Commit c24f21bd authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
Browse files

[PATCH] zoned vm counters: remove useless struct wbs 



Remove writeback state

We can remove some functions now that were needed to calculate the page state
for writeback control since these statistics are now directly available.

Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent d2c5e30c

mm/page-writeback.c

+34 −51
Original line number Diff line number Diff line
@@ -99,23 +99,6 @@ EXPORT_SYMBOL(laptop_mode); 


static void background_writeout(unsigned long _min_pages);



struct writeback_state

{

	unsigned long nr_dirty;

	unsigned long nr_unstable;

	unsigned long nr_mapped;

	unsigned long nr_writeback;

};



static void get_writeback_state(struct writeback_state *wbs)

{

	wbs->nr_dirty = global_page_state(NR_FILE_DIRTY);

	wbs->nr_unstable = global_page_state(NR_UNSTABLE_NFS);

	wbs->nr_mapped = global_page_state(NR_FILE_MAPPED) +

				global_page_state(NR_ANON_PAGES);

	wbs->nr_writeback = global_page_state(NR_WRITEBACK);

}



/*

 * Work out the current dirty-memory clamping and background writeout

 * thresholds.
@@ -134,7 +117,7 @@ static void get_writeback_state(struct writeback_state *wbs) 
 * clamping level.

 */

static void

get_dirty_limits(struct writeback_state *wbs, long *pbackground, long *pdirty,

get_dirty_limits(long *pbackground, long *pdirty,

					struct address_space *mapping)

{

	int background_ratio;		/* Percentages */
@@ -145,8 +128,6 @@ get_dirty_limits(struct writeback_state *wbs, long *pbackground, long *pdirty, 
	unsigned long available_memory = total_pages;

	struct task_struct *tsk;



	get_writeback_state(wbs);



#ifdef CONFIG_HIGHMEM

	/*

	 * If this mapping can only allocate from low memory,
@@ -157,7 +138,9 @@ get_dirty_limits(struct writeback_state *wbs, long *pbackground, long *pdirty, 
#endif





	unmapped_ratio = 100 - (wbs->nr_mapped * 100) / total_pages;

	unmapped_ratio = 100 - ((global_page_state(NR_FILE_MAPPED) +

				global_page_state(NR_ANON_PAGES)) * 100) /

					total_pages;



	dirty_ratio = vm_dirty_ratio;

	if (dirty_ratio > unmapped_ratio / 2)
@@ -190,7 +173,6 @@ get_dirty_limits(struct writeback_state *wbs, long *pbackground, long *pdirty, 
 */

static void balance_dirty_pages(struct address_space *mapping)

{

	struct writeback_state wbs;

	long nr_reclaimable;

	long background_thresh;

	long dirty_thresh;
@@ -208,10 +190,11 @@ static void balance_dirty_pages(struct address_space *mapping) 
			.range_cyclic	= 1,

		};



		get_dirty_limits(&wbs, &background_thresh,

					&dirty_thresh, mapping);

		nr_reclaimable = wbs.nr_dirty + wbs.nr_unstable;

		if (nr_reclaimable + wbs.nr_writeback <= dirty_thresh)

		get_dirty_limits(&background_thresh, &dirty_thresh, mapping);

		nr_reclaimable = global_page_state(NR_FILE_DIRTY) +

					global_page_state(NR_UNSTABLE_NFS);

		if (nr_reclaimable + global_page_state(NR_WRITEBACK) <=

			dirty_thresh)

				break;



		if (!dirty_exceeded)
@@ -225,10 +208,13 @@ static void balance_dirty_pages(struct address_space *mapping) 
		 */

		if (nr_reclaimable) {

			writeback_inodes(&wbc);

			get_dirty_limits(&wbs, &background_thresh,

			get_dirty_limits(&background_thresh,

					 	&dirty_thresh, mapping);

			nr_reclaimable = wbs.nr_dirty + wbs.nr_unstable;

			if (nr_reclaimable + wbs.nr_writeback <= dirty_thresh)

			nr_reclaimable = global_page_state(NR_FILE_DIRTY) +

					global_page_state(NR_UNSTABLE_NFS);

			if (nr_reclaimable +

				global_page_state(NR_WRITEBACK)

