Re: Suspected regression in "x86: extend e820 ealy_res support 32bit"

From: Yinghai Lu
Date: Wed May 21 2008 - 16:36:36 EST

On Wed, May 21, 2008 at 11:19 AM, Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:
> I'm seeing a crash in current x86.git tip/auto-latest when booting under
> Xen. The crash is rather early, but it's in __alloc_bootmem_core() in the
> final memset clear. Apparently the allocator is returning a bad page.
> This points to changes in the setup of the bootmem allocator, and the
> changes "x86: extend e820 ealy_res support 32bit" make to
> arch/x86/kernel/setup_32.c:setup_bootmem_allocator() looks like the most
> likely suspect. Unfortunately its a rather large patch which is not easy to
> revert, so I haven't actually confirmed this yet.

thanks. please check the attached patch

[PATCH] x86: bootmap size fix for 32 bit

Jeremy Fitzhardinge found
x86: extend e820 ealy_res support 32bit
cause regression...

in setup_bootmem_allocator

Signed-off-by: Yinghai Lu <yhlu.kernel@xxxxxxxxx>

diff --git a/arch/x86/kernel/setup_32.c b/arch/x86/kernel/setup_32.c
index f38d840..938c7b3 100644
--- a/arch/x86/kernel/setup_32.c
+++ b/arch/x86/kernel/setup_32.c
@@ -566,17 +566,22 @@ static void __init relocate_initrd(void)

void __init setup_bootmem_allocator(void)
+ unsigned long bootmap_pages;
unsigned long bootmap_size, bootmap;
* Initialize the boot-time allocator (with low memory only):
- bootmap_size = bootmem_bootmap_pages(max_low_pfn)<<PAGE_SHIFT;
+ bootmap_pages = bootmem_bootmap_pages(max_low_pfn)<<PAGE_SHIFT;
bootmap = find_e820_area(min_low_pfn<<PAGE_SHIFT,
- max_low_pfn<<PAGE_SHIFT, bootmap_size,
+ max_low_pfn<<PAGE_SHIFT,
+ bootmap_pages<<PAGE_SHIFT,
if (bootmap == -1L)
panic("Cannot find bootmem map of size %ld\n", bootmap_size);
bootmap_size = init_bootmem(bootmap >> PAGE_SHIFT, max_low_pfn);
+ printk(KERN_INFO " bootmap [%016lx - %016lx] pages %lx\n",
+ bootmap, bootmap + bootmap_size - 1,
+ bootmap_pages);
early_res_to_bootmem(0, max_low_pfn<<PAGE_SHIFT);
reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT);