MCPM backend for Exynos5420

arch/arm/mach-exynos/mcpm-exynos.c new file +38 -0

+
+       node = of_find_compatible_node(NULL, NULL, "samsung,exynos5420");
+       if (!node)
+               return -ENODEV;
+       of_node_put(node);
+
+       if (!cci_probed())
+               return -ENODEV;
+
+       node = of_find_compatible_node(NULL, NULL,
+                       "samsung,exynos4210-sysram-ns");
+       if (!node)
+               return -ENODEV;
+
+       ns_sram_base_addr = of_iomap(node, 0);
+       of_node_put(node);
+       if (!ns_sram_base_addr) {
+               pr_err("failed to map non-secure iRAM base address\n");
+               return -ENOMEM;
+       }
+
+       /*
+        * To increase the stability of KFC reset we need to program
+        * the PMU SPARE3 register
+        */
+       __raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3);
+
+       exynos_mcpm_usage_count_init();
+
+       ret = mcpm_platform_register(&exynos_power_ops);
+       if (!ret)
+               ret = mcpm_sync_init(exynos_pm_power_up_setup);
+       if (ret) {
+               iounmap(ns_sram_base_addr);
+               return ret;
+       }
+
+       mcpm_smp_set_ops();

arch/arm/mach-exynos/mcpm-exynos.c new file +4 -0

+       return ret;
+}
+
+early_initcall(exynos_mcpm_init);

arch/arm/mach-exynos/regs-pmu.h +3 -1

index f6b68a3..4179f6a 100644
@@ -38,6 +38,7 @@
 #define S5P_INFORM5                            S5P_PMUREG(0x0814)
 #define S5P_INFORM6                            S5P_PMUREG(0x0818)
 #define S5P_INFORM7                            S5P_PMUREG(0x081C)
+#define S5P_PMU_SPARE3                         S5P_PMUREG(0x090C)
 
 #define S5P_ARM_CORE0_LOWPWR                   S5P_PMUREG(0x1000)
 #define S5P_DIS_IRQ_CORE0                      S5P_PMUREG(0x1004)

@@ -322,4 +323,6 @@
 
 #define EXYNOS5_OPTION_USE_RETENTION                           (1 << 4)
 
+#define EXYNOS5420_SWRESET_KFC_SEL                             0x3
+
 #endif /* __ASM_ARCH_REGS_PMU_H */
--

1.7.9.5

On Tue, May 13, 2014 at 12:58:44PM +0100, Abhilash Kesavan wrote:

[...]

arch/arm/mach-exynos/mcpm-exynos.c line 294

Quoted 4 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +4 -0

+static int __init exynos_mcpm_init(void)
+{
+       struct device_node *node;
+       int ret = 0;

There is no point in initializing it to 0.

Quoted 43 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +42 -0

+
+       node = of_find_compatible_node(NULL, NULL, "samsung,exynos5420");
+       if (!node)
+               return -ENODEV;
+       of_node_put(node);
+
+       if (!cci_probed())
+               return -ENODEV;
+
+       node = of_find_compatible_node(NULL, NULL,
+                       "samsung,exynos4210-sysram-ns");
+       if (!node)
+               return -ENODEV;
+
+       ns_sram_base_addr = of_iomap(node, 0);
+       of_node_put(node);
+       if (!ns_sram_base_addr) {
+               pr_err("failed to map non-secure iRAM base address\n");
+               return -ENOMEM;
+       }
+
+       /*
+        * To increase the stability of KFC reset we need to program
+        * the PMU SPARE3 register
+        */
+       __raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3);
+
+       exynos_mcpm_usage_count_init();
+
+       ret = mcpm_platform_register(&exynos_power_ops);
+       if (!ret)
+               ret = mcpm_sync_init(exynos_pm_power_up_setup);
+       if (ret) {
+               iounmap(ns_sram_base_addr);
+               return ret;
+       }
+
+       mcpm_smp_set_ops();
+
+       pr_info("Exynos MCPM support installed\n");
+
+       /*

arch/arm/mach-exynos/mcpm-exynos.c line 342

Quoted 6 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +6 -0

+        * Future entries into the kernel can now go
+        * through the cluster entry vectors.
+        */
+       __raw_writel(virt_to_phys(mcpm_entry_point),
+                       ns_sram_base_addr + MCPM_BOOT_ADDR_OFFSET);
+

ns_sram_base_addr must be unmapped, since it is unused after the write.

