief parameter for the RTTST_RTIOC_SWTEST_SWITCH_TO syscall
> + * @anchor rttst_swtest_dir
> + *
> + * This structure is used to tell the RTTST_RTIOC_SWTEST_SWITCH_TO syscall
> + * which threads should be exchanged and if the mode (primary/secondary) of the
> + * from thread should be switched.
> + */
>  struct rttst_swtest_dir {
> +	/** Index of the thread that should be replaced. */
>  	unsigned int from;
> +
> +	/** Index of the thread that should run. */
>  	unsigned int to;
> +
> +	/** If the mode should be switched: 0 for no switch, 1 for switch. */
> +	unsigned int switch_mode;
>  };
>  
>  struct rttst_swtest_error {
> diff --git a/kernel/drivers/testing/switchtest.c b/kernel/drivers/testing/switchtest.c
> index b6d0242de..674cdef73 100644
> --- a/kernel/drivers/testing/switchtest.c
> +++ b/kernel/drivers/testing/switchtest.c
> @@ -622,6 +622,10 @@ static int rtswitch_ioctl_nrt(struct rtdm_fd *fd,
>  				    arg,
>  				    sizeof(fromto));
>  
> +		if (fromto.switch_mode) {
> +			xnthread_harden();
> +			return rtswitch_to_rt(ctx, fromto.from, fromto.to);
> +		}
>  		return rtswitch_to_nrt(ctx, fromto.from, fromto.to);
>  
>  	case RTTST_RTIOC_SWTEST_GET_SWITCHES_COUNT:
> @@ -676,6 +680,10 @@ static int rtswitch_ioctl_rt(struct rtdm_fd *fd,
>  				    arg,
>  				    sizeof(fromto));
>  
> +		if (fromto.switch_mode) {
> +			xnthread_relax(0, 0);
> +			return rtswitch_to_nrt(ctx, fromto.from, fromto.to);
> +		}
>  		return rtswitch_to_rt(ctx, fromto.from, fromto.to);
>  
>  	case RTTST_RTIOC_SWTEST_GET_LAST_ERROR:
> diff --git a/testsuite/switchtest/switchtest.c b/testsuite/switchtest/switchtest.c
> index e9c552216..cb8e956d5 100644
> --- a/testsuite/switchtest/switchtest.c
> +++ b/testsuite/switchtest/switchtest.c
> @@ -358,6 +358,9 @@ static void (*switch_funcs[SWITCH_FUNC_COUNT]) (void) = {
>  	switch_to_primary_mode,
>  };
>  
> +/* Switch two times: primary to secondary and back from secondary to primary */
> +#define MODE_SWITCHES_KERNEL 2
> +
>  static void *sleeper_switcher(void *cookie)
>  {
>  	struct task_params *param = (struct task_params *) cookie;
> @@ -377,6 +380,7 @@ static void *sleeper_switcher(void *cookie)
>  		clean_exit(EXIT_FAILURE);
>  	}
>  
> +	rtsw.switch_mode = 0;
>  	rtsw.from = param->swt.index;
>  	to = param->swt.index;
>  
> @@ -517,6 +521,7 @@ static void *rtup(void *cookie)
>  		clean_exit(EXIT_FAILURE);
>  	}
>  
> +	rtsw.switch_mode = 0;
>  	rtsw.from = param->swt.index;
>  	to = param->swt.index;
>  
> @@ -598,6 +603,7 @@ static void *rtus(void *cookie)
>  		clean_exit(EXIT_FAILURE);
>  	}
>  
> +	rtsw.switch_mode = 0;
>  	rtsw.from = param->swt.index;
>  	to = param->swt.index;
>  
> @@ -679,6 +685,7 @@ static void *rtuo(void *cookie)
>  		clean_exit(EXIT_FAILURE);
>  	}
>  
> +	rtsw.switch_mode = 0;
>  	rtsw.from = param->swt.index;
>  	to = param->swt.index;
>  
> @@ -727,6 +734,9 @@ static void *rtuo(void *cookie)
>  		while (err == -1 && errno == EINTR)
>  			err = ioctl(fd, RTTST_RTIOC_SWTEST_PEND, &param->swt);
>  
> +		/* Return to default: do not switch in syscall */
> +		rtsw.switch_mode = 0;
> +
>  		switch (err) {
>  		case 0:
>  			break;
> @@ -746,8 +756,16 @@ static void *rtuo(void *cookie)
>  		/* Switch between primary and secondary mode */
>  		if (i % TASK_SWITCH_MODES == TASK_SWITCH_MODE) {
>  			uint switch_iteration = (i / TASK_SWITCH_MODES %
> -				SWITCH_FUNC_COUNT);
> -			switch_funcs[switch_iteration]();
> +				(SWITCH_FUNC_COUNT + MODE_SWITCHES_KERNEL));
> +
> +			if (switch_iteration < SWITCH_FUNC_COUNT) {
> +				switch_funcs[switch_iteration]();
> +			} else {
> +				/* Switch mode on next
> +				 * RTTST_RTIOC_SWTEST_SWITCH_TO syscall */
> +				rtsw.switch_mode = 1;
> +			}
> +
>  			mode = !mode;
>  		}
>  

Applied this to next now as well (patches 1 and 2 were already via v3 of
the series - I assume they didn't change).

Thanks,
Jan

-- 
Siemens AG, Technology
Competence Center Embedded Linux