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 <[email protected]> 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 <[email protected]>
---
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;
_
-
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