					<= dirty_thresh)

						break;

			pages_written += write_chunk - wbc.nr_to_write;

			if (pages_written >= write_chunk)
@@ -237,7 +223,8 @@ static void balance_dirty_pages(struct address_space *mapping) 
		blk_congestion_wait(WRITE, HZ/10);

	}



	if (nr_reclaimable + wbs.nr_writeback <= dirty_thresh && dirty_exceeded)

	if (nr_reclaimable + global_page_state(NR_WRITEBACK)

		<= dirty_thresh && dirty_exceeded)

			dirty_exceeded = 0;



	if (writeback_in_progress(bdi))
@@ -300,12 +287,11 @@ EXPORT_SYMBOL(balance_dirty_pages_ratelimited_nr); 


void throttle_vm_writeout(void)

{

	struct writeback_state wbs;

	long background_thresh;

	long dirty_thresh;



        for ( ; ; ) {

		get_dirty_limits(&wbs, &background_thresh, &dirty_thresh, NULL);

		get_dirty_limits(&background_thresh, &dirty_thresh, NULL);



                /*

                 * Boost the allowable dirty threshold a bit for page
@@ -313,7 +299,8 @@ void throttle_vm_writeout(void) 
                 */

                dirty_thresh += dirty_thresh / 10;      /* wheeee... */



                if (wbs.nr_unstable + wbs.nr_writeback <= dirty_thresh)

                if (global_page_state(NR_UNSTABLE_NFS) +

			global_page_state(NR_WRITEBACK) <= dirty_thresh)

                        	break;

                blk_congestion_wait(WRITE, HZ/10);

        }
@@ -337,12 +324,12 @@ static void background_writeout(unsigned long _min_pages) 
	};



	for ( ; ; ) {

		struct writeback_state wbs;

		long background_thresh;

		long dirty_thresh;



		get_dirty_limits(&wbs, &background_thresh, &dirty_thresh, NULL);

		if (wbs.nr_dirty + wbs.nr_unstable < background_thresh

		get_dirty_limits(&background_thresh, &dirty_thresh, NULL);

		if (global_page_state(NR_FILE_DIRTY) +

			global_page_state(NR_UNSTABLE_NFS) < background_thresh

				&& min_pages <= 0)

			break;

		wbc.encountered_congestion = 0;
@@ -366,12 +353,9 @@ static void background_writeout(unsigned long _min_pages) 
 */

int wakeup_pdflush(long nr_pages)

{

	if (nr_pages == 0) {

		struct writeback_state wbs;



		get_writeback_state(&wbs);

		nr_pages = wbs.nr_dirty + wbs.nr_unstable;

	}

	if (nr_pages == 0)

		nr_pages = global_page_state(NR_FILE_DIRTY) +

				global_page_state(NR_UNSTABLE_NFS);

	return pdflush_operation(background_writeout, nr_pages);

}
@@ -402,7 +386,6 @@ static void wb_kupdate(unsigned long arg) 
	unsigned long start_jif;

	unsigned long next_jif;

	long nr_to_write;

	struct writeback_state wbs;

	struct writeback_control wbc = {

		.bdi		= NULL,

		.sync_mode	= WB_SYNC_NONE,
@@ -415,11 +398,11 @@ static void wb_kupdate(unsigned long arg) 


	sync_supers();



	get_writeback_state(&wbs);

	oldest_jif = jiffies - dirty_expire_interval;

	start_jif = jiffies;

	next_jif = start_jif + dirty_writeback_interval;

	nr_to_write = wbs.nr_dirty + wbs.nr_unstable +

	nr_to_write = global_page_state(NR_FILE_DIRTY) +

			global_page_state(NR_UNSTABLE_NFS) +

			(inodes_stat.nr_inodes - inodes_stat.nr_unused);

	while (nr_to_write > 0) {

		wbc.encountered_congestion = 0;