lkml.org 
[lkml]   [2006]   [May]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
SubjectRe: [PATCH] don't use flush_tlb_all in suspend time
From
Date
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;
_
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-05-19 03:19    [W:0.036 / U:1.448 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site