Messages in this thread | | | Subject | Re: [PATCH] don't use flush_tlb_all in suspend time | From | Shaohua Li <> | Date | Sun, 30 Apr 2006 15:19:04 +0800 |
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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>
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