From a88a341a73be4ef035ca26170c849f002797da27 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 22 May 2015 17:13:28 -0400 Subject: writeback: move bandwidth related fields from backing_dev_info into bdi_writeback Currently, a bdi (backing_dev_info) embeds single wb (bdi_writeback) and the role of the separation is unclear. For cgroup support for writeback IOs, a bdi will be updated to host multiple wb's where each wb serves writeback IOs of a different cgroup on the bdi. To achieve that, a wb should carry all states necessary for servicing writeback IOs for a cgroup independently. This patch moves bandwidth related fields from backing_dev_info into bdi_writeback. * The moved fields are: bw_time_stamp, dirtied_stamp, written_stamp, write_bandwidth, avg_write_bandwidth, dirty_ratelimit, balanced_dirty_ratelimit, completions and dirty_exceeded. * writeback_chunk_size() and over_bground_thresh() now take @wb instead of @bdi. * bdi_writeout_fraction(bdi, ...) -> wb_writeout_fraction(wb, ...) bdi_dirty_limit(bdi, ...) -> wb_dirty_limit(wb, ...) bdi_position_ration(bdi, ...) -> wb_position_ratio(wb, ...) bdi_update_writebandwidth(bdi, ...) -> wb_update_write_bandwidth(wb, ...) [__]bdi_update_bandwidth(bdi, ...) -> [__]wb_update_bandwidth(wb, ...) bdi_{max|min}_pause(bdi, ...) -> wb_{max|min}_pause(wb, ...) bdi_dirty_limits(bdi, ...) -> wb_dirty_limits(wb, ...) * Init/exits of the relocated fields are moved to bdi_wb_init/exit() respectively. Note that explicit zeroing is dropped in the process as wb's are cleared in entirety anyway. * As there's still only one bdi_writeback per backing_dev_info, all uses of bdi->stat[] are mechanically replaced with bdi->wb.stat[] introducing no behavior changes. v2: Typo in description fixed as suggested by Jan. Signed-off-by: Tejun Heo Reviewed-by: Jan Kara Cc: Jens Axboe Cc: Wu Fengguang Cc: Jaegeuk Kim Cc: Steven Whitehouse Signed-off-by: Jens Axboe --- mm/page-writeback.c | 262 ++++++++++++++++++++++++++-------------------------- 1 file changed, 132 insertions(+), 130 deletions(-) (limited to 'mm/page-writeback.c') diff --git a/mm/page-writeback.c b/mm/page-writeback.c index dc673a035413..cd39ee91b7bb 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -399,7 +399,7 @@ static unsigned long wp_next_time(unsigned long cur_time) static inline void __wb_writeout_inc(struct bdi_writeback *wb) { __inc_wb_stat(wb, WB_WRITTEN); - __fprop_inc_percpu_max(&writeout_completions, &wb->bdi->completions, + __fprop_inc_percpu_max(&writeout_completions, &wb->completions, wb->bdi->max_prop_frac); /* First event after period switching was turned off? */ if (!unlikely(writeout_period_time)) { @@ -427,10 +427,10 @@ EXPORT_SYMBOL_GPL(wb_writeout_inc); /* * Obtain an accurate fraction of the BDI's portion. */ -static void bdi_writeout_fraction(struct backing_dev_info *bdi, - long *numerator, long *denominator) +static void wb_writeout_fraction(struct bdi_writeback *wb, + long *numerator, long *denominator) { - fprop_fraction_percpu(&writeout_completions, &bdi->completions, + fprop_fraction_percpu(&writeout_completions, &wb->completions, numerator, denominator); } @@ -516,11 +516,11 @@ static unsigned long hard_dirty_limit(unsigned long thresh) } /** - * bdi_dirty_limit - @bdi's share of dirty throttling threshold - * @bdi: the backing_dev_info to query + * wb_dirty_limit - @wb's share of dirty throttling threshold + * @wb: bdi_writeback to query * @dirty: global dirty limit in pages * - * Returns @bdi's dirty limit in pages. The term "dirty" in the context of + * Returns @wb's dirty limit in pages. The term "dirty" in the context of * dirty balancing includes all PG_dirty, PG_writeback and NFS unstable pages. * * Note that balance_dirty_pages() will only seriously take it as a hard limit @@ -528,34 +528,35 @@ static unsigned long hard_dirty_limit(unsigned long thresh) * control. For example, when the device is completely stalled due to some error * conditions, or when there are 1000 dd tasks writing to a slow 10MB/s USB key. * In the other normal situations, it acts more gently by throttling the tasks - * more (rather than completely block them) when the bdi dirty pages go high. + * more (rather than completely block them) when the wb dirty pages go high. * * It allocates high/low dirty limits to fast/slow devices, in order to prevent * - starving fast devices * - piling up dirty pages (that will take long time to sync) on slow devices * - * The bdi's share of dirty limit will be adapting to its throughput and + * The wb's share of dirty limit will be adapting to its throughput and * bounded by the bdi->min_ratio and/or bdi->max_ratio parameters, if set. */ -unsigned long bdi_dirty_limit(struct backing_dev_info *bdi, unsigned long dirty) +unsigned long wb_dirty_limit(struct bdi_writeback *wb, unsigned long dirty) { - u64 bdi_dirty; + struct backing_dev_info *bdi = wb->bdi; + u64 wb_dirty; long numerator, denominator; /* * Calculate this BDI's share of the dirty ratio. */ - bdi_writeout_fraction(bdi, &numerator, &denominator); + wb_writeout_fraction(wb, &numerator, &denominator); - bdi_dirty = (dirty * (100 - bdi_min_ratio)) / 100; - bdi_dirty *= numerator; - do_div(bdi_dirty, denominator); + wb_dirty = (dirty * (100 - bdi_min_ratio)) / 100; + wb_dirty *= numerator; + do_div(wb_dirty, denominator); - bdi_dirty += (dirty * bdi->min_ratio) / 100; - if (bdi_dirty > (dirty * bdi->max_ratio) / 100) - bdi_dirty = dirty * bdi->max_ratio / 100; + wb_dirty += (dirty * bdi->min_ratio) / 100; + if (wb_dirty > (dirty * bdi->max_ratio) / 100) + wb_dirty = dirty * bdi->max_ratio / 100; - return bdi_dirty; + return wb_dirty; } /* @@ -664,14 +665,14 @@ static long long pos_ratio_polynom(unsigned long setpoint, * card's bdi_dirty may rush to many times higher than bdi_setpoint. * - the bdi dirty thresh drops quickly due to change of JBOD workload */ -static unsigned long bdi_position_ratio(struct backing_dev_info *bdi, - unsigned long thresh, - unsigned long bg_thresh, - unsigned long dirty, - unsigned long bdi_thresh, - unsigned long bdi_dirty) +static unsigned long wb_position_ratio(struct bdi_writeback *wb, + unsigned long thresh, + unsigned long bg_thresh, + unsigned long dirty, + unsigned long bdi_thresh, + unsigned long bdi_dirty) { - unsigned long write_bw = bdi->avg_write_bandwidth; + unsigned long write_bw = wb->avg_write_bandwidth; unsigned long freerun = dirty_freerun_ceiling(thresh, bg_thresh); unsigned long limit = hard_dirty_limit(thresh); unsigned long x_intercept; @@ -702,12 +703,12 @@ static unsigned long bdi_position_ratio(struct backing_dev_info *bdi, * consume arbitrary amount of RAM because it is accounted in * NR_WRITEBACK_TEMP which is not involved in calculating "nr_dirty". * - * Here, in bdi_position_ratio(), we calculate pos_ratio based on + * Here, in wb_position_ratio(), we calculate pos_ratio based on * two values: bdi_dirty and bdi_thresh. Let's consider an example: * total amount of RAM is 16GB, bdi->max_ratio is equal to 1%, global * limits are set by default to 10% and 20% (background and throttle). * Then bdi_thresh