Revert "fb_defio: fix for non-dirty ptes" (3f505ca4) · Commits · 戴 / test

drivers/video/fb_defio.c

+8 −32

Original line number	Diff line number	Diff line
		@@ -155,41 +155,25 @@ static void fb_deferred_io_work(struct work_struct *work)
		{
		struct fb_info *info = container_of(work, struct fb_info,
		deferred_work.work);
		struct list_head node, next;
		struct page *cur;
		struct fb_deferred_io *fbdefio = info->fbdefio;
		struct page page, tmp_page;
		struct list_head node, tmp_node;
		struct list_head non_dirty;

		INIT_LIST_HEAD(&non_dirty);

		/* here we mkclean the pages, then do all deferred IO */
		mutex_lock(&fbdefio->lock);
		list_for_each_entry_safe(page, tmp_page, &fbdefio->pagelist, lru) {
		lock_page(page);
		/*
		* The workqueue callback can be triggered after a
		* ->page_mkwrite() call but before the PTE has been marked
		* dirty. In this case page_mkclean() won't "rearm" the page.
		*
		* To avoid this, remove those "non-dirty" pages from the
		* pagelist before calling the driver's callback, then add
		* them back to get processed on the next work iteration.
		* At that time, their PTEs will hopefully be dirty for real.
		*/
		if (!page_mkclean(page))
		list_move_tail(&page->lru, &non_dirty);
		unlock_page(page);
		list_for_each_entry(cur, &fbdefio->pagelist, lru) {
		lock_page(cur);
		page_mkclean(cur);
		unlock_page(cur);
		}

		/* driver's callback with pagelist */
		fbdefio->deferred_io(info, &fbdefio->pagelist);

		/* clear the list... */
		list_for_each_safe(node, tmp_node, &fbdefio->pagelist) {
		/* clear the list */
		list_for_each_safe(node, next, &fbdefio->pagelist) {
		list_del(node);
		}
		/* ... and add back the "non-dirty" pages to the list */
		list_splice_tail(&non_dirty, &fbdefio->pagelist);
		mutex_unlock(&fbdefio->lock);
		}

		@@ -218,7 +202,6 @@ EXPORT_SYMBOL_GPL(fb_deferred_io_open);
		void fb_deferred_io_cleanup(struct fb_info *info)
		{
		struct fb_deferred_io *fbdefio = info->fbdefio;
		struct list_head node, tmp_node;
		struct page *page;
		int i;

		@@ -226,13 +209,6 @@ void fb_deferred_io_cleanup(struct fb_info *info)
		cancel_delayed_work(&info->deferred_work);
		flush_scheduled_work();

		/* the list may have still some non-dirty pages at this point */
		mutex_lock(&fbdefio->lock);
		list_for_each_safe(node, tmp_node, &fbdefio->pagelist) {
		list_del(node);
		}
		mutex_unlock(&fbdefio->lock);

		/* clear out the mapping that we setup */
		for (i = 0 ; i < info->fix.smem_len; i += PAGE_SIZE) {
		page = fb_deferred_io_page(info, i);

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