[PATCH] don't use flush_tlb_all in suspend time

[PATCH] don't use flush_tlb_all in suspend time

[Shaohua Li]

flush_tlb_all uses on_each_cpu, which will disable/enable interrupt.
In suspend/resume time, this will make interrupt wrongly enabled.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
---

 linux-2.6.17-rc3-root/arch/i386/kernel/acpi/sleep.c   |    2 +-
 linux-2.6.17-rc3-root/arch/i386/mm/init.c             |    5 ++++-
 linux-2.6.17-rc3-root/arch/x86_64/kernel/acpi/sleep.c |    4 ++--
 3 files changed, 7 insertions(+), 4 deletions(-)

diff -puN arch/i386/kernel/acpi/sleep.c~flush_tlb_all_check arch/i386/kernel/acpi/sleep.c
--- linux-2.6.17-rc3/arch/i386/kernel/acpi/sleep.c~flush_tlb_all_check	2006-04-29 08:45:24.000000000 +0800
+++ linux-2.6.17-rc3-root/arch/i386/kernel/acpi/sleep.c	2006-04-29 08:46:49.000000000 +0800
@@ -29,7 +29,7 @@ static void init_low_mapping(pgd_t * pgd
 		set_pgd(pgd, *(pgd + USER_PTRS_PER_PGD));
 		pgd_ofs++, pgd++;
 	}
-	flush_tlb_all();
+	local_flush_tlb();
 }
 
 /**
diff -puN arch/i386/mm/init.c~flush_tlb_all_check arch/i386/mm/init.c
--- linux-2.6.17-rc3/arch/i386/mm/init.c~flush_tlb_all_check	2006-04-29 08:47:05.000000000 +0800
+++ linux-2.6.17-rc3-root/arch/i386/mm/init.c	2006-04-29 08:48:15.000000000 +0800
@@ -420,7 +420,10 @@ void zap_low_mappings (void)
 #else
 		set_pgd(swapper_pg_dir+i, __pgd(0));
 #endif
-	flush_tlb_all();
+	if (cpus_weight(cpu_online_map) == 1)
+		local_flush_tlb();
+	else
+		flush_tlb_all();
 }
 
 static int disable_nx __initdata = 0;
diff -puN arch/x86_64/kernel/acpi/sleep.c~flush_tlb_all_check arch/x86_64/kernel/acpi/sleep.c
--- linux-2.6.17-rc3/arch/x86_64/kernel/acpi/sleep.c~flush_tlb_all_check	2006-04-29 09:16:48.000000000 +0800
+++ linux-2.6.17-rc3-root/arch/x86_64/kernel/acpi/sleep.c	2006-04-29 09:17:19.000000000 +0800
@@ -66,7 +66,7 @@ static void init_low_mapping(void)
 	pgd_t *slot0 = pgd_offset(current->mm, 0UL);
 	low_ptr = *slot0;
 	set_pgd(slot0, *pgd_offset(current->mm, PAGE_OFFSET));
-	flush_tlb_all();
+	local_flush_tlb();
 }
 
 /**
@@ -92,7 +92,7 @@ int acpi_save_state_mem(void)
 void acpi_restore_state_mem(void)
 {
 	set_pgd(pgd_offset(current->mm, 0UL), low_ptr);
-	flush_tlb_all();
+	local_flush_tlb();
 }
 
 /**
_

Re: [PATCH] don't use flush_tlb_all in suspend time

[Pavel Machek]

Hi!

> flush_tlb_all uses on_each_cpu, which will disable/enable interrupt.
> In suspend/resume time, this will make interrupt wrongly enabled.

> diff -puN arch/i386/mm/init.c~flush_tlb_all_check arch/i386/mm/init.c
> --- linux-2.6.17-rc3/arch/i386/mm/init.c~flush_tlb_all_check	2006-04-29 08:47:05.000000000 +0800
> +++ linux-2.6.17-rc3-root/arch/i386/mm/init.c	2006-04-29 08:48:15.000000000 +0800
> @@ -420,7 +420,10 @@ void zap_low_mappings (void)
>  #else
>  		set_pgd(swapper_pg_dir+i, __pgd(0));
>  #endif
> -	flush_tlb_all();
> +	if (cpus_weight(cpu_online_map) == 1)
> +		local_flush_tlb();
> +	else
> +		flush_tlb_all();
>  }
>

Either it is okay to enable interrupts here -> unneccessary and ugly
test, or it is not, and then we are broken in SMP case.

							Pavel
-- 
Thanks, Sharp!

Re: [PATCH] don't use flush_tlb_all in suspend time

[Shaohua Li]

On Sun, 2006-04-30 at 06:45 +0000, Pavel Machek wrote:
> Hi!
> 
> > flush_tlb_all uses on_each_cpu, which will disable/enable interrupt.
> > In suspend/resume time, this will make interrupt wrongly enabled.
> 
> > diff -puN arch/i386/mm/init.c~flush_tlb_all_check arch/i386/mm/init.c
> > --- linux-2.6.17-rc3/arch/i386/mm/init.c~flush_tlb_all_check	2006-04-29 08:47:05.000000000 +0800
> > +++ linux-2.6.17-rc3-root/arch/i386/mm/init.c	2006-04-29 08:48:15.000000000 +0800
> > @@ -420,7 +420,10 @@ void zap_low_mappings (void)
> >  #else
> >  		set_pgd(swapper_pg_dir+i, __pgd(0));
> >  #endif
> > -	flush_tlb_all();
> > +	if (cpus_weight(cpu_online_map) == 1)
> > +		local_flush_tlb();
> > +	else
> > +		flush_tlb_all();
> >  }
> >
> 
> Either it is okay to enable interrupts here -> unneccessary and ugly
> test, or it is not, and then we are broken in SMP case.
It's not broken in SMP case, APs are offlined here in suspend/resume.

