Bug#676360: [PATCH] thp: avoid atomic64_read in pmd_read_atomic for 32bit PAE\

2012-06-09 Thread Konrad Rzeszutek Wilk
On Thu, Jun 07, 2012 at 11:00:33PM +0200, Andrea Arcangeli wrote: > In the x86 32bit PAE CONFIG_TRANSPARENT_HUGEPAGE=y case while holding > the mmap_sem for reading, cmpxchg8b cannot be used to read pmd > contents under Xen. > > So instead of dealing only with "consistent" pmdvals in > pmd_none_or

Bug#676360: [PATCH] thp: avoid atomic64_read in pmd_read_atomic for 32bit PAE

2012-06-07 Thread Andrea Arcangeli
In the x86 32bit PAE CONFIG_TRANSPARENT_HUGEPAGE=y case while holding the mmap_sem for reading, cmpxchg8b cannot be used to read pmd contents under Xen. So instead of dealing only with "consistent" pmdvals in pmd_none_or_trans_huge_or_clear_bad() (which would be conceptually simpler) we let pmd_no