[PATCH] arch: arm64: kernel: add '#ifdef CONFIG_COMPAT' for aarch32_break_handler()

[PATCH] arch: arm64: kernel: add '#ifdef CONFIG_COMPAT' for aarch32_break_handler()

[Chen Gang]

If 'COMPAT' not defined, aarch32_break_handler() cannot pass compiling,
so need add '#ifdef' for it just like the header file has done.

The related make:

  make ARCH=arm64 randconfig
  make ARCH=arm64 menuconfig
  make ARCH=arm64 V=1 EXTRA_CFLAGS=-W

The related error:

  arch/arm64/kernel/debug-monitors.c:249:5: error: redefinition of ?aarch32_break_handler?
  In file included from arch/arm64/kernel/debug-monitors.c:29:0:
  /root/linux-next/arch/arm64/include/asm/debug-monitors.h:89:12: note: previous definition of ?aarch32_break_handler? was here


Signed-off-by: Chen Gang <gang.chen@asianux.com>
---
 arch/arm64/kernel/debug-monitors.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index 08018e3..ceedcd7 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -246,6 +246,7 @@ static int brk_handler(unsigned long addr, unsigned int esr,
 	return 0;
 }
 
+#ifdef CONFIG_COMPAT
 int aarch32_break_handler(struct pt_regs *regs)
 {
 	siginfo_t info;
@@ -285,6 +286,7 @@ int aarch32_break_handler(struct pt_regs *regs)
 	force_sig_info(SIGTRAP, &info, current);
 	return 0;
 }
+#endif
 
 static int __init debug_traps_init(void)
 {
-- 
1.7.7.6

[PATCH] arch: arm64: kernel: add '#ifdef CONFIG_COMPAT' for aarch32_break_handler()

[Will Deacon]

On Sat, Jun 22, 2013 at 06:54:14AM +0100, Chen Gang wrote:
> 
> If 'COMPAT' not defined, aarch32_break_handler() cannot pass compiling,
> so need add '#ifdef' for it just like the header file has done.
> 
> The related make:
> 
>   make ARCH=arm64 randconfig
>   make ARCH=arm64 menuconfig
>   make ARCH=arm64 V=1 EXTRA_CFLAGS=-W
> 
> The related error:
> 
>   arch/arm64/kernel/debug-monitors.c:249:5: error: redefinition of ?aarch32_break_handler?
>   In file included from arch/arm64/kernel/debug-monitors.c:29:0:
>   /root/linux-next/arch/arm64/include/asm/debug-monitors.h:89:12: note: previous definition of ?aarch32_break_handler? was here

Actually, can we just kill the static definition in debug-monitors.h
instead? I don't see anything in the full-blown aardch32_break_handler that
won't play nicely if !COMPAT.

Will

[PATCH] arch: arm64: kernel: add '#ifdef CONFIG_COMPAT' for aarch32_break_handler()

[Chen Gang]

On 06/24/2013 04:47 PM, Will Deacon wrote:
> On Sat, Jun 22, 2013 at 06:54:14AM +0100, Chen Gang wrote:
>> > 
>> > If 'COMPAT' not defined, aarch32_break_handler() cannot pass compiling,
>> > so need add '#ifdef' for it just like the header file has done.
>> > 
>> > The related make:
>> > 
>> >   make ARCH=arm64 randconfig
>> >   make ARCH=arm64 menuconfig
>> >   make ARCH=arm64 V=1 EXTRA_CFLAGS=-W
>> > 
>> > The related error:
>> > 
>> >   arch/arm64/kernel/debug-monitors.c:249:5: error: redefinition of ?aarch32_break_handler?
>> >   In file included from arch/arm64/kernel/debug-monitors.c:29:0:
>> >   /root/linux-next/arch/arm64/include/asm/debug-monitors.h:89:12: note: previous definition of ?aarch32_break_handler? was here
> Actually, can we just kill the static definition in debug-monitors.h
> instead? I don't see anything in the full-blown aardch32_break_handler that
> won't play nicely if !COMPAT.

It sounds good, I will send patch v2.

Thanks.
-- 
Chen Gang

Asianux Corporation

[PATCH v2] arch: arm64: kernel: add '#ifdef CONFIG_COMPAT' for aarch32_break_handler()

[Chen Gang]

If 'COMPAT' not defined, aarch32_break_handler() cannot pass compiling,
and it can work independent with 'COMPAT', so remove dummy definition.