Thanks,
Shaohua

Re: [PATCH] don't use flush_tlb_all in suspend time

[Andrew Morton]

Shaohua Li <shaohua.li@intel.com> wrote:
>
> On Sun, 2006-04-30 at 06:45 +0000, Pavel Machek wrote:
> > Hi!
> > 
> > > flush_tlb_all uses on_each_cpu, which will disable/enable interrupt.
> > > In suspend/resume time, this will make interrupt wrongly enabled.
> > 
> > > diff -puN arch/i386/mm/init.c~flush_tlb_all_check arch/i386/mm/init.c
> > > --- linux-2.6.17-rc3/arch/i386/mm/init.c~flush_tlb_all_check	2006-04-29 08:47:05.000000000 +0800
> > > +++ linux-2.6.17-rc3-root/arch/i386/mm/init.c	2006-04-29 08:48:15.000000000 +0800
> > > @@ -420,7 +420,10 @@ void zap_low_mappings (void)
> > >  #else
> > >  		set_pgd(swapper_pg_dir+i, __pgd(0));
> > >  #endif
> > > -	flush_tlb_all();
> > > +	if (cpus_weight(cpu_online_map) == 1)
> > > +		local_flush_tlb();
> > > +	else
> > > +		flush_tlb_all();
> > >  }
> > >
> > 
> > Either it is okay to enable interrupts here -> unneccessary and ugly
> > test, or it is not, and then we are broken in SMP case.
> It's not broken in SMP case, APs are offlined here in suspend/resume.
> 

In which case, how's about this?


 arch/i386/kernel/acpi/sleep.c   |    3 +++
 arch/i386/mm/init.c             |   10 +++++++++-
 arch/x86_64/kernel/acpi/sleep.c |    3 +++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff -puN arch/i386/kernel/acpi/sleep.c~dont-use-flush_tlb_all-in-suspend-time-tidy arch/i386/kernel/acpi/sleep.c
--- devel/arch/i386/kernel/acpi/sleep.c~dont-use-flush_tlb_all-in-suspend-time-tidy	2006-04-29 23:53:33.000000000 -0700
+++ devel-akpm/arch/i386/kernel/acpi/sleep.c	2006-04-29 23:54:09.000000000 -0700
@@ -8,6 +8,8 @@
 #include <linux/acpi.h>
 #include <linux/bootmem.h>
 #include <linux/dmi.h>
+#include <linux/cpumask.h>
+
 #include <asm/smp.h>
 #include <asm/tlbflush.h>
 
@@ -29,6 +31,7 @@ static void init_low_mapping(pgd_t * pgd
 		set_pgd(pgd, *(pgd + USER_PTRS_PER_PGD));
 		pgd_ofs++, pgd++;
 	}
+	WARN_ON(num_online_cpus() != 1);
 	local_flush_tlb();
 }
 
diff -puN arch/i386/mm/init.c~dont-use-flush_tlb_all-in-suspend-time-tidy arch/i386/mm/init.c
--- devel/arch/i386/mm/init.c~dont-use-flush_tlb_all-in-suspend-time-tidy	2006-04-29 23:53:33.000000000 -0700
+++ devel-akpm/arch/i386/mm/init.c	2006-04-29 23:56:00.000000000 -0700
@@ -29,6 +29,7 @@
 #include <linux/efi.h>
 #include <linux/memory_hotplug.h>
 #include <linux/initrd.h>
+#include <linux/cpumask.h>
 
 #include <asm/processor.h>
 #include <asm/system.h>
@@ -420,7 +421,14 @@ void zap_low_mappings (void)
 #else
 		set_pgd(swapper_pg_dir+i, __pgd(0));
 #endif
-	if (cpus_weight(cpu_online_map) == 1)
+	/*
+	 * We can be called at suspend/resume time, with local interrupts
+	 * disabled.  But flush_tlb_all() requires that local interrupts be
+	 * enabled.
+	 *
+	 * Happily, the APs are not yet started, so we can use local_flush_tlb()	 * in that case
+	 */
+	if (num_online_cpus() == 1)
 		local_flush_tlb();
 	else
 		flush_tlb_all();
diff -puN arch/x86_64/kernel/acpi/sleep.c~dont-use-flush_tlb_all-in-suspend-time-tidy arch/x86_64/kernel/acpi/sleep.c
--- devel/arch/x86_64/kernel/acpi/sleep.c~dont-use-flush_tlb_all-in-suspend-time-tidy	2006-04-29 23:53:33.000000000 -0700
+++ devel-akpm/arch/x86_64/kernel/acpi/sleep.c	2006-04-29 23:56:24.000000000 -0700
@@ -35,6 +35,8 @@
 #include <linux/pci.h>
 #include <linux/bootmem.h>
 #include <linux/acpi.h>
+#include <linux/cpumask.h>
+
 #include <asm/mpspec.h>
 #include <asm/io.h>
 #include <asm/apic.h>
@@ -66,6 +68,7 @@ static void init_low_mapping(void)
 	pgd_t *slot0 = pgd_offset(current->mm, 0UL);
 	low_ptr = *slot0;
 	set_pgd(slot0, *pgd_offset(current->mm, PAGE_OFFSET));
+	WARN_ON(num_online_cpus() != 1);
 	local_flush_tlb();
 }
 