Hi Lorenzo,

Quoted 10 lines · Lorenzo Pieralisi

On Tue, May 13, 2014 at 12:58:44PM +0100, Abhilash Kesavan wrote:

[...]

arch/arm/mach-exynos/mcpm-exynos.c line 294

Quoted 4 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +4 -0

+static int __init exynos_mcpm_init(void)
+{
+       struct device_node *node;
+       int ret = 0;

There is no point in initializing it to 0.

OK.

Quoted 43 lines

Quoted 43 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +42 -0

+
+       node = of_find_compatible_node(NULL, NULL, "samsung,exynos5420");
+       if (!node)
+               return -ENODEV;
+       of_node_put(node);
+
+       if (!cci_probed())
+               return -ENODEV;
+
+       node = of_find_compatible_node(NULL, NULL,
+                       "samsung,exynos4210-sysram-ns");
+       if (!node)
+               return -ENODEV;
+
+       ns_sram_base_addr = of_iomap(node, 0);
+       of_node_put(node);
+       if (!ns_sram_base_addr) {
+               pr_err("failed to map non-secure iRAM base address\n");
+               return -ENOMEM;
+       }
+
+       /*
+        * To increase the stability of KFC reset we need to program
+        * the PMU SPARE3 register
+        */
+       __raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3);
+
+       exynos_mcpm_usage_count_init();
+
+       ret = mcpm_platform_register(&exynos_power_ops);
+       if (!ret)
+               ret = mcpm_sync_init(exynos_pm_power_up_setup);
+       if (ret) {
+               iounmap(ns_sram_base_addr);
+               return ret;
+       }
+
+       mcpm_smp_set_ops();
+
+       pr_info("Exynos MCPM support installed\n");
+
+       /*

Quoted 8 lines

arch/arm/mach-exynos/mcpm-exynos.c line 342

Quoted 6 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +6 -0

+        * Future entries into the kernel can now go
+        * through the cluster entry vectors.
+        */
+       __raw_writel(virt_to_phys(mcpm_entry_point),
+                       ns_sram_base_addr + MCPM_BOOT_ADDR_OFFSET);
+

ns_sram_base_addr must be unmapped, since it is unused after the write.

Will unmap.

Regards,
Abhilash
--
To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo at vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html

Quoted 66 lines · Abhilash Kesavan

Hi Lorenzo,

Quoted 10 lines · Lorenzo Pieralisi

On Tue, May 13, 2014 at 12:58:44PM +0100, Abhilash Kesavan wrote:

[...]

arch/arm/mach-exynos/mcpm-exynos.c line 294

Quoted 4 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +4 -0

+static int __init exynos_mcpm_init(void)
+{
+       struct device_node *node;
+       int ret = 0;

There is no point in initializing it to 0.

OK.

Quoted 51 lines

Quoted 39 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +38 -0

+
+       node = of_find_compatible_node(NULL, NULL, "samsung,exynos5420");
+       if (!node)
+               return -ENODEV;
+       of_node_put(node);
+
+       if (!cci_probed())
+               return -ENODEV;
+
+       node = of_find_compatible_node(NULL, NULL,
+                       "samsung,exynos4210-sysram-ns");
+       if (!node)
+               return -ENODEV;
+
+       ns_sram_base_addr = of_iomap(node, 0);
+       of_node_put(node);
+       if (!ns_sram_base_addr) {
+               pr_err("failed to map non-secure iRAM base address\n");
+               return -ENOMEM;
+       }
+
+       /*
+        * To increase the stability of KFC reset we need to program
+        * the PMU SPARE3 register
+        */
+       __raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3);
+
+       exynos_mcpm_usage_count_init();
+
+       ret = mcpm_platform_register(&exynos_power_ops);
+       if (!ret)
+               ret = mcpm_sync_init(exynos_pm_power_up_setup);
+       if (ret) {
+               iounmap(ns_sram_base_addr);
+               return ret;
+       }
+
+       mcpm_smp_set_ops();

arch/arm/mach-exynos/mcpm-exynos.c line 342

Quoted 10 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +10 -0

+
+       pr_info("Exynos MCPM support installed\n");
+
+       /*
+        * Future entries into the kernel can now go
+        * through the cluster entry vectors.
+        */
+       __raw_writel(virt_to_phys(mcpm_entry_point),
+                       ns_sram_base_addr + MCPM_BOOT_ADDR_OFFSET);
+

ns_sram_base_addr must be unmapped, since it is unused after the write.

