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

[Yinghai Lu]

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

YH
[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,
 				 PAGE_SIZE);
 	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);
 	register_bootmem_low_pages(max_low_pfn);
 	early_res_to_bootmem(0, max_low_pfn<<PAGE_SHIFT);
 	reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT);