about doing this.
The idea is, first at flush_dcache_page() time, if
- page->mapping->i_mmap is an empty tree and ->i_mmap_nonlinear
- an empty list, just mark the architecture private page flag bit.
- Later, in update_mmu_cache(), a check is made of this flag bit,
- and if set the flush is done and the flag bit is cleared.
+ page->mapping->i_mmap is an empty tree, just mark the architecture
+ private page flag bit. Later, in update_mmu_cache(), a check is
+ made of this flag bit, and if set the flush is done and the flag
+ bit is cleared.
IMPORTANT NOTE: It is often important, if you defer the flush,
that the actual flush occurs on the same CPU