The related make:

  make ARCH=arm64 randconfig
  make ARCH=arm64 menuconfig
  make ARCH=arm64 V=1 EXTRA_CFLAGS=-W

The related error:

  arch/arm64/kernel/debug-monitors.c:249:5: error: redefinition of ?aarch32_break_handler?
  In file included from arch/arm64/kernel/debug-monitors.c:29:0:
  /root/linux-next/arch/arm64/include/asm/debug-monitors.h:89:12: note: previous definition of ?aarch32_break_handler? was here



Signed-off-by: Chen Gang <gang.chen@asianux.com>
---
 arch/arm64/include/asm/debug-monitors.h |    7 -------
 1 files changed, 0 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
index ef8235c..a2232d0 100644
--- a/arch/arm64/include/asm/debug-monitors.h
+++ b/arch/arm64/include/asm/debug-monitors.h
@@ -83,14 +83,7 @@ static inline int reinstall_suspended_bps(struct pt_regs *regs)
 }
 #endif
 
-#ifdef CONFIG_COMPAT
 int aarch32_break_handler(struct pt_regs *regs);
-#else
-static int aarch32_break_handler(struct pt_regs *regs)
-{
-	return -EFAULT;
-}
-#endif
 
 #endif	/* __ASSEMBLY */
 #endif	/* __KERNEL__ */
-- 
1.7.7.6

[PATCH v2] arch: arm64: kernel: add '#ifdef CONFIG_COMPAT' for aarch32_break_handler()

[Will Deacon]

On Mon, Jun 24, 2013 at 10:27:49AM +0100, Chen Gang wrote:
> 
> If 'COMPAT' not defined, aarch32_break_handler() cannot pass compiling,
> and it can work independent with 'COMPAT', so remove dummy definition.
> 
> The related make:
> 
>   make ARCH=arm64 randconfig
>   make ARCH=arm64 menuconfig
>   make ARCH=arm64 V=1 EXTRA_CFLAGS=-W

This sequence isn't really very useful, so I wouldn't bother including it in
the commit message. You can trigger this issue just by disabling
CONFIG_COMPAT.

> The related error:
> 
>   arch/arm64/kernel/debug-monitors.c:249:5: error: redefinition of ?aarch32_break_handler?
>   In file included from arch/arm64/kernel/debug-monitors.c:29:0:
>   /root/linux-next/arch/arm64/include/asm/debug-monitors.h:89:12: note: previous definition of ?aarch32_break_handler? was here
> 
> 
> 
> Signed-off-by: Chen Gang <gang.chen@asianux.com>
> ---
>  arch/arm64/include/asm/debug-monitors.h |    7 -------
>  1 files changed, 0 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
> index ef8235c..a2232d0 100644
> --- a/arch/arm64/include/asm/debug-monitors.h
> +++ b/arch/arm64/include/asm/debug-monitors.h
> @@ -83,14 +83,7 @@ static inline int reinstall_suspended_bps(struct pt_regs *regs)
>  }
>  #endif
>  
> -#ifdef CONFIG_COMPAT
>  int aarch32_break_handler(struct pt_regs *regs);
> -#else
> -static int aarch32_break_handler(struct pt_regs *regs)
> -{
> -	return -EFAULT;
> -}
> -#endif

Code looks fine to me:

  Acked-by: Will Deacon <will.deacon@arm.com>

Will

[PATCH v2] arch: arm64: kernel: add '#ifdef CONFIG_COMPAT' for aarch32_break_handler()

[Chen Gang]

On 06/24/2013 06:14 PM, Will Deacon wrote:
> On Mon, Jun 24, 2013 at 10:27:49AM +0100, Chen Gang wrote:
>> > 
>> > If 'COMPAT' not defined, aarch32_break_handler() cannot pass compiling,
>> > and it can work independent with 'COMPAT', so remove dummy definition.
>> > 
>> > The related make:
>> > 
>> >   make ARCH=arm64 randconfig
>> >   make ARCH=arm64 menuconfig
>> >   make ARCH=arm64 V=1 EXTRA_CFLAGS=-W
> This sequence isn't really very useful, so I wouldn't bother including it in
> the commit message. You can trigger this issue just by disabling
> CONFIG_COMPAT.
> 

OK, thanks. Next time, I need notice about it.

