> page_mkclean_one is used to clear the dirty bit and to set the write > protect bit of a pte. In additions it returns true if the pte either > has been dirty or if it has been writable. As far as I can see the > function should return true only if the pte has been dirty, or page > writeback will needlessly write a clean page.
There are some weird cases, like for example get_user_pages(), when the pte takes a write fault and the page is modified, but the pte doesn't become dirty, because the page is written through the kernel mapping. In the get_user_pages() case the page itself is dirtied, so your patch probably doesn't break that. But I'm not sure if there aren't similar cases like that that the pte_write() check is taking care of. And anyway if the dirty page tracking works correctly, your patch won't optimize anything, since the pte will _only_ become writable if the page was dirtied. So in fact normally pte_dirty() and pte_write() should be equivalent, except for some weird cases. Miklos - 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/
