On Thu, Jul 06, 2006 at 01:44:42PM -0700, David Brownell wrote: > > > > Of course it needs fixing ... it's a bug, also a regression. > > > > > > My question is where to fix... > > > > Well, I meant replacing the memcpy() in copy_data_pages with an open coded > > copying loop. That should be enough to fix the problem. > > One like this? Yes, it works. The slower speed shouldn't be > much of an issue here. (Though I'm glad that something in RC1 > has gotten rid of that slowdown in reading/writing snapshots.) Why not just use __memcpy instead? Which should be safe on all archs to do the simplest possible memcpy. Signed-off-by: Dave Jones <davej at redhat.com> --- linux-2.6/kernel/power/snapshot.c~ 2006-07-06 16:56:11.000000000 -0400 +++ linux-2.6/kernel/power/snapshot.c 2006-07-06 16:59:11.000000000 -0400 @@ -230,8 +230,9 @@ static void copy_data_pages(struct pbe * page = pfn_to_page(zone_pfn + zone->zone_start_pfn); BUG_ON(!pbe); pbe->orig_address = (unsigned long)page_address(page); - /* copy_page is not usable for copying task structs. */ - memcpy((void *)pbe->address, (void *)pbe->orig_address, PAGE_SIZE); + /* copy_page is not usable for copying task structs. + * neither is memcpy on some cpus */ + __memcpy((void *)pbe->address, (void *)pbe->orig_address, PAGE_SIZE); pbe = pbe->next; } } -- http://www.codemonkey.org.uk