>> > The related error:
>> > 
>> >   arch/arm64/kernel/debug-monitors.c:249:5: error: redefinition of ?aarch32_break_handler?
>> >   In file included from arch/arm64/kernel/debug-monitors.c:29:0:
>> >   /root/linux-next/arch/arm64/include/asm/debug-monitors.h:89:12: note: previous definition of ?aarch32_break_handler? was here
>> > 
>> > 
>> > 
>> > Signed-off-by: Chen Gang <gang.chen@asianux.com>
>> > ---
>> >  arch/arm64/include/asm/debug-monitors.h |    7 -------
>> >  1 files changed, 0 insertions(+), 7 deletions(-)
>> > 
>> > diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
>> > index ef8235c..a2232d0 100644
>> > --- a/arch/arm64/include/asm/debug-monitors.h
>> > +++ b/arch/arm64/include/asm/debug-monitors.h
>> > @@ -83,14 +83,7 @@ static inline int reinstall_suspended_bps(struct pt_regs *regs)
>> >  }
>> >  #endif
>> >  
>> > -#ifdef CONFIG_COMPAT
>> >  int aarch32_break_handler(struct pt_regs *regs);
>> > -#else
>> > -static int aarch32_break_handler(struct pt_regs *regs)
>> > -{
>> > -	return -EFAULT;
>> > -}
>> > -#endif
> Code looks fine to me:
> 
>   Acked-by: Will Deacon <will.deacon@arm.com>

Thanks.

-- 
Chen Gang

Asianux Corporation

[Suggestion] arch: arm64: xen: "ln -s" the paravirt.h from arm.

[Stefano Stabellini]

On Mon, 24 Jun 2013, Chen Gang wrote:
> Hello Maintainers:
> 
> if 'CONFIG_XEN'
> 
>   CC      arch/arm64/xen/../../arm/xen/enlighten.o
> arch/arm64/xen/../../arm/xen/enlighten.c:19:26: fatal error: asm/paravirt.h: No such file or directory
> 
> The related .config file for next-20130624 is in attachment.
> 
> 
> If "ln -s ../../../arm/include/asm/paravirt.h paravirt.h", it can pass
> compiling, but I do not know how to make a patch for it ("ln -s ..."),
> Do we have another more suitable ways for it (or another fixing ways) ?
> 
> Welcome any suggestions or completions.

The problem is caused by:

commit 3a885582a366caf868b0782041c44854ff4c3568
Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Date:   Wed May 29 10:56:34 2013 +0000

    xen/arm: account for stolen ticks

that is in my tree for linux-next (even though I have not received any
replies from the ARM maintainers so I don't know when and if it is going
to go upstream).

I think that the best thing to do would be to add a couple of ifdef
CONFIG_PARAVIRT in arch/arm/xen/enlighten.c. I'll add them to my tree.

[Suggestion] arch: arm64: xen: "ln -s" the paravirt.h from arm.

[Stefano Stabellini]

On Mon, 24 Jun 2013, Stefano Stabellini wrote:
> On Mon, 24 Jun 2013, Chen Gang wrote:
> > Hello Maintainers:
> > 
> > if 'CONFIG_XEN'
> > 
> >   CC      arch/arm64/xen/../../arm/xen/enlighten.o
> > arch/arm64/xen/../../arm/xen/enlighten.c:19:26: fatal error: asm/paravirt.h: No such file or directory
> > 
> > The related .config file for next-20130624 is in attachment.
> > 
> > 
> > If "ln -s ../../../arm/include/asm/paravirt.h paravirt.h", it can pass
> > compiling, but I do not know how to make a patch for it ("ln -s ..."),
> > Do we have another more suitable ways for it (or another fixing ways) ?
> > 
> > Welcome any suggestions or completions.
> 
> The problem is caused by:
> 
> commit 3a885582a366caf868b0782041c44854ff4c3568
> Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> Date:   Wed May 29 10:56:34 2013 +0000
> 
>     xen/arm: account for stolen ticks
> 
> that is in my tree for linux-next (even though I have not received any
> replies from the ARM maintainers so I don't know when and if it is going
> to go upstream).
> 
> I think that the best thing to do would be to add a couple of ifdef
> CONFIG_PARAVIRT in arch/arm/xen/enlighten.c. I'll add them to my tree.

