Re: Linux 2.6.27-rc5: System boot regression caused by commit a2bd7274b47124d2fc4dfdb8c0591f545ba749dd

Rafael J. Wysocki
2008-08-29T22:26:56Z

On Friday, 29 of August 2008, Linus Torvalds wrote:
>
> On Fri, 29 Aug 2008, Rafael J. Wysocki wrote:
> >
> > Bisection turned up commit a2bd7274b47124d2fc4dfdb8c0591f545ba749dd as the culprit:
> >
> > commit a2bd7274b47124d2fc4dfdb8c0591f545ba749dd
> > Author: Yinghai Lu <yhlu.kernel@gmail.com>
> > Date: Mon Aug 25 00:56:08 2008 -0700
> >
> > x86: fix HPET regression in 2.6.26 versus 2.6.25, check hpet against BAR, v3
> >
> > Reverting this commit helps.
>
> Heh, interesting, since we were talking about reverting that one for other
> reasons entirely.
>
> See the thread "x86: split e820 reserved entries record to late" (yeah, I
> know that subject isn't very grammatical or sensible) for some patches
> worth trying _after_ you've reverted that one.
>
> Anyway, clearly that commit needs to be reverted regardless, so I'll do
> the revert. Can you please test the appended test-patch by Yinghai on top
> of the revert?
>
> (This is not the final version, but it should be sufficient to be tested)

This works, thanks.

> And if you have the whole dmesg, that would be useful.

dmesg from -rc5 with the offending commit reverted and with the patch
below applied is at:

http://www.sisk.pl/kernel/debug/mainline/2.6.27-rc5/2.6.27-rc5-git.log

Thanks,
Rafael

> ---
> From: Yinghai Lu <yhlu.kernel@gmail.com>
> Subject: [PATCH] x86: split e820 reserved entries record to late v3
> Date: Thu, 28 Aug 2008 17:41:29 -0700
>
> so could let BAR res register at first, or even pnp?
>
> v2: insert e820 reserve resources before pnp_system_init
> v3: fix merging problem in tip/x86/core
> please drop the one in tip/x86/core use this one instead
>
> Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
>
> ---
> arch/x86/kernel/e820.c | 20 ++++++++++++++++++--
> arch/x86/pci/i386.c | 3 +++
> include/asm-x86/e820.h | 1 +
> 3 files changed, 22 insertions(+), 2 deletions(-)
>
> Index: linux-2.6/arch/x86/kernel/e820.c
> ===================================================================
> --- linux-2.6.orig/arch/x86/kernel/e820.c
> +++ linux-2.6/arch/x86/kernel/e820.c
> @@ -1271,13 +1271,15 @@ static inline const char *e820_type_to_s
> /*
> * Mark e820 reserved areas as busy for the resource manager.
> */
> +struct resource __initdata *e820_res;
> void __init e820_reserve_resources(void)
> {
> int i;
> - struct resource *res;
> u64 end;
> + struct resource *res;
>
> res = alloc_bootmem_low(sizeof(struct resource) * e820.nr_map);
> + e820_res = res;
> for (i = 0; i < e820.nr_map; i++) {
> end = e820.map[i].addr + e820.map[i].size - 1;
> #ifndef CONFIG_RESOURCES_64BIT
> @@ -1291,7 +1293,8 @@ void __init e820_reserve_resources(void)
> res->end = end;
>
> res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
> - insert_resource(&iomem_resource, res);
> + if (e820.map[i].type != E820_RESERVED || res->start < (1ULL<<20))
> + insert_resource(&iomem_resource, res);
> res++;
> }
>
> @@ -1303,6 +1306,19 @@ void __init e820_reserve_resources(void)
> }
> }
>
> +void __init e820_reserve_resources_late(void)
> +{
> + int i;
> + struct resource *res;
> +
> + res = e820_res;
> + for (i = 0; i < e820.nr_map; i++) {
> + if (e820.map[i].type == E820_RESERVED && res->start >= (1ULL<<20))
> + insert_resource(&iomem_resource, res);
> + res++;
> + }
> +}
> +
> char *__init default_machine_specific_memory_setup(void)
> {
> char *who = "BIOS-e820";
> Index: linux-2.6/arch/x86/pci/i386.c
> ===================================================================
> --- linux-2.6.orig/arch/x86/pci/i386.c
> +++ linux-2.6/arch/x86/pci/i386.c
> @@ -33,6 +33,7 @@
> #include <linux/bootmem.h>
>
> #include <asm/pat.h>
> +#include <asm/e820.h>
>
> #include "pci.h"
>
> @@ -230,6 +231,8 @@ void __init pcibios_resource_survey(void
> pcibios_allocate_bus_resources(&pci_root_buses);
> pcibios_allocate_resources(0);
> pcibios_allocate_resources(1);
> +
> + e820_reserve_resources_late();
> }
>
> /**
> Index: linux-2.6/include/asm-x86/e820.h
> ===================================================================
> --- linux-2.6.orig/include/asm-x86/e820.h
> +++ linux-2.6/include/asm-x86/e820.h
> @@ -122,6 +122,7 @@ extern void e820_register_active_regions
> extern u64 e820_hole_size(u64 start, u64 end);
> extern void finish_e820_parsing(void);
> extern void e820_reserve_resources(void);
> +extern void e820_reserve_resources_late(void);
> extern void setup_memory_map(void);
> extern char *default_machine_specific_memory_setup(void);
> extern char *machine_specific_memory_setup(void);
>
>
>