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[PATCH] zoned vm counters: remove useless struct wbs
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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: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Christoph Lameter authored and Linus Torvalds committed Jun 30, 2006
1 parent d2c5e30 commit c24f21b
Showing 1 changed file with 34 additions and 51 deletions.
85 changes: 34 additions & 51 deletions mm/page-writeback.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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.
Expand All @@ -134,8 +117,8 @@ static void get_writeback_state(struct writeback_state *wbs)
* clamping level.
*/
static void
get_dirty_limits(struct writeback_state *wbs, long *pbackground, long *pdirty,
struct address_space *mapping)
get_dirty_limits(long *pbackground, long *pdirty,
struct address_space *mapping)
{
int background_ratio; /* Percentages */
int dirty_ratio;
Expand All @@ -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,
Expand All @@ -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)
Expand Down Expand Up @@ -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;
Expand All @@ -208,11 +190,12 @@ 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)
break;
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)
dirty_exceeded = 1;
Expand All @@ -225,20 +208,24 @@ static void balance_dirty_pages(struct address_space *mapping)
*/
if (nr_reclaimable) {
writeback_inodes(&wbc);
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)
break;
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;
pages_written += write_chunk - wbc.nr_to_write;
if (pages_written >= write_chunk)
break; /* We've done our duty */
}
blk_congestion_wait(WRITE, HZ/10);
}

if (nr_reclaimable + wbs.nr_writeback <= dirty_thresh && dirty_exceeded)
dirty_exceeded = 0;
if (nr_reclaimable + global_page_state(NR_WRITEBACK)
<= dirty_thresh && dirty_exceeded)
dirty_exceeded = 0;

if (writeback_in_progress(bdi))
return; /* pdflush is already working this queue */
Expand Down Expand Up @@ -300,21 +287,21 @@ 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
* allocators so they don't get DoS'ed by heavy writers
*/
dirty_thresh += dirty_thresh / 10; /* wheeee... */

if (wbs.nr_unstable + wbs.nr_writeback <= dirty_thresh)
break;
if (global_page_state(NR_UNSTABLE_NFS) +
global_page_state(NR_WRITEBACK) <= dirty_thresh)
break;
blk_congestion_wait(WRITE, HZ/10);
}
}
Expand All @@ -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;
Expand All @@ -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);
}

Expand Down Expand Up @@ -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,
Expand All @@ -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;
Expand Down

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