Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH] Fix __pfn_to_page(pfn) for CONFIG_DISCONTIGMEM=y | Date | Sat, 8 Nov 2008 14:12:21 +0100 |
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On Saturday, 8 of November 2008, Pavel Machek wrote: > Hi! > > > This would be good to have in .28 IMO. > > Actually, this makes sense even for .27-stable, AFAICT.
Yes, it does, but it has to be merged first. :-)
> > From: Rafael J. Wysocki <rjw@sisk.pl> > > Subject: Fix __pfn_to_page(pfn) for CONFIG_DISCONTIGMEM=y > > > > Fix macro __pfn_to_page(pfn) so that it doesn't evaluate its > > argument twice in the CONFIG_DISCONTIGMEM=y case, because 'pfn' may > > be a result of a funtion call having side effects. > > function call?
Oh, I mean __pfn_to_page(a_function(something)), where a_function() does more than just computing the result.
> > For example, the hibernation code applies pfn_to_page(pfn) to the > > result of a function returning the pfn corresponding to the next set > > bit in a bitmap and the current bit position is modified on each > > call. This leads to "interesting" failures for CONFIG_DISCONTIGMEM=y > > due to the current behavior of __pfn_to_page(pfn). > > > > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> > > Cc: Pavel Machek <pavel@suse.cz> > > Acked-by: Pavel Machek <pavel@suse.cz> > > > > include/asm-generic/memory_model.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > Index: linux-2.6/include/asm-generic/memory_model.h > > =================================================================== > > --- linux-2.6.orig/include/asm-generic/memory_model.h > > +++ linux-2.6/include/asm-generic/memory_model.h > > @@ -34,7 +34,7 @@ > > > > #define __pfn_to_page(pfn) \ > > ({ unsigned long __pfn = (pfn); \ > > - unsigned long __nid = arch_pfn_to_nid(pfn); \ > > + unsigned long __nid = arch_pfn_to_nid(__pfn); \ > > NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\ > > })
Thanks, Rafael
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