_

Re: [PATCH] don't use flush_tlb_all in suspend time

[Shaohua Li]

On Sat, 2006-04-29 at 23:57 -0700, Andrew Morton wrote:
> Shaohua Li <shaohua.li@intel.com> wrote:
> >
> > On Sun, 2006-04-30 at 06:45 +0000, Pavel Machek wrote:
> > > Hi!
> > > 
> > > > flush_tlb_all uses on_each_cpu, which will disable/enable interrupt.
> > > > In suspend/resume time, this will make interrupt wrongly enabled.
> > > 
> > > > diff -puN arch/i386/mm/init.c~flush_tlb_all_check arch/i386/mm/init.c
> > > > --- linux-2.6.17-rc3/arch/i386/mm/init.c~flush_tlb_all_check	2006-04-29 08:47:05.000000000 +0800
> > > > +++ linux-2.6.17-rc3-root/arch/i386/mm/init.c	2006-04-29 08:48:15.000000000 +0800
> > > > @@ -420,7 +420,10 @@ void zap_low_mappings (void)
> > > >  #else
> > > >  		set_pgd(swapper_pg_dir+i, __pgd(0));
> > > >  #endif
> > > > -	flush_tlb_all();
> > > > +	if (cpus_weight(cpu_online_map) == 1)
> > > > +		local_flush_tlb();
> > > > +	else
> > > > +		flush_tlb_all();
> > > >  }
> > > >
> > > 
> > > Either it is okay to enable interrupts here -> unneccessary and ugly
> > > test, or it is not, and then we are broken in SMP case.
> > It's not broken in SMP case, APs are offlined here in suspend/resume.
> > 
> 
> In which case, how's about this?
Yes, this is great. Thanks!


>  arch/i386/kernel/acpi/sleep.c   |    3 +++
>  arch/i386/mm/init.c             |   10 +++++++++-
>  arch/x86_64/kernel/acpi/sleep.c |    3 +++
>  3 files changed, 15 insertions(+), 1 deletion(-)
> 
> diff -puN arch/i386/kernel/acpi/sleep.c~dont-use-flush_tlb_all-in-suspend-time-tidy arch/i386/kernel/acpi/sleep.c
> --- devel/arch/i386/kernel/acpi/sleep.c~dont-use-flush_tlb_all-in-suspend-time-tidy	2006-04-29 23:53:33.000000000 -0700
> +++ devel-akpm/arch/i386/kernel/acpi/sleep.c	2006-04-29 23:54:09.000000000 -0700
> @@ -8,6 +8,8 @@
>  #include <linux/acpi.h>
>  #include <linux/bootmem.h>
>  #include <linux/dmi.h>
> +#include <linux/cpumask.h>
> +
>  #include <asm/smp.h>
>  #include <asm/tlbflush.h>
>  
> @@ -29,6 +31,7 @@ static void init_low_mapping(pgd_t * pgd
>  		set_pgd(pgd, *(pgd + USER_PTRS_PER_PGD));
>  		pgd_ofs++, pgd++;
>  	}
> +	WARN_ON(num_online_cpus() != 1);
>  	local_flush_tlb();
>  }
>  
> diff -puN arch/i386/mm/init.c~dont-use-flush_tlb_all-in-suspend-time-tidy arch/i386/mm/init.c
> --- devel/arch/i386/mm/init.c~dont-use-flush_tlb_all-in-suspend-time-tidy	2006-04-29 23:53:33.000000000 -0700
> +++ devel-akpm/arch/i386/mm/init.c	2006-04-29 23:56:00.000000000 -0700
> @@ -29,6 +29,7 @@
>  #include <linux/efi.h>
>  #include <linux/memory_hotplug.h>
>  #include <linux/initrd.h>
> +#include <linux/cpumask.h>
>  
>  #include <asm/processor.h>
>  #include <asm/system.h>
> @@ -420,7 +421,14 @@ void zap_low_mappings (void)
>  #else
>  		set_pgd(swapper_pg_dir+i, __pgd(0));
>  #endif
> -	if (cpus_weight(cpu_online_map) == 1)
> +	/*
> +	 * We can be called at suspend/resume time, with local interrupts
> +	 * disabled.  But flush_tlb_all() requires that local interrupts be
> +	 * enabled.
> +	 *
> +	 * Happily, the APs are not yet started, so we can use local_flush_tlb()	 * in that case
> +	 */
> +	if (num_online_cpus() == 1)
>  		local_flush_tlb();
>  	else
>  		flush_tlb_all();
> diff -puN arch/x86_64/kernel/acpi/sleep.c~dont-use-flush_tlb_all-in-suspend-time-tidy arch/x86_64/kernel/acpi/sleep.c
> --- devel/arch/x86_64/kernel/acpi/sleep.c~dont-use-flush_tlb_all-in-suspend-time-tidy	2006-04-29 23:53:33.000000000 -0700
> +++ devel-akpm/arch/x86_64/kernel/acpi/sleep.c	2006-04-29 23:56:24.000000000 -0700
> @@ -35,6 +35,8 @@
>  #include <linux/pci.h>
>  #include <linux/bootmem.h>
>  #include <linux/acpi.h>
> +#include <linux/cpumask.h>
> +
>  #include <asm/mpspec.h>
>  #include <asm/io.h>
>  #include <asm/apic.h>
> @@ -66,6 +68,7 @@ static void init_low_mapping(void)
>  	pgd_t *slot0 = pgd_offset(current->mm, 0UL);
>  	low_ptr = *slot0;
>  	set_pgd(slot0, *pgd_offset(current->mm, PAGE_OFFSET));
> +	WARN_ON(num_online_cpus() != 1);
>  	local_flush_tlb();
>  }
>  
> _
-- 
Shaohua Li <shaohua.li@intel.com>