Quoted 1 line

Will unmap.

This mapping is required in for cpuilde (suspend) to program mcpm_entry before going to suspend.

Quoted 8 lines

Regards,
Abhilash
--
To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo at vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html

--
with warm regards,
Chander Kashyap

Quoted 66 lines · Abhilash Kesavan

Hi Lorenzo,

Quoted 10 lines · Lorenzo Pieralisi

On Tue, May 13, 2014 at 12:58:44PM +0100, Abhilash Kesavan wrote:

[...]

arch/arm/mach-exynos/mcpm-exynos.c line 294

Quoted 4 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +4 -0

+static int __init exynos_mcpm_init(void)
+{
+       struct device_node *node;
+       int ret = 0;

There is no point in initializing it to 0.

OK.

Quoted 51 lines

Quoted 39 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +38 -0

+
+       node = of_find_compatible_node(NULL, NULL, "samsung,exynos5420");
+       if (!node)
+               return -ENODEV;
+       of_node_put(node);
+
+       if (!cci_probed())
+               return -ENODEV;
+
+       node = of_find_compatible_node(NULL, NULL,
+                       "samsung,exynos4210-sysram-ns");
+       if (!node)
+               return -ENODEV;
+
+       ns_sram_base_addr = of_iomap(node, 0);
+       of_node_put(node);
+       if (!ns_sram_base_addr) {
+               pr_err("failed to map non-secure iRAM base address\n");
+               return -ENOMEM;
+       }
+
+       /*
+        * To increase the stability of KFC reset we need to program
+        * the PMU SPARE3 register
+        */
+       __raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3);
+
+       exynos_mcpm_usage_count_init();
+
+       ret = mcpm_platform_register(&exynos_power_ops);
+       if (!ret)
+               ret = mcpm_sync_init(exynos_pm_power_up_setup);
+       if (ret) {
+               iounmap(ns_sram_base_addr);
+               return ret;
+       }
+
+       mcpm_smp_set_ops();

arch/arm/mach-exynos/mcpm-exynos.c line 342

Quoted 10 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +10 -0

+
+       pr_info("Exynos MCPM support installed\n");
+
+       /*
+        * Future entries into the kernel can now go
+        * through the cluster entry vectors.
+        */
+       __raw_writel(virt_to_phys(mcpm_entry_point),
+                       ns_sram_base_addr + MCPM_BOOT_ADDR_OFFSET);
+

ns_sram_base_addr must be unmapped, since it is unused after the write.

Quoted 1 line

Will unmap.

This mapping is required in for cpuilde (suspend) to program mcpm_entry before going to suspend.

Quoted 67 lines · Chander Kashyap

Quoted 66 lines · Abhilash Kesavan

Hi Lorenzo,

Quoted 10 lines · Lorenzo Pieralisi

On Tue, May 13, 2014 at 12:58:44PM +0100, Abhilash Kesavan wrote:

[...]

arch/arm/mach-exynos/mcpm-exynos.c line 294

Quoted 4 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +4 -0

+static int __init exynos_mcpm_init(void)
+{
+       struct device_node *node;
+       int ret = 0;

There is no point in initializing it to 0.

OK.

Quoted 51 lines

Quoted 39 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +38 -0

+
+       node = of_find_compatible_node(NULL, NULL, "samsung,exynos5420");
+       if (!node)
+               return -ENODEV;
+       of_node_put(node);
+
+       if (!cci_probed())
+               return -ENODEV;
+
+       node = of_find_compatible_node(NULL, NULL,
+                       "samsung,exynos4210-sysram-ns");
+       if (!node)
+               return -ENODEV;
+
+       ns_sram_base_addr = of_iomap(node, 0);
+       of_node_put(node);
+       if (!ns_sram_base_addr) {
+               pr_err("failed to map non-secure iRAM base address\n");
+               return -ENOMEM;
+       }
+
+       /*
+        * To increase the stability of KFC reset we need to program
+        * the PMU SPARE3 register
+        */
+       __raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3);
+
+       exynos_mcpm_usage_count_init();
+
+       ret = mcpm_platform_register(&exynos_power_ops);
+       if (!ret)
+               ret = mcpm_sync_init(exynos_pm_power_up_setup);
+       if (ret) {
+               iounmap(ns_sram_base_addr);
+               return ret;
+       }
+
+       mcpm_smp_set_ops();