Actually now that we have XEN support under arm64, we can just introduce the
same pv_time_op struct and paravirt header that this patch

http://marc.info/?l=linux-arm-kernel&m=136992435301890&w=2

is introducing under arm.
Any opinions?

---

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 19c1cde..47bd26b 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -207,6 +207,25 @@ config FORCE_MAX_ZONEORDER
 	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
 	default "11"
 
+config PARAVIRT
+	bool "Enable paravirtualization code"
+	---help---
+	  This changes the kernel so it can modify itself when it is run
+	  under a hypervisor, potentially improving performance significantly
+	  over full virtualization.
+
+config PARAVIRT_TIME_ACCOUNTING
+	bool "Paravirtual steal time accounting"
+	select PARAVIRT
+	default n
+	---help---
+	  Select this option to enable fine granularity task steal time
+	  accounting. Time spent executing other tasks in parallel with
+	  the current vCPU is discounted from the vCPU power. To account for
+	  that, there can be a small performance impact.
+
+	  If in doubt, say N here.
+
 config XEN_DOM0
 	def_bool y
 	depends on XEN
@@ -214,6 +233,7 @@ config XEN_DOM0
 config XEN
 	bool "Xen guest support on ARM64 (EXPERIMENTAL)"
 	depends on ARM64 && OF
+	select PARAVIRT
 	help
 	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
 
diff --git a/arch/arm64/include/asm/paravirt.h b/arch/arm64/include/asm/paravirt.h
new file mode 100644
index 0000000..54e895b
--- /dev/null
+++ b/arch/arm64/include/asm/paravirt.h
@@ -0,0 +1,19 @@
+#ifndef _ASM_ARM64_PARAVIRT_H
+#define _ASM_ARM64_PARAVIRT_H
+
+struct static_key;
+extern struct static_key paravirt_steal_enabled;
+extern struct static_key paravirt_steal_rq_enabled;
+
+struct pv_time_ops {
+	unsigned long long (*steal_clock)(int cpu);
+};
+extern struct pv_time_ops pv_time_ops;
+
+static inline u64 paravirt_steal_clock(int cpu)
+{
+	return pv_time_ops.steal_clock(cpu);
+}
+
+
+#endif
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 7b4b564..17613ad 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -18,6 +18,7 @@ arm64-obj-$(CONFIG_SMP)			+= smp.o smp_spin_table.o smp_psci.o
 arm64-obj-$(CONFIG_HW_PERF_EVENTS)	+= perf_event.o
 arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)+= hw_breakpoint.o
 arm64-obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
+arm64-obj-$(CONFIG_PARAVIRT)		+= paravirt.o
 
 obj-y					+= $(arm64-obj-y) vdso/
 obj-m					+= $(arm64-obj-m)
diff --git a/arch/arm64/kernel/paravirt.c b/arch/arm64/kernel/paravirt.c
new file mode 100644
index 0000000..53f371e
--- /dev/null
+++ b/arch/arm64/kernel/paravirt.c
@@ -0,0 +1,25 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Copyright (C) 2013 Citrix Systems
+ *
+ * Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
+ */
+
+#include <linux/export.h>
+#include <linux/jump_label.h>
+#include <linux/types.h>
+#include <asm/paravirt.h>
+
+struct static_key paravirt_steal_enabled;
+struct static_key paravirt_steal_rq_enabled;
+
+struct pv_time_ops pv_time_ops;
+EXPORT_SYMBOL_GPL(pv_time_ops);

[Suggestion] arch: arm64: xen: "ln -s" the paravirt.h from arm.

[Chen Gang]

