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

From: Pavel Machek
Date: Sun Apr 30 2006 - 02:45:28 EST


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!
-
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