arch/arm/mach-exynos/mcpm-exynos.c line 342

Quoted 10 lines

arch/arm/mach-exynos/mcpm-exynos.c new file +10 -0

+
+       pr_info("Exynos MCPM support installed\n");
+
+       /*
+        * Future entries into the kernel can now go
+        * through the cluster entry vectors.
+        */
+       __raw_writel(virt_to_phys(mcpm_entry_point),
+                       ns_sram_base_addr + MCPM_BOOT_ADDR_OFFSET);
+

ns_sram_base_addr must be unmapped, since it is unused after the write.

Quoted 4 lines

Quoted 1 line

Will unmap.

This mapping is required in for cpuilde (suspend) to program mcpm_entry before going to suspend.

Why?

Nicolas

Quoted 17 lines · Nicolas Pitre

Quoted 16 lines · Chander Kashyap

Quoted 14 lines · Abhilash Kesavan

Quoted 11 lines · Lorenzo Pieralisi

arch/arm/mach-exynos/mcpm-exynos.c line 342

Quoted 7 lines · Abhilash Kesavan

arch/arm/mach-exynos/mcpm-exynos.c new file +7 -0

+       /*
+        * Future entries into the kernel can now go
+        * through the cluster entry vectors.
+        */
+       __raw_writel(virt_to_phys(mcpm_entry_point),
+                       ns_sram_base_addr + MCPM_BOOT_ADDR_OFFSET);
+

ns_sram_base_addr must be unmapped, since it is unused after the write.

Will unmap.

Quoted 4 lines

Quoted 2 lines

This mapping is required in for cpuilde (suspend) to program mcpm_entry before going to suspend.

Why?

This is required to program the mcpm_entry point address (resume address) after cpuidle exit/fail.

This is v6 of the series adding MCPM backend support for SMP secondary boot and core switching on Samsung's Exynos5420. The patches are based on the mcpm support added for Exynos5420 in the Chromium kernel repository here:
https://chromium.googlesource.com/chromiumos/third_party/kernel-next/+/chromeos-3.8

The patches have been prepared on Kukjin Kim's for-next branch and tested on SMDK5420 EVT1 as well as an exynos5420 based chromebook (peach-pit) using the "/dev/b.L_switcher" user interface. Secondary core boot-up has also been tested on both the boards.

Quoted 9 lines · Abhilash Kesavan

This is v6 of the series adding MCPM backend support for SMP secondary boot and core switching on Samsung's Exynos5420. The patches are based on the mcpm support added for Exynos5420 in the Chromium kernel repository here:
https://chromium.googlesource.com/chromiumos/third_party/kernel-next/+/chromeos-3.8

The patches have been prepared on Kukjin Kim's for-next branch and tested on SMDK5420 EVT1 as well as an exynos5420 based chromebook (peach-pit) using the "/dev/b.L_switcher" user interface. Secondary core boot-up has also been tested on both the boards.

OK... Now it is time for real testing. :-)

The /dev/b.L_switcher interface tests the switcher. Here you really want to hammer the MCPM functionalities and especially your backend code as hard as possible. I therefore recommend the following test script:

---------- >8
#!/bin/bash

echo 0 >/sys/kernel/bL_switcher/active
sleep 1

pids=
for cpu in /sys/devices/system/cpu/cpu?/online; do
{ cpu_nr=${cpu:27:1}

    while true; do
      echo 1 > $cpu 2> /dev/null
      sleep .00$RANDOM
      val1=$(cat $cpu)
      echo 0 > $cpu 2> /dev/null
      sleep .00$RANDOM
      val0=$(cat $cpu)
      [ "$val1" = "1" -a "$val0" = "0" ] && echo -n $cpu_nr
    done

} &
pids="$pids $!"
done

trap "kill $pids; echo" 0 15
wait $pids
---------- >8

Leave this running for a couple hours making sure you see all CPU numbers being printed. The printing order will be random, but each CPU number should continuously appear.