On 06/25/2013 12:50 AM, Stefano Stabellini wrote:
> On Mon, 24 Jun 2013, Stefano Stabellini wrote:
>> > On Mon, 24 Jun 2013, Chen Gang wrote:
>>> > > Hello Maintainers:
>>> > > 
>>> > > if 'CONFIG_XEN'
>>> > > 
>>> > >   CC      arch/arm64/xen/../../arm/xen/enlighten.o
>>> > > arch/arm64/xen/../../arm/xen/enlighten.c:19:26: fatal error: asm/paravirt.h: No such file or directory
>>> > > 
>>> > > The related .config file for next-20130624 is in attachment.
>>> > > 
>>> > > 
>>> > > If "ln -s ../../../arm/include/asm/paravirt.h paravirt.h", it can pass
>>> > > compiling, but I do not know how to make a patch for it ("ln -s ..."),
>>> > > Do we have another more suitable ways for it (or another fixing ways) ?
>>> > > 
>>> > > Welcome any suggestions or completions.
>> > 
>> > The problem is caused by:
>> > 
>> > commit 3a885582a366caf868b0782041c44854ff4c3568
>> > Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
>> > Date:   Wed May 29 10:56:34 2013 +0000
>> > 
>> >     xen/arm: account for stolen ticks
>> > 
>> > that is in my tree for linux-next (even though I have not received any
>> > replies from the ARM maintainers so I don't know when and if it is going
>> > to go upstream).
>> > 
>> > I think that the best thing to do would be to add a couple of ifdef
>> > CONFIG_PARAVIRT in arch/arm/xen/enlighten.c. I'll add them to my tree.
> Actually now that we have XEN support under arm64, we can just introduce the
> same pv_time_op struct and paravirt header that this patch
> 
> http://marc.info/?l=linux-arm-kernel&m=136992435301890&w=2
> 
> is introducing under arm.
> Any opinions?
> 

OK, thanks, and excuse me, I can not open the link above (the reason
maybe it can not be accessed from China).

But at least, the patch below is better than "ln -s" (which I provided).

Thanks.

> ---
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 19c1cde..47bd26b 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -207,6 +207,25 @@ config FORCE_MAX_ZONEORDER
>  	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
>  	default "11"
>  
> +config PARAVIRT
> +	bool "Enable paravirtualization code"
> +	---help---
> +	  This changes the kernel so it can modify itself when it is run
> +	  under a hypervisor, potentially improving performance significantly
> +	  over full virtualization.
> +
> +config PARAVIRT_TIME_ACCOUNTING
> +	bool "Paravirtual steal time accounting"
> +	select PARAVIRT
> +	default n
> +	---help---
> +	  Select this option to enable fine granularity task steal time
> +	  accounting. Time spent executing other tasks in parallel with
> +	  the current vCPU is discounted from the vCPU power. To account for
> +	  that, there can be a small performance impact.
> +
> +	  If in doubt, say N here.
> +
>  config XEN_DOM0
>  	def_bool y
>  	depends on XEN
> @@ -214,6 +233,7 @@ config XEN_DOM0
>  config XEN
>  	bool "Xen guest support on ARM64 (EXPERIMENTAL)"
>  	depends on ARM64 && OF
> +	select PARAVIRT
>  	help
>  	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
>  
> diff --git a/arch/arm64/include/asm/paravirt.h b/arch/arm64/include/asm/paravirt.h
> new file mode 100644
> index 0000000..54e895b
> --- /dev/null
> +++ b/arch/arm64/include/asm/paravirt.h
> @@ -0,0 +1,19 @@
> +#ifndef _ASM_ARM64_PARAVIRT_H
> +#define _ASM_ARM64_PARAVIRT_H
> +
> +struct static_key;
> +extern struct static_key paravirt_steal_enabled;
> +extern struct static_key paravirt_steal_rq_enabled;
> +
> +struct pv_time_ops {
> +	unsigned long long (*steal_clock)(int cpu);
> +};
> +extern struct pv_time_ops pv_time_ops;
> +
> +static inline u64 paravirt_steal_clock(int cpu)
> +{
> +	return pv_time_ops.steal_clock(cpu);
> +}
> +
> +
> +#endif
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index 7b4b564..17613ad 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -18,6 +18,7 @@ arm64-obj-$(CONFIG_SMP)			+= smp.o smp_spin_table.o smp_psci.o
>  arm64-obj-$(CONFIG_HW_PERF_EVENTS)	+= perf_event.o
>  arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)+= hw_breakpoint.o
>  arm64-obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
> +arm64-obj-$(CONFIG_PARAVIRT)		+= paravirt.o
>  
>  obj-y					+= $(arm64-obj-y) vdso/
>  obj-m					+= $(arm64-obj-m)
> diff --git a/arch/arm64/kernel/paravirt.c b/arch/arm64/kernel/paravirt.c
> new file mode 100644
> index 0000000..53f371e
> --- /dev/null
> +++ b/arch/arm64/kernel/paravirt.c
> @@ -0,0 +1,25 @@
> +/*
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * Copyright (C) 2013 Citrix Systems
> + *
> + * Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> + */
> +
> +#include <linux/export.h>
> +#include <linux/jump_label.h>
> +#include <linux/types.h>
> +#include <asm/paravirt.h>
> +
> +struct static_key paravirt_steal_enabled;
> +struct static_key paravirt_steal_rq_enabled;
> +
> +struct pv_time_ops pv_time_ops;
> +EXPORT_SYMBOL_GPL(pv_time_ops);
> 
> 


-- 
Chen Gang

Asianux Corporation

[Suggestion] arch: arm64: xen: "ln -s" the paravirt.h from arm.

