On 10/13/2010 11:37 PM, Ingo Molnar wrote: > > * Yinghai Lu <yinghai@xxxxxxxxxx> wrote: > >> On 10/13/2010 10:57 PM, Ingo Molnar wrote: >>> >>> * tip-bot for Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote: >>> >>>> Commit-ID: 859ee4f57fb4e91de8439496f62eb996f4a28ca8 >>>> Gitweb: http://git.kernel.org/tip/859ee4f57fb4e91de8439496f62eb996f4a28ca8 >>>> Author: Jeremy Fitzhardinge <jeremy@xxxxxxxx> >>>> AuthorDate: Wed, 13 Oct 2010 16:34:15 -0700 >>>> Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> >>>> CommitDate: Wed, 13 Oct 2010 17:09:59 -0700 >>>> >>>> x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S >>>> >>>> head_64.S maps up to 512 MiB, but that is not necessarity true for >>>> other entry paths, such as Xen. >>> please fold following patch into 859ee4f57fb4e91de8439496f62eb996f4a28ca8 Thanks Yinghai [PATCH] x86_64: Set max_pfn_mapped in x86_64_start_kernel Ingo found: [ 0.000000] init_memory_mapping: 0000000000000000-000000003fff0000 [ 0.000000] 0000000000 - 003fe00000 page 2M [ 0.000000] 003fe00000 - 003fff0000 page 4k [ 0.000000] Kernel panic - not syncing: Cannot find space for the kernel page tables [ 0.000000] Pid: 0, comm: swapper Not tainted 2.6.36-rc7-tip+ #49192 [ 0.000000] Call Trace: [ 0.000000] [<ffffffff8156c73f>] panic+0x8c/0x192 [ 0.000000] [<ffffffff8156c881>] ? printk+0x3c/0x3e [ 0.000000] [<ffffffff8154ec40>] init_memory_mapping+0x372/0x506 [ 0.000000] [<ffffffff819053ed>] ? memblock_x86_reserve_range+0x7c/0x83 [ 0.000000] [<ffffffff818f2f3d>] setup_arch+0x5a3/0xa68 [ 0.000000] [<ffffffff8156c881>] ? printk+0x3c/0x3e [ 0.000000] [<ffffffff81061135>] ? clockevents_register_notifier+0x3e/0x4a [ 0.000000] [<ffffffff818ef9e1>] start_kernel+0x83/0x36e [ 0.000000] [<ffffffff818ef2a8>] x86_64_start_reservations+0xb8/0xbc [ 0.000000] [<ffffffff818ef393>] x86_64_start_kernel+0xe7/0xee caused by: | 859ee4f: x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S it turns out max_pfn_mapped is in .bss section. So We need to set that after bss get cleared. that is safe because xen don't call x86_64_start_kernel() Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> --- arch/x86/kernel/head64.c | 2 ++ arch/x86/kernel/head_64.S | 2 -- 2 files changed, 2 insertions(+), 2 deletions(-) Index: linux-2.6/arch/x86/kernel/head64.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/head64.c +++ linux-2.6/arch/x86/kernel/head64.c @@ -80,6 +80,8 @@ void __init x86_64_start_kernel(char * r /* Cleanup the over mapped high alias */ cleanup_highmap(); + max_pfn_mapped = KERNEL_IMAGE_SIZE >> PAGE_SHIFT; + for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) { #ifdef CONFIG_EARLY_PRINTK set_intr_gate(i, &early_idt_handlers[i]); Index: linux-2.6/arch/x86/kernel/head_64.S =================================================================== --- linux-2.6.orig/arch/x86/kernel/head_64.S +++ linux-2.6/arch/x86/kernel/head_64.S @@ -141,8 +141,6 @@ ident_complete: addq %rbp, trampoline_level4_pgt + (511*8)(%rip) #endif - movq $KERNEL_IMAGE_SIZE / PAGE_SIZE, max_pfn_mapped(%rip) - /* Due to ENTRY(), sometimes the empty space gets filled with * zeros. Better take a jmp than relying on empty space being * filled with 0x90 (nop) -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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