Nicolas

Hi Nicolas,

Quoted 44 lines · Nicolas Pitre

Quoted 9 lines · Abhilash Kesavan

This is v6 of the series adding MCPM backend support for SMP secondary boot and core switching on Samsung's Exynos5420. The patches are based on the mcpm support added for Exynos5420 in the Chromium kernel repository here:
https://chromium.googlesource.com/chromiumos/third_party/kernel-next/+/chromeos-3.8

The patches have been prepared on Kukjin Kim's for-next branch and tested on SMDK5420 EVT1 as well as an exynos5420 based chromebook (peach-pit) using the "/dev/b.L_switcher" user interface. Secondary core boot-up has also been tested on both the boards.

OK... Now it is time for real testing. :-)

The /dev/b.L_switcher interface tests the switcher. Here you really want to hammer the MCPM functionalities and especially your backend code as hard as possible. I therefore recommend the following test script:

---------- >8
#!/bin/bash

echo 0 >/sys/kernel/bL_switcher/active
sleep 1

pids=
for cpu in /sys/devices/system/cpu/cpu?/online; do
{ cpu_nr=${cpu:27:1}

    while true; do
      echo 1 > $cpu 2> /dev/null
      sleep .00$RANDOM
      val1=$(cat $cpu)
      echo 0 > $cpu 2> /dev/null
      sleep .00$RANDOM
      val0=$(cat $cpu)
      [ "$val1" = "1" -a "$val0" = "0" ] && echo -n $cpu_nr
    done

} &
pids="$pids $!"
done

trap "kill $pids; echo" 0 15
wait $pids
---------- >8

Quoted 3 lines

Leave this running for a couple hours making sure you see all CPU numbers being printed. The printing order will be random, but each CPU number should continuously appear.

I tried this script and I get two errors:

1) can't create /sys/devices/system/cpu/cpu//online: nonexistent directory

2) sleep: invalid number '.0026736'

For 1) the cpu number is not being appended. if I give a particular cpu in the script then hotplug in/out works fine.
For 2) a constant msleep 10 works.

Is it OK for me to modify the script to hotplug in/off a randomly chosed core ?

Quoted 2 lines

1) can't create /sys/devices/system/cpu/cpu//online: nonexistent directory

What do you get if you do:

$ ls -d /sys/devices/system/cpu/cpu?/online

?

Quoted 1 line

2) sleep: invalid number '.0026736'

A sufficiently recent coreutils package should have a sleep command that accepts fractional values. Alternatively you may replace it with usleep:

usleep $RANDOM

Quoted 4 lines

For 1) the cpu number is not being appended. if I give a particular cpu in the script then hotplug in/out works fine.
For 2) a constant msleep 10 works.

If you have msleep but not usleep then try:

                msleep $(($RANDOM / 1000))

Quoted 2 lines

Is it OK for me to modify the script to hotplug in/off a randomly chosed core ?

No. They must *all* be hotplugged simultaneously with some random timing.

Hi Nicolas,

[...]

Quoted 6 lines

Quoted 2 lines

1) can't create /sys/devices/system/cpu/cpu//online: nonexistent directory

What do you get if you do:

$ ls -d /sys/devices/system/cpu/cpu?/online

ls: /sys/devices/system/cpu/cpu//online: No such file or directory

Quoted 6 lines · Abhilash Kesavan

Hi Nicolas,

[...]

Quoted 3 lines

Quoted 2 lines

1) can't create /sys/devices/system/cpu/cpu//online: nonexistent directory

Quoted 4 lines

Quoted 3 lines

What do you get if you do:

$ ls -d /sys/devices/system/cpu/cpu?/online

ls: /sys/devices/system/cpu/cpu//online: No such file or directory

Somehow, you or your shell replaced the ? character into a / character. You could try with a * instead.

Nicolas

Hi Nicolas,

Quoted 10 lines · Nicolas Pitre

Quoted 8 lines · Abhilash Kesavan

Hi Nicolas,

[...]

Quoted 5 lines

Quoted 2 lines

1) can't create /sys/devices/system/cpu/cpu//online: nonexistent directory

What do you get if you do:

Quoted 5 lines

Quoted 2 lines

Quoted 1 line

$ ls -d /sys/devices/system/cpu/cpu?/online

ls: /sys/devices/system/cpu/cpu//online: No such file or directory

Somehow, you or your shell replaced the ? character into a / character. You could try with a * instead.

With a different RFS your script runs fine without any change. Will update with results once testing is done.