is 1% of 20% of 16GB. This amounts to ~8K pages. - * bdi_dirty_limit(bdi, bg_thresh) is about ~4K pages. bdi_setpoint is + * wb_dirty_limit(wb, bg_thresh) is about ~4K pages. bdi_setpoint is * about ~6K pages (as the average of background and throttle bdi * limits). The 3rd order polynomial will provide positive feedback if * bdi_dirty is under bdi_setpoint and vice versa. @@ -717,7 +718,7 @@ static unsigned long bdi_position_ratio(struct backing_dev_info *bdi, * much earlier than global "freerun" is reached (~23MB vs. ~2.3GB * in the example above). */ - if (unlikely(bdi->capabilities & BDI_CAP_STRICTLIMIT)) { + if (unlikely(wb->bdi->capabilities & BDI_CAP_STRICTLIMIT)) { long long bdi_pos_ratio; unsigned long bdi_bg_thresh; @@ -842,13 +843,13 @@ static unsigned long bdi_position_ratio(struct backing_dev_info *bdi, return pos_ratio; } -static void bdi_update_write_bandwidth(struct backing_dev_info *bdi, - unsigned long elapsed, - unsigned long written) +static void wb_update_write_bandwidth(struct bdi_writeback *wb, + unsigned long elapsed, + unsigned long written) { const unsigned long period = roundup_pow_of_two(3 * HZ); - unsigned long avg = bdi->avg_write_bandwidth; - unsigned long old = bdi->write_bandwidth; + unsigned long avg = wb->avg_write_bandwidth; + unsigned long old = wb->write_bandwidth; u64 bw; /* @@ -861,14 +862,14 @@ static void bdi_update_write_bandwidth(struct backing_dev_info *bdi, * @written may have decreased due to account_page_redirty(). * Avoid underflowing @bw calculation. */ - bw = written - min(written, bdi->written_stamp); + bw = written - min(written, wb->written_stamp); bw *= HZ; if (unlikely(elapsed > period)) { do_div(bw, elapsed); avg = bw; goto out; } - bw += (u64)bdi->write_bandwidth * (period - elapsed); + bw += (u64)wb->write_bandwidth * (period - elapsed); bw >>= ilog2(period); /* @@ -881,8 +882,8 @@ static void bdi_update_write_bandwidth(struct backing_dev_info *bdi, avg += (old - avg) >> 3; out: - bdi->write_bandwidth = bw; - bdi->avg_write_bandwidth = avg; + wb->write_bandwidth = bw; + wb->avg_write_bandwidth = avg; } /* @@ -947,20 +948,20 @@ static void global_update_bandwidth(unsigned long thresh, * Normal bdi tasks will be curbed at or below it in long term. * Obviously it should be around (write_bw / N) when there are N dd tasks. */ -static void bdi_update_dirty_ratelimit(struct backing_dev_info *bdi, - unsigned long thresh, - unsigned long bg_thresh, - unsigned long dirty, - unsigned long bdi_thresh, - unsigned long bdi_dirty, - unsigned long dirtied, - unsigned long elapsed) +static void wb_update_dirty_ratelimit(struct bdi_writeback *wb, + unsigned long thresh, + unsigned long bg_thresh, + unsigned long dirty, + unsigned long bdi_thresh, + unsigned long bdi_dirty, + unsigned long dirtied, + unsigned long elapsed) { unsigned long freerun = dirty_freerun_ceiling(thresh, bg_thresh); unsigned long limit = hard_dirty_limit(thresh); unsigned long setpoint = (freerun + limit) / 2; - unsigned long write_bw = bdi->avg_write_bandwidth; - unsigned long dirty_ratelimit = bdi->dirty_ratelimit; + unsigned long write_bw = wb->avg_write_bandwidth; + unsigned long dirty_ratelimit = wb->dirty_ratelimit; unsigned long dirty_rate; unsigned long task_ratelimit; unsigned long balanced_dirty_ratelimit; @@ -972,10 +973,10 @@ static void bdi_update_dirty_ratelimit(struct backing_dev_info *bdi, * The dirty rate will match the writeout rate in long term, except * when dirty pages are truncated by userspace or re-dirtied by FS. */ - dirty_rate = (dirtied - bdi->dirtied_stamp) * HZ / elapsed; + dirty_rate = (dirtied - wb->dirtied_stamp) * HZ / elapsed; - pos_ratio = bdi_position_ratio(bdi, thresh, bg_thresh, dirty, - bdi_thresh, bdi_dirty); + pos_ratio = wb_position_ratio(wb, thresh, bg_thresh, dirty, + bdi_thresh, bdi_dirty); /* * task_ratelimit reflects each dd's dirty rate for the past 200ms. */ @@ -1059,31 +1060,31 @@ static void bdi_update_dirty_ratelimit(struct backing_dev_info *bdi, /* * For strictlimit case, calculations above were based on bdi counters - * and limits (starting from pos_ratio = bdi_position_ratio() and up to + * and limits (starting from pos_ratio = wb_position_ratio() and up to * balanced_dirty_ratelimit = task_ratelimit * write_bw / dirty_rate). * Hence, to calculate "step" properly, we have to use bdi_dirty as * "dirty" and bdi_setpoint as "setpoint". * * We rampup dirty_ratelimit forcibly if bdi_dirty is low because * it's possible that bdi_thresh is close to zero due to inactivity - * of backing device (see the implementation of bdi_dirty_limit()). + * of backing device (see the implementation of wb_dirty_limit()). */ - if (unlikely(bdi->capabilities & BDI_CAP_STRICTLIMIT)) { + if (unlikely(wb->bdi->capabilities & BDI_CAP_STRICTLIMIT)) { dirty = bdi_dirty; if (bdi_dirty < 8) setpoint = bdi_dirty + 1; else setpoint = (bdi_thresh + - bdi_dirty_limit(bdi, bg_thresh)) / 2; + wb_dirty_limit(wb, bg_thresh)) / 2; } if (dirty < setpoint) { - x = min3(bdi->balanced_dirty_ratelimit, + x = min3(wb->balanced_dirty_ratelimit, balanced_dirty_ratelimit, task_ratelimit); if (dirty_ratelimit < x) step = x - dirty_ratelimit; } else { - x = max3(bdi->balanced_dirty_ratelimit, + x = max3(wb->balanced_dirty_ratelimit, balanced_dirty_ratelimit, task_ratelimit); if (dirty_ratelimit > x) step = dirty_ratelimit - x; @@ -1105,22 +1106,22 @@ static void bdi_update_dirty_ratelimit(struct backing_dev_info *bdi, else dirty_ratelimit -= step; - bdi->dirty_ratelimit = max(dirty_ratelimit, 1UL); - bdi->balanced_dirty_ratelimit = balanced_dirty_ratelimit; + wb->dirty_ratelimit = max(dirty_ratelimit, 1UL); + wb->balanced_dirty_ratelimit = balanced_dirty_ratelimit; - trace_bdi_dirty_ratelimit(bdi, dirty_rate, task_ratelimit); + trace_bdi_dirty_ratelimit(wb->bdi, dirty_rate, task_ratelimit); } -void __bdi_update_bandwidth(struct backing_dev_info *bdi, - unsigned long thresh, - unsigned long bg_thresh, - unsigned long dirty, - unsigned long bdi_thresh, - unsigned long bdi_dirty, - unsigned long start_time) +void __wb_update_bandwidth(struct bdi_writeback *wb, + unsigned long thresh, + unsigned long bg_thresh, + unsigned long dirty, + unsigned long bdi_thresh, + unsigned long bdi_dirty, + unsigned long start_time) { unsigned long now = jiffies; - unsigned long elapsed = now - bdi->bw_time_stamp; + unsigned long elapsed = now - wb->bw_time_stamp; unsigned long dirtied; unsigned long written; @@ -1130,44 +1131,44 @@ void __bdi_update_bandwidth(struct backing_dev_info *bdi, if (elapsed < BANDWIDTH_INTERVAL) return; - dirtied = percpu_counter_read(&bdi->wb.stat[WB_DIRTIED]); - written = percpu_counter_read(&bdi->wb.stat[WB_WRITTEN]); + dirtied = percpu_counter_read(&wb->stat[WB_DIRTIED]); + written = percpu_counter_read(&wb->stat[WB_WRITTEN]); /* * Skip quiet periods when disk bandwidth is under-utilized. * (at least 1s idle time between two flusher runs) */ - if (elapsed > HZ && time_before(bdi->bw_time_stamp, start_time)) + if (elapsed > HZ && time_before(wb->bw_time_stamp, start_time)) goto snapshot; if (thresh) { global_update_bandwidth(thresh, dirty, now); - bdi_update_dirty_ratelimit(bdi, thresh, bg_thresh, dirty, - bdi_thresh, bdi_dirty, - dirtied, elapsed); + wb_update_dirty_ratelimit(wb, thresh, bg_thresh, dirty, + bdi_thresh, bdi_dirty, + dirtied, elapsed); } - bdi_update_write_bandwidth(bdi, elapsed, written); + wb_update_write_bandwidth(wb, elapsed, written); snapshot: - bdi->dirtied_stamp = dirtied; - bdi->written_stamp = written; - bdi->bw_time_stamp = now; + wb->dirtied_stamp = dirtied; + wb->written_stamp = written; + wb->bw_time_stamp = now; } -static void bdi_update_bandwidth(struct backing_dev_info *bdi, - unsigned long thresh, - unsigned long bg_thresh, - unsigned long dirty, - unsigned long bdi_thresh, - unsigned long bdi_dirty, - unsigned long start_time) +static void wb_update_bandwidth(struct bdi_writeback *wb, + unsigned long thresh, + unsigned long bg_thresh, + unsigned long dirty, + unsigned long bdi_thresh, + unsigned long bdi_dirty, + unsigned long start_time) { - if (time_is_after_eq_jiffies(bdi->bw_time_stamp + BANDWIDTH_INTERVAL)) + if (time_is_after_eq_jiffies(wb->bw_time_stamp + BANDWIDTH_INTERVAL)) return; - spin_lock(&bdi->wb.list_lock); - __bdi_update_bandwidth(bdi, thresh, bg_thresh, dirty, - bdi_thresh, bdi_dirty, start_time); - spin_unlock(&bdi->wb.list_lock); + spin_lock(&wb->list_lock); + __wb_update_bandwidth(wb, thresh, bg_thresh, dirty, + bdi_thresh, bdi_dirty, start_time); + spin_unlock(&wb->list_lock); } /* @@ -1187,10 +1188,10 @@ static unsigned long dirty_poll_interval(unsigned long dirty, return 1; } -static unsigned long bdi_max_pause(struct backing_dev_info *bdi, - unsigned long bdi_dirty) +static unsigned long wb_max_pause(struct bdi_writeback *wb, + unsigned long bdi_dirty) { - unsigned long bw = bdi->avg_write_bandwidth; + unsigned long bw = wb->avg_write_bandwidth; unsigned long t; /* @@ -1206,14 +1207,14 @@ static unsigned long bdi_max_pause(struct backing_dev_info *bdi, return min_t(unsigned long, t, MAX_PAUSE); } -static long bdi_min_pause(struct backing_dev_info *bdi, - long max_pause, - unsigned long task_ratelimit, - unsigned long dirty_ratelimit, - int *nr_dirtied_pause) +static long wb_min_pause(struct bdi_writeback *wb, + long max_pause, + unsigned long task_ratelimit, + unsigned long dirty_ratelimit, + int *nr_dirtied_pause) { - long hi = ilog2(bdi->avg_write_bandwidth); - long lo = ilog2(bdi->dirty_ratelimit); + long hi = ilog2(wb->avg_write_bandwidth); + long lo = ilog2(wb->dirty_ratelimit); long t; /* target pause */ long pause; /* estimated next pause */ int pages; /* target nr_dirtied_pause */ @@ -1281,14 +1282,13 @@ static long bdi_min_pause(struct backing_dev_info *bdi, return pages >= DIRTY_POLL_THRESH ? 1 + t / 2 : t; } -static inline void bdi_dirty_limits(struct backing_dev_info *bdi, - unsigned long dirty_thresh, - unsigned long background_thresh, - unsigned long *bdi_dirty, - unsigned long *bdi_thresh, - unsigned long *bdi_bg_thresh) +static inline void wb_dirty_limits(struct bdi_writeback *wb, + unsigned long dirty_thresh, + unsigned long background_thresh, + unsigned long *bdi_dirty, + unsigned long *bdi_thresh, + unsigned long *bdi_bg_thresh) { - struct bdi_writeback *wb = &bdi->wb; unsigned long wb_reclaimable; /* @@ -1301,10 +1301,10 @@ static inline void bdi_dirty_limits(struct backing_dev_info *bdi, * In this case we don't want to hard throttle the USB key * dirtiers for 100 seconds until bdi_dirty drops under * bdi_thresh. Instead the auxiliary bdi control line in - * bdi_position_ratio() will let the dirtier task progress + * wb_position_ratio() will let the dirtier task progress * at some rate <= (write_bw / 2) for bringing down bdi_dirty. */ - *bdi_thresh = bdi_dirty_limit(bdi, dirty_thresh); + *bdi_thresh = wb_dirty_limit(wb, dirty_thresh); if (bdi_bg_thresh) *bdi_bg_thresh = dirty_thresh ? div_u64((u64)*bdi_thresh * @@ -1354,6 +1354,7 @@ static void balance_dirty_pages(struct address_space *mapping, unsigned long dirty_ratelimit; unsigned long pos_ratio; struct backing_dev_info *bdi = inode_to_bdi(mapping->host); + struct bdi_writeback *wb = &bdi->wb; bool strictlimit = bdi->capabilities & BDI_CAP_STRICTLIMIT; unsigned long start_time = jiffies; @@ -1378,8 +1379,8 @@ static void balance_dirty_pages(struct address_space *mapping, global_dirty_limits(&background_thresh, &dirty_thresh); if (unlikely(strictlimit)) { - bdi_dirty_limits(bdi, dirty_thresh, background_thresh, - &bdi_dirty, &bdi_thresh, &bg_thresh); + wb_dirty_limits(wb, dirty_thresh, background_thresh, + &bdi_dirty, &bdi_thresh, &bg_thresh); dirty = bdi_dirty; thresh = bdi_thresh; @@ -1410,28 +1411,28 @@ static void balance_dirty_pages(struct address_space *mapping, bdi_start_background_writeback(bdi); if (!strictlimit) - bdi_dirty_limits(bdi, dirty_thresh, background_thresh, - &bdi_dirty, &bdi_thresh, NULL); + wb_dirty_limits(wb, dirty_thresh, background_thresh, + &bdi_dirty, &bdi_thresh, NULL); dirty_exceeded = (bdi_dirty > bdi_thresh) && ((nr_dirty > dirty_thresh) || strictlimit); - if (dirty_exceeded && !bdi->dirty_exceeded) - bdi->dirty_exceeded = 1; + if (dirty_exceeded && !wb->dirty_exceeded) + wb->dirty_exceeded = 1; - bdi_update_bandwidth(bdi, dirty_thresh, background_thresh, - nr_dirty, bdi_thresh, bdi_dirty, - start_time); + wb_update_bandwidth(wb, dirty_thresh, background_thresh, + nr_dirty, bdi_thresh, bdi_dirty, + start_time); - dirty_ratelimit = bdi->dirty_ratelimit; - pos_ratio = bdi_position_ratio(bdi, dirty_thresh, - background_thresh, nr_dirty, - bdi_thresh, bdi_dirty); + dirty_ratelimit = wb->dirty_ratelimit; + pos_ratio = wb_position_ratio(wb, dirty_thresh, + background_thresh, nr_dirty, + bdi_thresh, bdi_dirty); task_ratelimit = ((u64)dirty_ratelimit * pos_ratio) >> RATELIMIT_CALC_SHIFT; - max_pause = bdi_max_pause(bdi, bdi_dirty); - min_pause = bdi_min_pause(bdi, max_pause, - task_ratelimit, dirty_ratelimit, - &nr_dirtied_pause); + max_pause = wb_max_pause(wb, bdi_dirty); + min_pause = wb_min_pause(wb, max_pause, + task_ratelimit, dirty_ratelimit, + &nr_dirtied_pause); if (unlikely(task_ratelimit == 0)) { period = max_pause; @@ -1515,15 +1516,15 @@ pause: * more page. However bdi_dirty has accounting errors. So use * the larger and more IO friendly wb_stat_error. */ - if (bdi_dirty <= wb_stat_error(&bdi->wb)) + if (bdi_dirty <= wb_stat_error(wb)) break; if (fatal_signal_pending(current)) break; } - if (!dirty_exceeded && bdi->dirty_exceeded) - bdi->dirty_exceeded = 0; + if (!dirty_exceeded && wb->dirty_exceeded) + wb->dirty_exceeded = 0; if (writeback_in_progress(bdi)) return; @@ -1577,6 +1578,7 @@ DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0; void balance_dirty_pages_ratelimited(struct address_space *mapping) { struct backing_dev_info *bdi = inode_to_bdi(mapping->host); + struct bdi_writeback *wb = &bdi->wb; int ratelimit; int *p; @@ -1584,7 +1586,7 @@ void balance_dirty_pages_ratelimited(struct address_space *mapping) return; ratelimit = current->nr_dirtied_pause; - if (bdi->dirty_exceeded) + if (wb->dirty_exceeded) ratelimit = min(ratelimit, 32 >> (PAGE_SHIFT - 10)); preempt_disable(); -- cgit v1.2.3