Re: [PATCH] don't use flush_tlb_all in suspend time

[Pavel Machek]

On So 29-04-06 23:57:21, Andrew Morton wrote:
> Shaohua Li <shaohua.li@intel.com> wrote:
> >
> > On Sun, 2006-04-30 at 06:45 +0000, Pavel Machek wrote:
> > > Hi!
> > > 
> > > > flush_tlb_all uses on_each_cpu, which will disable/enable interrupt.
> > > > In suspend/resume time, this will make interrupt wrongly enabled.
> > > 
> > > > diff -puN arch/i386/mm/init.c~flush_tlb_all_check arch/i386/mm/init.c
> > > > --- linux-2.6.17-rc3/arch/i386/mm/init.c~flush_tlb_all_check	2006-04-29 08:47:05.000000000 +0800
> > > > +++ linux-2.6.17-rc3-root/arch/i386/mm/init.c	2006-04-29 08:48:15.000000000 +0800
> > > > @@ -420,7 +420,10 @@ void zap_low_mappings (void)
> > > >  #else
> > > >  		set_pgd(swapper_pg_dir+i, __pgd(0));
> > > >  #endif
> > > > -	flush_tlb_all();
> > > > +	if (cpus_weight(cpu_online_map) == 1)
> > > > +		local_flush_tlb();
> > > > +	else
> > > > +		flush_tlb_all();
> > > >  }
> > > >
> > > 
> > > Either it is okay to enable interrupts here -> unneccessary and ugly
> > > test, or it is not, and then we are broken in SMP case.
> > It's not broken in SMP case, APs are offlined here in suspend/resume.
> > 
> 
> In which case, how's about this?

Certainly better, I'd say.

> @@ -420,7 +421,14 @@ void zap_low_mappings (void)
>  #else
>  		set_pgd(swapper_pg_dir+i, __pgd(0));
>  #endif
> -	if (cpus_weight(cpu_online_map) == 1)
> +	/*
> +	 * We can be called at suspend/resume time, with local interrupts
> +	 * disabled.  But flush_tlb_all() requires that local interrupts be
> +	 * enabled.
> +	 *
> +	 * Happily, the APs are not yet started, so we can use local_flush_tlb()	 * in that case
> +	 */
> +	if (num_online_cpus() == 1)
>  		local_flush_tlb();
>  	else
>  		flush_tlb_all();

But this still scares. It means calling convention is "may enable
interrupts with >1 cpu, may not with == 1 cpu". 

								Pavel
-- 
Thanks for all the (sleeping) penguins.

Re: [PATCH] don't use flush_tlb_all in suspend time

[Shaohua Li]

On Sun, 2006-04-30 at 14:04 +0200, Pavel Machek wrote:
> On So 29-04-06 23:57:21, Andrew Morton wrote:
> > Shaohua Li <shaohua.li@intel.com> wrote:
> > >
> > > On Sun, 2006-04-30 at 06:45 +0000, Pavel Machek wrote:
> > > > Hi!
> > > > 
> > > > > flush_tlb_all uses on_each_cpu, which will disable/enable interrupt.
> > > > > In suspend/resume time, this will make interrupt wrongly enabled.
> > > > 
> > > > > diff -puN arch/i386/mm/init.c~flush_tlb_all_check arch/i386/mm/init.c
> > > > > --- linux-2.6.17-rc3/arch/i386/mm/init.c~flush_tlb_all_check	2006-04-29 08:47:05.000000000 +0800
> > > > > +++ linux-2.6.17-rc3-root/arch/i386/mm/init.c	2006-04-29 08:48:15.000000000 +0800
> > > > > @@ -420,7 +420,10 @@ void zap_low_mappings (void)
> > > > >  #else
> > > > >  		set_pgd(swapper_pg_dir+i, __pgd(0));
> > > > >  #endif
> > > > > -	flush_tlb_all();
> > > > > +	if (cpus_weight(cpu_online_map) == 1)
> > > > > +		local_flush_tlb();
> > > > > +	else
> > > > > +		flush_tlb_all();
> > > > >  }
> > > > >
> > > > 
> > > > Either it is okay to enable interrupts here -> unneccessary and ugly
> > > > test, or it is not, and then we are broken in SMP case.
> > > It's not broken in SMP case, APs are offlined here in suspend/resume.
> > > 
> > 
> > In which case, how's about this?
> 
> Certainly better, I'd say.
> 
> > @@ -420,7 +421,14 @@ void zap_low_mappings (void)
> >  #else
> >  		set_pgd(swapper_pg_dir+i, __pgd(0));
> >  #endif
> > -	if (cpus_weight(cpu_online_map) == 1)
> > +	/*
> > +	 * We can be called at suspend/resume time, with local interrupts
> > +	 * disabled.  But flush_tlb_all() requires that local interrupts be
> > +	 * enabled.
> > +	 *
> > +	 * Happily, the APs are not yet started, so we can use local_flush_tlb()	 * in that case
> > +	 */
> > +	if (num_online_cpus() == 1)
> >  		local_flush_tlb();
> >  	else
> >  		flush_tlb_all();
Sorry for the delay. Last week is holiday here.