Hi Nicolas,

Quoted 16 lines · Abhilash Kesavan

Hi Nicolas,

Quoted 13 lines · Nicolas Pitre

Quoted 10 lines · Abhilash Kesavan

Hi Nicolas,

[...]

Quoted 6 lines

Quoted 2 lines

1) can't create /sys/devices/system/cpu/cpu//online: nonexistent directory

What do you get if you do:

$ ls -d /sys/devices/system/cpu/cpu?/online

ls: /sys/devices/system/cpu/cpu//online: No such file or directory

Quoted 4 lines

Quoted 2 lines

Somehow, you or your shell replaced the ? character into a / character. You could try with a * instead.

With a different RFS your script runs fine without any change. Will update with results once testing is done.

The script has been running for a few hours on my 5420 based chromebook. I can see all the cores being hotplugged in/out. A snippet of the prints, that I get on running the test, follows:

Quoted 1 line · Abhilash Kesavan

Hi Nicolas,

[...]

Good, that looks pretty good.

Once you implement full cluster shutdown I can provide you with another script stressing that part.

Quoted 4 lines · Nicolas Pitre

Quoted 1 line · Abhilash Kesavan

Hi Nicolas,

Hi all,

Quoted 4 lines

[...]

Good, that looks pretty good.

Thanks for you guys effort and time.

Applied this whole series.

Quoted 4 lines

Once you implement full cluster shutdown I can provide you with another script stressing that part.

Sounds great.

- Kukjin

Quoted 20 lines · Abhilash Kesavan

Hi Nicolas,

Quoted 16 lines · Abhilash Kesavan

Hi Nicolas,

Quoted 13 lines · Nicolas Pitre

Quoted 10 lines · Abhilash Kesavan

Hi Nicolas,

[...]

Quoted 6 lines

Quoted 2 lines

1) can't create /sys/devices/system/cpu/cpu//online: nonexistent directory

What do you get if you do:

$ ls -d /sys/devices/system/cpu/cpu?/online

ls: /sys/devices/system/cpu/cpu//online: No such file or directory

Quoted 8 lines

Quoted 4 lines

Quoted 2 lines

Somehow, you or your shell replaced the ? character into a / character. You could try with a * instead.

With a different RFS your script runs fine without any change. Will update with results once testing is done.

The script has been running for a few hours on my 5420 based chromebook. I can see all the cores being hotplugged in/out. A snippet of the prints, that I get on running the test, follows:

[...]

Good, that looks pretty good.

Once you implement full cluster shutdown I can provide you with another script stressing that part.

Nicolas

Hi Nicolas,

Quoted 2 lines · Nicolas Pitre

Once you implement full cluster shutdown I can provide you with another script stressing that part.

I am done with the cluster power on/off code and it seems to work fine with bL_switcher. Can you please provide me with your stress script.

Quoted 8 lines · Abhilash Kesavan

Hi Nicolas,

Quoted 2 lines · Nicolas Pitre

Once you implement full cluster shutdown I can provide you with another script stressing that part.

I am done with the cluster power on/off code and it seems to work fine with bL_switcher. Can you please provide me with your stress script.

Here's the script. Credits go to Dave Martin for this one.

The script assumes that cluster 0 comprises cpus 0 to 3 and cluster 1 comprises cpus 4 to 7. You need to edit it otherwise.

----- >8
#!/bin/bash

echo 0 >/sys/kernel/bL_switcher/active
sleep 1

pids=

for x in \
        "cluster=cluster0; cpus='cpu0 cpu1 cpu2 cpu3'" \
        "cluster=cluster1; cpus='cpu4 cpu5 cpu6 cpu7'"
do
        eval "$x"
        eval "\
$cluster () {
        pids=
                `for cpu in $cpus; do cat <<EOF; done
        (sleep .00\\$RANDOM; echo \\$1 >/sys/devices/system/cpu/$cpu/online)&
        echo \\$1 >/sys/devices/system/cpu/$cpu/online&
        pids=\\$pids\ \\$!
EOF`
        wait \$pids
        if [ \$1 = 0 ]; then
                echo \"\$n: $cluster off\"
        else
                echo \"\$n: $cluster on\"
        fi
}"

done

n=0
while :; do
: $((++n))
cluster1 1; cluster0 0
cluster0 1; cluster1 0
done
----- >8