[Stefano Stabellini]

On Tue, 25 Jun 2013, Chen Gang wrote:
> On 06/25/2013 12:50 AM, Stefano Stabellini wrote:
> > On Mon, 24 Jun 2013, Stefano Stabellini wrote:
> >> > On Mon, 24 Jun 2013, Chen Gang wrote:
> >>> > > Hello Maintainers:
> >>> > > 
> >>> > > if 'CONFIG_XEN'
> >>> > > 
> >>> > >   CC      arch/arm64/xen/../../arm/xen/enlighten.o
> >>> > > arch/arm64/xen/../../arm/xen/enlighten.c:19:26: fatal error: asm/paravirt.h: No such file or directory
> >>> > > 
> >>> > > The related .config file for next-20130624 is in attachment.
> >>> > > 
> >>> > > 
> >>> > > If "ln -s ../../../arm/include/asm/paravirt.h paravirt.h", it can pass
> >>> > > compiling, but I do not know how to make a patch for it ("ln -s ..."),
> >>> > > Do we have another more suitable ways for it (or another fixing ways) ?
> >>> > > 
> >>> > > Welcome any suggestions or completions.
> >> > 
> >> > The problem is caused by:
> >> > 
> >> > commit 3a885582a366caf868b0782041c44854ff4c3568
> >> > Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> >> > Date:   Wed May 29 10:56:34 2013 +0000
> >> > 
> >> >     xen/arm: account for stolen ticks
> >> > 
> >> > that is in my tree for linux-next (even though I have not received any
> >> > replies from the ARM maintainers so I don't know when and if it is going
> >> > to go upstream).
> >> > 
> >> > I think that the best thing to do would be to add a couple of ifdef
> >> > CONFIG_PARAVIRT in arch/arm/xen/enlighten.c. I'll add them to my tree.
> > Actually now that we have XEN support under arm64, we can just introduce the
> > same pv_time_op struct and paravirt header that this patch
> > 
> > http://marc.info/?l=linux-arm-kernel&m=136992435301890&w=2
> > 
> > is introducing under arm.
> > Any opinions?
> > 
> 
> OK, thanks, and excuse me, I can not open the link above (the reason
> maybe it can not be accessed from China).

Strange. If you know how to search for a Message-ID, this one is

1369920902-3546-3-git-send-email-stefano.stabellini at eu.citrix.com


> But at least, the patch below is better than "ln -s" (which I provided).

yeah :)