> But this still scares. It means calling convention is "may enable
> interrupts with >1 cpu, may not with == 1 cpu". 
Then we need port x86_64's implementation. I'll try if I can work it
out.

Thanks,
Shaohua

Re: [PATCH] don't use flush_tlb_all in suspend time

[Shaohua Li]

On Sun, 2006-04-30 at 14:04 +0200, Pavel Machek wrote:
> On So 29-04-06 23:57:21, Andrew Morton wrote:
> > Shaohua Li <shaohua.li@intel.com> wrote:
> > >
> > > On Sun, 2006-04-30 at 06:45 +0000, Pavel Machek wrote:
> > > > Hi!
> > > > 
> > > > > flush_tlb_all uses on_each_cpu, which will disable/enable interrupt.
> > > > > In suspend/resume time, this will make interrupt wrongly enabled.
> > > > 
> > > > > diff -puN arch/i386/mm/init.c~flush_tlb_all_check arch/i386/mm/init.c
> > > > > --- linux-2.6.17-rc3/arch/i386/mm/init.c~flush_tlb_all_check	2006-04-29 08:47:05.000000000 +0800
> > > > > +++ linux-2.6.17-rc3-root/arch/i386/mm/init.c	2006-04-29 08:48:15.000000000 +0800
> > > > > @@ -420,7 +420,10 @@ void zap_low_mappings (void)
> > > > >  #else
> > > > >  		set_pgd(swapper_pg_dir+i, __pgd(0));
> > > > >  #endif
> > > > > -	flush_tlb_all();
> > > > > +	if (cpus_weight(cpu_online_map) == 1)
> > > > > +		local_flush_tlb();
> > > > > +	else
> > > > > +		flush_tlb_all();
> > > > >  }
> > > > >
> > > > 
> > > > Either it is okay to enable interrupts here -> unneccessary and ugly
> > > > test, or it is not, and then we are broken in SMP case.
> > > It's not broken in SMP case, APs are offlined here in suspend/resume.
> > > 
> > 
> > In which case, how's about this?
> 
> Certainly better, I'd say.
> 
> > @@ -420,7 +421,14 @@ void zap_low_mappings (void)
> >  #else
> >  		set_pgd(swapper_pg_dir+i, __pgd(0));
> >  #endif
> > -	if (cpus_weight(cpu_online_map) == 1)
> > +	/*
> > +	 * We can be called at suspend/resume time, with local interrupts
> > +	 * disabled.  But flush_tlb_all() requires that local interrupts be
> > +	 * enabled.
> > +	 *
> > +	 * Happily, the APs are not yet started, so we can use local_flush_tlb()	 * in that case
> > +	 */
> > +	if (num_online_cpus() == 1)
> >  		local_flush_tlb();
> >  	else
> >  		flush_tlb_all();
> 
> But this still scares. It means calling convention is "may enable
> interrupts with >1 cpu, may not with == 1 cpu". 
Below patch should make things clean. How do you think?

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
---

 linux-2.6.17-rc4-mm1-root/arch/i386/kernel/acpi/sleep.c  |   10 +++-------
 linux-2.6.17-rc4-mm1-root/arch/i386/kernel/acpi/wakeup.S |    2 +-
 linux-2.6.17-rc4-mm1-root/arch/i386/mm/init.c            |   13 +------------
 3 files changed, 5 insertions(+), 20 deletions(-)

diff -puN arch/i386/kernel/acpi/wakeup.S~i386_direct_mapping arch/i386/kernel/acpi/wakeup.S
--- linux-2.6.17-rc4-mm1/arch/i386/kernel/acpi/wakeup.S~i386_direct_mapping	2006-05-16 14:52:37.000000000 +0800
+++ linux-2.6.17-rc4-mm1-root/arch/i386/kernel/acpi/wakeup.S	2006-05-16 15:10:57.000000000 +0800
@@ -56,7 +56,7 @@ wakeup_code:
 1:
 
 	# set up page table
-	movl	$swapper_pg_dir-__PAGE_OFFSET, %eax
+	movl	$sleep_pg_dir-__PAGE_OFFSET, %eax
 	movl	%eax, %cr3
 
 	testl	$1, real_efer_save_restore - wakeup_code
diff -puN arch/i386/kernel/acpi/sleep.c~i386_direct_mapping arch/i386/kernel/acpi/sleep.c
--- linux-2.6.17-rc4-mm1/arch/i386/kernel/acpi/sleep.c~i386_direct_mapping	2006-05-16 14:52:51.000000000 +0800
+++ linux-2.6.17-rc4-mm1-root/arch/i386/kernel/acpi/sleep.c	2006-05-17 09:30:26.000000000 +0800
@@ -11,16 +11,14 @@
 #include <linux/cpumask.h>
 
