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-rw-r--r--mm/page-writeback.c27
1 files changed, 11 insertions, 16 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 126e3c8bc1c6..3ec922309178 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -134,6 +134,7 @@ struct dirty_throttle_control {
unsigned long wb_dirty; /* per-wb counterparts */
unsigned long wb_thresh;
+ unsigned long wb_bg_thresh;
};
#define GDTC_INIT(__wb) .wb = (__wb)
@@ -761,7 +762,6 @@ static unsigned long wb_position_ratio(struct dirty_throttle_control *dtc)
*/
if (unlikely(wb->bdi->capabilities & BDI_CAP_STRICTLIMIT)) {
long long wb_pos_ratio;
- unsigned long wb_bg_thresh;
if (dtc->wb_dirty < 8)
return min_t(long long, pos_ratio * 2,
@@ -770,9 +770,8 @@ static unsigned long wb_position_ratio(struct dirty_throttle_control *dtc)
if (dtc->wb_dirty >= wb_thresh)
return 0;
- wb_bg_thresh = div_u64((u64)wb_thresh * dtc->bg_thresh,
- dtc->thresh);
- wb_setpoint = dirty_freerun_ceiling(wb_thresh, wb_bg_thresh);
+ wb_setpoint = dirty_freerun_ceiling(wb_thresh,
+ dtc->wb_bg_thresh);
if (wb_setpoint == 0 || wb_setpoint == wb_thresh)
return 0;
@@ -1104,15 +1103,14 @@ static void wb_update_dirty_ratelimit(struct dirty_throttle_control *dtc,
*
* We rampup dirty_ratelimit forcibly if wb_dirty is low because
* it's possible that wb_thresh is close to zero due to inactivity
- * of backing device (see the implementation of wb_calc_thresh()).
+ * of backing device.
*/
if (unlikely(wb->bdi->capabilities & BDI_CAP_STRICTLIMIT)) {
dirty = dtc->wb_dirty;
if (dtc->wb_dirty < 8)
setpoint = dtc->wb_dirty + 1;
else
- setpoint = (dtc->wb_thresh +
- wb_calc_thresh(wb, dtc->bg_thresh)) / 2;
+ setpoint = (dtc->wb_thresh + dtc->wb_bg_thresh) / 2;
}
if (dirty < setpoint) {
@@ -1307,8 +1305,7 @@ static long wb_min_pause(struct bdi_writeback *wb,
return pages >= DIRTY_POLL_THRESH ? 1 + t / 2 : t;
}
-static inline void wb_dirty_limits(struct dirty_throttle_control *dtc,
- unsigned long *wb_bg_thresh)
+static inline void wb_dirty_limits(struct dirty_throttle_control *dtc)
{
struct bdi_writeback *wb = dtc->wb;
unsigned long wb_reclaimable;
@@ -1327,11 +1324,8 @@ static inline void wb_dirty_limits(struct dirty_throttle_control *dtc,
* at some rate <= (write_bw / 2) for bringing down wb_dirty.
*/
dtc->wb_thresh = wb_calc_thresh(dtc->wb, dtc->thresh);
-
- if (wb_bg_thresh)
- *wb_bg_thresh = dtc->thresh ? div_u64((u64)dtc->wb_thresh *
- dtc->bg_thresh,
- dtc->thresh) : 0;
+ dtc->wb_bg_thresh = dtc->thresh ?
+ div_u64((u64)dtc->wb_thresh * dtc->bg_thresh, dtc->thresh) : 0;
/*
* In order to avoid the stacked BDI deadlock we need
@@ -1396,10 +1390,11 @@ static void balance_dirty_pages(struct address_space *mapping,
global_dirty_limits(&gdtc->bg_thresh, &gdtc->thresh);
if (unlikely(strictlimit)) {
- wb_dirty_limits(gdtc, &bg_thresh);
+ wb_dirty_limits(gdtc);
dirty = gdtc->wb_dirty;
thresh = gdtc->wb_thresh;
+ bg_thresh = gdtc->wb_bg_thresh;
} else {
dirty = gdtc->dirty;
thresh = gdtc->thresh;
@@ -1427,7 +1422,7 @@ static void balance_dirty_pages(struct address_space *mapping,
wb_start_background_writeback(wb);
if (!strictlimit)
- wb_dirty_limits(gdtc, NULL);
+ wb_dirty_limits(gdtc);
dirty_exceeded = (gdtc->wb_dirty > gdtc->wb_thresh) &&
((gdtc->dirty > gdtc->thresh) || strictlimit);