 
> > ---
> > 
> > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > index 19c1cde..47bd26b 100644
> > --- a/arch/arm64/Kconfig
> > +++ b/arch/arm64/Kconfig
> > @@ -207,6 +207,25 @@ config FORCE_MAX_ZONEORDER
> >  	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
> >  	default "11"
> >  
> > +config PARAVIRT
> > +	bool "Enable paravirtualization code"
> > +	---help---
> > +	  This changes the kernel so it can modify itself when it is run
> > +	  under a hypervisor, potentially improving performance significantly
> > +	  over full virtualization.
> > +
> > +config PARAVIRT_TIME_ACCOUNTING
> > +	bool "Paravirtual steal time accounting"
> > +	select PARAVIRT
> > +	default n
> > +	---help---
> > +	  Select this option to enable fine granularity task steal time
> > +	  accounting. Time spent executing other tasks in parallel with
> > +	  the current vCPU is discounted from the vCPU power. To account for
> > +	  that, there can be a small performance impact.
> > +
> > +	  If in doubt, say N here.
> > +
> >  config XEN_DOM0
> >  	def_bool y
> >  	depends on XEN
> > @@ -214,6 +233,7 @@ config XEN_DOM0
> >  config XEN
> >  	bool "Xen guest support on ARM64 (EXPERIMENTAL)"
> >  	depends on ARM64 && OF
> > +	select PARAVIRT
> >  	help
> >  	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
> >  
> > diff --git a/arch/arm64/include/asm/paravirt.h b/arch/arm64/include/asm/paravirt.h
> > new file mode 100644
> > index 0000000..54e895b
> > --- /dev/null
> > +++ b/arch/arm64/include/asm/paravirt.h
> > @@ -0,0 +1,19 @@
> > +#ifndef _ASM_ARM64_PARAVIRT_H
> > +#define _ASM_ARM64_PARAVIRT_H
> > +
> > +struct static_key;
> > +extern struct static_key paravirt_steal_enabled;
> > +extern struct static_key paravirt_steal_rq_enabled;
> > +
> > +struct pv_time_ops {
> > +	unsigned long long (*steal_clock)(int cpu);
> > +};
> > +extern struct pv_time_ops pv_time_ops;
> > +
> > +static inline u64 paravirt_steal_clock(int cpu)
> > +{
> > +	return pv_time_ops.steal_clock(cpu);
> > +}
> > +
> > +
> > +#endif
> > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> > index 7b4b564..17613ad 100644
> > --- a/arch/arm64/kernel/Makefile
> > +++ b/arch/arm64/kernel/Makefile
> > @@ -18,6 +18,7 @@ arm64-obj-$(CONFIG_SMP)			+= smp.o smp_spin_table.o smp_psci.o
> >  arm64-obj-$(CONFIG_HW_PERF_EVENTS)	+= perf_event.o
> >  arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)+= hw_breakpoint.o
> >  arm64-obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
> > +arm64-obj-$(CONFIG_PARAVIRT)		+= paravirt.o
> >  
> >  obj-y					+= $(arm64-obj-y) vdso/
> >  obj-m					+= $(arm64-obj-m)
> > diff --git a/arch/arm64/kernel/paravirt.c b/arch/arm64/kernel/paravirt.c
> > new file mode 100644
> > index 0000000..53f371e
> > --- /dev/null
> > +++ b/arch/arm64/kernel/paravirt.c
> > @@ -0,0 +1,25 @@
> > +/*
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + * GNU General Public License for more details.
> > + *
> > + * Copyright (C) 2013 Citrix Systems
> > + *
> > + * Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> > + */
> > +
> > +#include <linux/export.h>
> > +#include <linux/jump_label.h>
> > +#include <linux/types.h>
> > +#include <asm/paravirt.h>
> > +
> > +struct static_key paravirt_steal_enabled;
> > +struct static_key paravirt_steal_rq_enabled;
> > +
> > +struct pv_time_ops pv_time_ops;
> > +EXPORT_SYMBOL_GPL(pv_time_ops);
> > 
> > 

[Suggestion] arch: arm64: xen: "ln -s" the paravirt.h from arm.

[Catalin Marinas]

On Mon, Jun 24, 2013 at 05:50:46PM +0100, Stefano Stabellini wrote:
> On Mon, 24 Jun 2013, Stefano Stabellini wrote:
> > On Mon, 24 Jun 2013, Chen Gang wrote:
> > > Hello Maintainers:
> > > 
> > > if 'CONFIG_XEN'
> > > 
> > >   CC      arch/arm64/xen/../../arm/xen/enlighten.o
> > > arch/arm64/xen/../../arm/xen/enlighten.c:19:26: fatal error: asm/paravirt.h: No such file or directory
> > > 
> > > The related .config file for next-20130624 is in attachment.
> > > 
> > > 
> > > If "ln -s ../../../arm/include/asm/paravirt.h paravirt.h", it can pass
> > > compiling, but I do not know how to make a patch for it ("ln -s ..."),
> > > Do we have another more suitable ways for it (or another fixing ways) ?
> > > 
> > > Welcome any suggestions or completions.
> > 
> > The problem is caused by:
> > 
> > commit 3a885582a366caf868b0782041c44854ff4c3568
> > Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> > Date:   Wed May 29 10:56:34 2013 +0000
> > 
> >     xen/arm: account for stolen ticks
> > 
> > that is in my tree for linux-next (even though I have not received any
> > replies from the ARM maintainers so I don't know when and if it is going
> > to go upstream).
> > 
> > I think that the best thing to do would be to add a couple of ifdef
> > CONFIG_PARAVIRT in arch/arm/xen/enlighten.c. I'll add them to my tree.
> 
> Actually now that we have XEN support under arm64, we can just introduce the
> same pv_time_op struct and paravirt header that this patch
> 
> http://marc.info/?l=linux-arm-kernel&m=136992435301890&w=2
> 
> is introducing under arm.