 #include <asm/smp.h>
-#include <asm/tlbflush.h>
 
 /* address in low memory of the wakeup routine. */
 unsigned long acpi_wakeup_address = 0;
 unsigned long acpi_video_flags;
 extern char wakeup_start, wakeup_end;
 
-extern void zap_low_mappings(void);
-
 extern unsigned long FASTCALL(acpi_copy_wakeup_routine(unsigned long));
+char sleep_pg_dir[PAGE_SIZE];
 
 static void init_low_mapping(pgd_t * pgd, int pgd_limit)
 {
@@ -31,8 +29,6 @@ static void init_low_mapping(pgd_t * pgd
 		set_pgd(pgd, *(pgd + USER_PTRS_PER_PGD));
 		pgd_ofs++, pgd++;
 	}
-	WARN_ON(num_online_cpus() != 1);
-	local_flush_tlb();
 }
 
 /**
@@ -45,7 +41,8 @@ int acpi_save_state_mem(void)
 {
 	if (!acpi_wakeup_address)
 		return 1;
-	init_low_mapping(swapper_pg_dir, USER_PTRS_PER_PGD);
+	memcpy(sleep_pg_dir, swapper_pg_dir, PAGE_SIZE);
+	init_low_mapping((pgd_t *)sleep_pg_dir, USER_PTRS_PER_PGD);
 	memcpy((void *)acpi_wakeup_address, &wakeup_start,
 	       &wakeup_end - &wakeup_start);
 	acpi_copy_wakeup_routine(acpi_wakeup_address);
@@ -58,7 +55,6 @@ int acpi_save_state_mem(void)
  */
 void acpi_restore_state_mem(void)
 {
-	zap_low_mappings();
 }
 
 /**
diff -puN arch/i386/mm/init.c~i386_direct_mapping arch/i386/mm/init.c
--- linux-2.6.17-rc4-mm1/arch/i386/mm/init.c~i386_direct_mapping	2006-05-17 09:03:39.000000000 +0800
+++ linux-2.6.17-rc4-mm1-root/arch/i386/mm/init.c	2006-05-17 09:03:49.000000000 +0800
@@ -422,18 +422,7 @@ void zap_low_mappings (void)
 #else
 		set_pgd(swapper_pg_dir+i, __pgd(0));
 #endif
-	/*
-	 * We can be called at suspend/resume time, with local interrupts
-	 * disabled.  But flush_tlb_all() requires that local interrupts be
-	 * enabled.
-	 *
-	 * Happily, the APs are not yet started, so we can use local_flush_tlb()
-	 * in that case
-	 */
-	if (num_online_cpus() == 1)
-		local_flush_tlb();
-	else
-		flush_tlb_all();
+	flush_tlb_all();
 }
 
 static int disable_nx __initdata = 0;
_

Re: [PATCH] don't use flush_tlb_all in suspend time

[Pavel Machek]

Hi!

> > > In which case, how's about this?
> > 
> > Certainly better, I'd say.
> > 
> > > @@ -420,7 +421,14 @@ void zap_low_mappings (void)
> > >  #else
> > >  		set_pgd(swapper_pg_dir+i, __pgd(0));
> > >  #endif
> > > -	if (cpus_weight(cpu_online_map) == 1)
> > > +	/*
> > > +	 * We can be called at suspend/resume time, with local interrupts
> > > +	 * disabled.  But flush_tlb_all() requires that local interrupts be
> > > +	 * enabled.
> > > +	 *
> > > +	 * Happily, the APs are not yet started, so we can use local_flush_tlb()	 * in that case
> > > +	 */
> > > +	if (num_online_cpus() == 1)
> > >  		local_flush_tlb();
> > >  	else
> > >  		flush_tlb_all();
> > 
> > But this still scares. It means calling convention is "may enable
> > interrupts with >1 cpu, may not with == 1 cpu". 
> Below patch should make things clean. How do you think?

Nice...

Could we perhaps reuse swsusp_pg_dir (just make it used for swsusp &
suspend-to-ram) to save a bit more code? It is in arch/i386/mm/init.c
.

								Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [PATCH] don't use flush_tlb_all in suspend time

[Shaohua Li]

On Thu, 2006-05-18 at 10:31 +0200, Pavel Machek wrote:
> Hi!
> 
> > > > In which case, how's about this?
> > > 
> > > Certainly better, I'd say.
> > > 
> > > > @@ -420,7 +421,14 @@ void zap_low_mappings (void)
> > > >  #else
> > > >  		set_pgd(swapper_pg_dir+i, __pgd(0));
> > > >  #endif
> > > > -	if (cpus_weight(cpu_online_map) == 1)
> > > > +	/*
> > > > +	 * We can be called at suspend/resume time, with local interrupts
> > > > +	 * disabled.  But flush_tlb_all() requires that local interrupts be
> > > > +	 * enabled.
> > > > +	 *
> > > > +	 * Happily, the APs are not yet started, so we can use local_flush_tlb()	 * in that case
> > > > +	 */
> > > > +	if (num_online_cpus() == 1)
> > > >  		local_flush_tlb();
> > > >  	else
> > > >  		flush_tlb_all();
> > > 
> > > But this still scares. It means calling convention is "may enable
> > > interrupts with >1 cpu, may not with == 1 cpu". 
> > Below patch should make things clean. How do you think?
> 
> Nice...
> 
> Could we perhaps reuse swsusp_pg_dir (just make it used for swsusp &
> suspend-to-ram) to save a bit more code? It is in arch/i386/mm/init.c
Sure. But it's under CONFIG_SOFTWARE_SUSPEND. That part needs cleanup I
think and it's a little strange to me (why should we simply copy
swapper_pg_dir to swsusp_pg_dir, instead do it in zap_low_mappings?).

