Messages in this thread Patch in this message | | | Date | Mon, 10 Sep 2012 13:43:23 -0400 | From | Cyril Chemparathy <> | Subject | Re: [PATCH v2 16/22] ARM: mm: cleanup checks for membank overlap with vmalloc area |
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On 8/12/2012 12:36 AM, Nicolas Pitre wrote: > On Fri, 10 Aug 2012, Cyril Chemparathy wrote: > >> On Keystone platforms, physical memory is entirely outside the 32-bit >> addressible range. Therefore, the (bank->start > ULONG_MAX) check below marks >> the entire system memory as highmem, and this causes unpleasentness all over. >> >> This patch eliminates the extra bank start check (against ULONG_MAX) by >> checking bank->start against the physical address corresponding to vmalloc_min >> instead. >> >> In the process, this patch also cleans up parts of the highmem sanity check >> code by removing what has now become a redundant check for banks that entirely >> overlap with the vmalloc range. > > Are you sure of this? The code that you removed not only checks for > banks that fall into the vmalloc area, but it also skipp them. This is > now lost. >
I almost missed out on this email...
The check is not quite lost, we still have the following in the !CONFIG_HIGHMEM block:
if (highmem) { printk(...); continue; }
The change is that highmem is now set outside the #ifdef when (bank->start >= vmalloc_limit), and therefore the check is truly redundant.
>> Signed-off-by: Cyril Chemparathy <cyril@ti.com> >> Signed-off-by: Vitaly Andrianov <vitalya@ti.com> >> --- >> arch/arm/mm/mmu.c | 19 +------------------ >> 1 file changed, 1 insertion(+), 18 deletions(-) >> >> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c >> index f764c03..3d685c6 100644 >> --- a/arch/arm/mm/mmu.c >> +++ b/arch/arm/mm/mmu.c >> @@ -901,15 +901,12 @@ void __init sanity_check_meminfo(void) >> struct membank *bank = &meminfo.bank[j]; >> *bank = meminfo.bank[i]; >> >> - if (bank->start > ULONG_MAX) >> - highmem = 1; >> - >> -#ifdef CONFIG_HIGHMEM >> if (bank->start >= vmalloc_limit) >> highmem = 1; >> >> bank->highmem = highmem; >> >> +#ifdef CONFIG_HIGHMEM >> /* >> * Split those memory banks which are partially overlapping >> * the vmalloc area greatly simplifying things later. >> @@ -932,8 +929,6 @@ void __init sanity_check_meminfo(void) >> bank->size = vmalloc_limit - bank->start; >> } >> #else >> - bank->highmem = highmem; >> - >> /* >> * Highmem banks not allowed with !CONFIG_HIGHMEM. >> */ >> @@ -946,18 +941,6 @@ void __init sanity_check_meminfo(void) >> } >> >> /* >> - * Check whether this memory bank would entirely overlap >> - * the vmalloc area. >> - */ >> - if (bank->start >= vmalloc_limit) { >> - printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx " >> - "(vmalloc region overlap).\n", >> - (unsigned long long)bank->start, >> - (unsigned long long)bank->start + bank->size - 1); >> - continue; >> - } >> - >> - /* >> * Check whether this memory bank would partially overlap >> * the vmalloc area. >> */ >> -- >> 1.7.9.5 >>
-- Thanks - Cyril
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