Re: [patch 006/198] arm: add comment about max_low_pfn/max_pfn
On Wed, Apr 13, 2005 at 11:10:35AM +0800, Coywolf Qi Hunt wrote: > I told rmk about this long time ago. The kernel is a mess of DMA masks and maximum PFNs which all assume that memory always starts at zero, which I've mentioned before as well. I might see about fixing this up properly when it causes real problems, but until then its better to document the behaviour. -- Russell King Linux kernel2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 006/198] arm: add comment about max_low_pfn/max_pfn
FYI http://lkml.org/lkml/2004/6/29/57 On 4/13/05, Coywolf Qi Hunt <[EMAIL PROTECTED]> wrote: > I told rmk about this long time ago. > > On 4/12/05, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > > > > From: Russell King <[EMAIL PROTECTED]> > > > > Oddly, max_low_pfn/max_pfn end up being the number of pages in the system, > > rather than the maximum PFN on ARM. This doesn't seem to cause any > > problems, > > so just add a note about it. > > > > Signed-off-by: Russell King <[EMAIL PROTECTED]> > > Signed-off-by: Andrew Morton <[EMAIL PROTECTED]> > > --- > > > > 25-akpm/arch/arm/mm/init.c |3 +++ > > 1 files changed, 3 insertions(+) > > > > diff -puN arch/arm/mm/init.c~arm-add-comment-about-max_low_pfn-max_pfn > > arch/arm/mm/init.c > > --- 25/arch/arm/mm/init.c~arm-add-comment-about-max_low_pfn-max_pfn > > 2005-04-12 03:21:04.967381744 -0700 > > +++ 25-akpm/arch/arm/mm/init.c 2005-04-12 03:21:04.971381136 -0700 > > @@ -223,6 +223,9 @@ find_memend_and_nodes(struct meminfo *mi > > * This doesn't seem to be used by the Linux memory > > * manager any more. If we can get rid of it, we > > * also get rid of some of the stuff above as well. > > +* > > +* Note: max_low_pfn and max_pfn reflect the number > > +* of _pages_ in the system, not the maximum PFN. > > */ > > max_low_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET); > > max_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET); > > _ > > -- > Coywolf Qi Hunt > http://sosdg.org/~coywolf/ > -- Coywolf Qi Hunt http://sosdg.org/~coywolf/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 006/198] arm: add comment about max_low_pfn/max_pfn
I told rmk about this long time ago. On 4/12/05, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > > From: Russell King <[EMAIL PROTECTED]> > > Oddly, max_low_pfn/max_pfn end up being the number of pages in the system, > rather than the maximum PFN on ARM. This doesn't seem to cause any problems, > so just add a note about it. > > Signed-off-by: Russell King <[EMAIL PROTECTED]> > Signed-off-by: Andrew Morton <[EMAIL PROTECTED]> > --- > > 25-akpm/arch/arm/mm/init.c |3 +++ > 1 files changed, 3 insertions(+) > > diff -puN arch/arm/mm/init.c~arm-add-comment-about-max_low_pfn-max_pfn > arch/arm/mm/init.c > --- 25/arch/arm/mm/init.c~arm-add-comment-about-max_low_pfn-max_pfn > 2005-04-12 03:21:04.967381744 -0700 > +++ 25-akpm/arch/arm/mm/init.c 2005-04-12 03:21:04.971381136 -0700 > @@ -223,6 +223,9 @@ find_memend_and_nodes(struct meminfo *mi > * This doesn't seem to be used by the Linux memory > * manager any more. If we can get rid of it, we > * also get rid of some of the stuff above as well. > +* > +* Note: max_low_pfn and max_pfn reflect the number > +* of _pages_ in the system, not the maximum PFN. > */ > max_low_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET); > max_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET); > _ -- Coywolf Qi Hunt http://sosdg.org/~coywolf/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[patch 006/198] arm: add comment about max_low_pfn/max_pfn
From: Russell King <[EMAIL PROTECTED]> Oddly, max_low_pfn/max_pfn end up being the number of pages in the system, rather than the maximum PFN on ARM. This doesn't seem to cause any problems, so just add a note about it. Signed-off-by: Russell King <[EMAIL PROTECTED]> Signed-off-by: Andrew Morton <[EMAIL PROTECTED]> --- 25-akpm/arch/arm/mm/init.c |3 +++ 1 files changed, 3 insertions(+) diff -puN arch/arm/mm/init.c~arm-add-comment-about-max_low_pfn-max_pfn arch/arm/mm/init.c --- 25/arch/arm/mm/init.c~arm-add-comment-about-max_low_pfn-max_pfn 2005-04-12 03:21:04.967381744 -0700 +++ 25-akpm/arch/arm/mm/init.c 2005-04-12 03:21:04.971381136 -0700 @@ -223,6 +223,9 @@ find_memend_and_nodes(struct meminfo *mi * This doesn't seem to be used by the Linux memory * manager any more. If we can get rid of it, we * also get rid of some of the stuff above as well. +* +* Note: max_low_pfn and max_pfn reflect the number +* of _pages_ in the system, not the maximum PFN. */ max_low_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET); max_pfn = memend_pfn - O_PFN_DOWN(PHYS_OFFSET); _ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