Thanks,
Shaohua

Re: [PATCH] don't use flush_tlb_all in suspend time

[Pavel Machek]

On Čt 18-05-06 16:38:21, Shaohua Li wrote:
> On Thu, 2006-05-18 at 10:31 +0200, Pavel Machek wrote:
> > Hi!
> > 
> > > > > In which case, how's about this?
> > > > 
> > > > Certainly better, I'd say.
> > > > 
> > > > > @@ -420,7 +421,14 @@ void zap_low_mappings (void)
> > > > >  #else
> > > > >  		set_pgd(swapper_pg_dir+i, __pgd(0));
> > > > >  #endif
> > > > > -	if (cpus_weight(cpu_online_map) == 1)
> > > > > +	/*
> > > > > +	 * We can be called at suspend/resume time, with local interrupts
> > > > > +	 * disabled.  But flush_tlb_all() requires that local interrupts be
> > > > > +	 * enabled.
> > > > > +	 *
> > > > > +	 * Happily, the APs are not yet started, so we can use local_flush_tlb()	 * in that case
> > > > > +	 */
> > > > > +	if (num_online_cpus() == 1)
> > > > >  		local_flush_tlb();
> > > > >  	else
> > > > >  		flush_tlb_all();
> > > > 
> > > > But this still scares. It means calling convention is "may enable
> > > > interrupts with >1 cpu, may not with == 1 cpu". 
> > > Below patch should make things clean. How do you think?
> > 
> > Nice...
> > 
> > Could we perhaps reuse swsusp_pg_dir (just make it used for swsusp &
> > suspend-to-ram) to save a bit more code? It is in arch/i386/mm/init.c
> Sure. But it's under CONFIG_SOFTWARE_SUSPEND. 

Yes, #ifdef definitely does need to change there.

> That part needs cleanup I
> think and it's a little strange to me (why should we simply copy
> swapper_pg_dir to swsusp_pg_dir, instead do it in zap_low_mappings?).

?? Sorry, I do not understand. "instead of doing"?
								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [PATCH] don't use flush_tlb_all in suspend time

[Shaohua Li]

On Thu, 2006-05-18 at 10:31 +0200, Pavel Machek wrote:
> Hi!
> 
> > > > In which case, how's about this?
> > > 
> > > Certainly better, I'd say.
> > > 
> > > > @@ -420,7 +421,14 @@ void zap_low_mappings (void)
> > > >  #else
> > > >  		set_pgd(swapper_pg_dir+i, __pgd(0));
> > > >  #endif
> > > > -	if (cpus_weight(cpu_online_map) == 1)
> > > > +	/*
> > > > +	 * We can be called at suspend/resume time, with local interrupts
> > > > +	 * disabled.  But flush_tlb_all() requires that local interrupts be
> > > > +	 * enabled.
> > > > +	 *
> > > > +	 * Happily, the APs are not yet started, so we can use local_flush_tlb()	 * in that case
> > > > +	 */
> > > > +	if (num_online_cpus() == 1)
> > > >  		local_flush_tlb();
> > > >  	else
> > > >  		flush_tlb_all();
> > > 
> > > But this still scares. It means calling convention is "may enable
> > > interrupts with >1 cpu, may not with == 1 cpu". 
> > Below patch should make things clean. How do you think?
> 
> Nice...
> 
> Could we perhaps reuse swsusp_pg_dir (just make it used for swsusp &
> suspend-to-ram) to save a bit more code? It is in arch/i386/mm/init.c
Ok, I guess this is what you want.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
---

 linux-2.6.17-rc4-mm1-root/arch/i386/kernel/acpi/sleep.c  |   18 ---------------
 linux-2.6.17-rc4-mm1-root/arch/i386/kernel/acpi/wakeup.S |    2 -
 linux-2.6.17-rc4-mm1-root/arch/i386/mm/init.c            |   15 +-----------
 3 files changed, 3 insertions(+), 32 deletions(-)

diff -puN arch/i386/kernel/acpi/wakeup.S~i386_direct_mapping arch/i386/kernel/acpi/wakeup.S
--- linux-2.6.17-rc4-mm1/arch/i386/kernel/acpi/wakeup.S~i386_direct_mapping	2006-05-16 14:52:37.000000000 +0800
+++ linux-2.6.17-rc4-mm1-root/arch/i386/kernel/acpi/wakeup.S	2006-05-18 07:12:40.000000000 +0800
@@ -56,7 +56,7 @@ wakeup_code:
 1:
 
