Messages in this thread Patch in this message | | | Date | Sat, 29 Apr 2006 23:57:21 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] don't use flush_tlb_all in suspend time |
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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(); } _ - 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/
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