I'm not sure whether I replied to your Xen pull request but the patches
have been merged into my 'upstream' branch on git.kernel.org and they'll
be going in for 3.11-rc1.

> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 19c1cde..47bd26b 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -207,6 +207,25 @@ config FORCE_MAX_ZONEORDER
>  	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
>  	default "11"
>  
> +config PARAVIRT
> +	bool "Enable paravirtualization code"
> +	---help---
> +	  This changes the kernel so it can modify itself when it is run
> +	  under a hypervisor, potentially improving performance significantly
> +	  over full virtualization.
> +
> +config PARAVIRT_TIME_ACCOUNTING
> +	bool "Paravirtual steal time accounting"
> +	select PARAVIRT
> +	default n

No need for "default n".

If you want, I can apply this patch on top (or send me another pull
request but don't rebase your original Xen branch which I merged).

-- 
Catalin

[Suggestion] arch: arm64: xen: "ln -s" the paravirt.h from arm.

[Stefano Stabellini]

On Tue, 25 Jun 2013, Catalin Marinas wrote:
> On Mon, Jun 24, 2013 at 05:50:46PM +0100, Stefano Stabellini wrote:
> > On Mon, 24 Jun 2013, Stefano Stabellini wrote:
> > > On Mon, 24 Jun 2013, Chen Gang wrote:
> > > > Hello Maintainers:
> > > > 
> > > > if 'CONFIG_XEN'
> > > > 
> > > >   CC      arch/arm64/xen/../../arm/xen/enlighten.o
> > > > arch/arm64/xen/../../arm/xen/enlighten.c:19:26: fatal error: asm/paravirt.h: No such file or directory
> > > > 
> > > > The related .config file for next-20130624 is in attachment.
> > > > 
> > > > 
> > > > If "ln -s ../../../arm/include/asm/paravirt.h paravirt.h", it can pass
> > > > compiling, but I do not know how to make a patch for it ("ln -s ..."),
> > > > Do we have another more suitable ways for it (or another fixing ways) ?
> > > > 
> > > > Welcome any suggestions or completions.
> > > 
> > > The problem is caused by:
> > > 
> > > commit 3a885582a366caf868b0782041c44854ff4c3568
> > > Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> > > Date:   Wed May 29 10:56:34 2013 +0000
> > > 
> > >     xen/arm: account for stolen ticks
> > > 
> > > that is in my tree for linux-next (even though I have not received any
> > > replies from the ARM maintainers so I don't know when and if it is going
> > > to go upstream).
> > > 
> > > I think that the best thing to do would be to add a couple of ifdef
> > > CONFIG_PARAVIRT in arch/arm/xen/enlighten.c. I'll add them to my tree.
> > 
> > Actually now that we have XEN support under arm64, we can just introduce the
> > same pv_time_op struct and paravirt header that this patch
> > 
> > http://marc.info/?l=linux-arm-kernel&m=136992435301890&w=2
> > 
> > is introducing under arm.
> 
> I'm not sure whether I replied to your Xen pull request but the patches
> have been merged into my 'upstream' branch on git.kernel.org and they'll
> be going in for 3.11-rc1.

Great, thanks!


> > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > index 19c1cde..47bd26b 100644
> > --- a/arch/arm64/Kconfig
> > +++ b/arch/arm64/Kconfig
> > @@ -207,6 +207,25 @@ config FORCE_MAX_ZONEORDER
> >  	default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
> >  	default "11"
> >  
> > +config PARAVIRT
> > +	bool "Enable paravirtualization code"
> > +	---help---
> > +	  This changes the kernel so it can modify itself when it is run
> > +	  under a hypervisor, potentially improving performance significantly
> > +	  over full virtualization.
> > +
> > +config PARAVIRT_TIME_ACCOUNTING
> > +	bool "Paravirtual steal time accounting"
> > +	select PARAVIRT
> > +	default n
> 
> No need for "default n".
> 
> If you want, I can apply this patch on top (or send me another pull
> request but don't rebase your original Xen branch which I merged).

Thanks, but unfortunately the corresponding arm part of this patch
(linked above) didn't manage to get enough reviews and acks.
I might as well send another iteration of "CONFIG_PARAVIRT and stolen
ticks accounting" with this change in it.