 	# set up page table
-	movl	$swapper_pg_dir-__PAGE_OFFSET, %eax
+	movl	$swsusp_pg_dir-__PAGE_OFFSET, %eax
 	movl	%eax, %cr3
 
 	testl	$1, real_efer_save_restore - wakeup_code
diff -puN arch/i386/kernel/acpi/sleep.c~i386_direct_mapping arch/i386/kernel/acpi/sleep.c
--- linux-2.6.17-rc4-mm1/arch/i386/kernel/acpi/sleep.c~i386_direct_mapping	2006-05-16 14:52:51.000000000 +0800
+++ linux-2.6.17-rc4-mm1-root/arch/i386/kernel/acpi/sleep.c	2006-05-18 07:11:38.000000000 +0800
@@ -11,30 +11,14 @@
 #include <linux/cpumask.h>
 
 #include <asm/smp.h>
-#include <asm/tlbflush.h>
 
 /* address in low memory of the wakeup routine. */
 unsigned long acpi_wakeup_address = 0;
 unsigned long acpi_video_flags;
 extern char wakeup_start, wakeup_end;
 
-extern void zap_low_mappings(void);
-
 extern unsigned long FASTCALL(acpi_copy_wakeup_routine(unsigned long));
 
-static void init_low_mapping(pgd_t * pgd, int pgd_limit)
-{
-	int pgd_ofs = 0;
-
-	while ((pgd_ofs < pgd_limit)
-	       && (pgd_ofs + USER_PTRS_PER_PGD < PTRS_PER_PGD)) {
-		set_pgd(pgd, *(pgd + USER_PTRS_PER_PGD));
-		pgd_ofs++, pgd++;
-	}
-	WARN_ON(num_online_cpus() != 1);
-	local_flush_tlb();
-}
-
 /**
  * acpi_save_state_mem - save kernel state
  *
@@ -45,7 +29,6 @@ int acpi_save_state_mem(void)
 {
 	if (!acpi_wakeup_address)
 		return 1;
-	init_low_mapping(swapper_pg_dir, USER_PTRS_PER_PGD);
 	memcpy((void *)acpi_wakeup_address, &wakeup_start,
 	       &wakeup_end - &wakeup_start);
 	acpi_copy_wakeup_routine(acpi_wakeup_address);
@@ -58,7 +41,6 @@ int acpi_save_state_mem(void)
  */
 void acpi_restore_state_mem(void)
 {
-	zap_low_mappings();
 }
 
 /**
diff -puN arch/i386/mm/init.c~i386_direct_mapping arch/i386/mm/init.c
--- linux-2.6.17-rc4-mm1/arch/i386/mm/init.c~i386_direct_mapping	2006-05-17 09:03:39.000000000 +0800
+++ linux-2.6.17-rc4-mm1-root/arch/i386/mm/init.c	2006-05-18 07:11:10.000000000 +0800
@@ -386,7 +386,7 @@ static void __init pagetable_init (void)
 #endif
 }
 
-#ifdef CONFIG_SOFTWARE_SUSPEND
+#if defined(CONFIG_SOFTWARE_SUSPEND) || defined(CONFIG_ACPI_SLEEP)
 /*
  * Swap suspend & friends need this for resume because things like the intel-agp
  * driver might have split up a kernel 4MB mapping.
@@ -422,18 +422,7 @@ void zap_low_mappings (void)
 #else
 		set_pgd(swapper_pg_dir+i, __pgd(0));
 #endif
-	/*
-	 * We can be called at suspend/resume time, with local interrupts
-	 * disabled.  But flush_tlb_all() requires that local interrupts be
-	 * enabled.
-	 *
-	 * Happily, the APs are not yet started, so we can use local_flush_tlb()
-	 * in that case
-	 */
-	if (num_online_cpus() == 1)
-		local_flush_tlb();
-	else
-		flush_tlb_all();
+	flush_tlb_all();
 }
 
 static int disable_nx __initdata = 0;
_

Re: [PATCH] don't use flush_tlb_all in suspend time

[Pavel Machek]

Hi!

> > > > > @@ -420,7 +421,14 @@ void zap_low_mappings (void)
> > > > >  #else
> > > > >  		set_pgd(swapper_pg_dir+i, __pgd(0));
> > > > >  #endif
> > > > > -	if (cpus_weight(cpu_online_map) == 1)
> > > > > +	/*
> > > > > +	 * We can be called at suspend/resume time, with local interrupts
> > > > > +	 * disabled.  But flush_tlb_all() requires that local interrupts be
> > > > > +	 * enabled.
> > > > > +	 *
> > > > > +	 * Happily, the APs are not yet started, so we can use local_flush_tlb()	 * in that case
> > > > > +	 */
> > > > > +	if (num_online_cpus() == 1)
> > > > >  		local_flush_tlb();
> > > > >  	else
> > > > >  		flush_tlb_all();
> > > > 
> > > > But this still scares. It means calling convention is "may enable
> > > > interrupts with >1 cpu, may not with == 1 cpu". 
> > > Below patch should make things clean. How do you think?
> > 
> > Nice...
> > 
> > Could we perhaps reuse swsusp_pg_dir (just make it used for swsusp &
> > suspend-to-ram) to save a bit more code? It is in arch/i386/mm/init.c
> Ok, I guess this is what you want.

Yes, thanks a lot for patience.

> Signed-off-by: Shaohua Li <shaohua.li@intel.com>

Acked-by: Pavel Machek <pavel@suse.cz>

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html