Re: [PATCH 14/49] writeback: s/bdi/wb/ in mm/page-writeback.c

Jan Kara
2015-04-20T15:18:25Z

On Mon 06-04-15 15:58:03, Tejun Heo wrote:
> Writeback operations will now be per wb (bdi_writeback) instead of
> bdi. Replace the relevant bdi references in symbol names and comments
> with wb. This patch is purely cosmetic and doesn't make any
> functional changes.
It's good you made things consistent. You can add:
Reviewed-by: Jan Kara <jack@suse.cz>

Honza

>
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Cc: Wu Fengguang <fengguang.wu@intel.com>
> Cc: Jan Kara <jack@suse.cz>
> Cc: Jens Axboe <axboe@kernel.dk>
> ---
> mm/page-writeback.c | 270 ++++++++++++++++++++++++++--------------------------
> 1 file changed, 134 insertions(+), 136 deletions(-)
>
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index 29fb4f3..c615a15 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -595,7 +595,7 @@ static long long pos_ratio_polynom(unsigned long setpoint,
> *
> * (o) global/bdi setpoints
> *
> - * We want the dirty pages be balanced around the global/bdi setpoints.
> + * We want the dirty pages be balanced around the global/wb setpoints.
> * When the number of dirty pages is higher/lower than the setpoint, the
> * dirty position control ratio (and hence task dirty ratelimit) will be
> * decreased/increased to bring the dirty pages back to the setpoint.
> @@ -605,8 +605,8 @@ static long long pos_ratio_polynom(unsigned long setpoint,
> * if (dirty < setpoint) scale up pos_ratio
> * if (dirty > setpoint) scale down pos_ratio
> *
> - * if (bdi_dirty < bdi_setpoint) scale up pos_ratio
> - * if (bdi_dirty > bdi_setpoint) scale down pos_ratio
> + * if (wb_dirty < wb_setpoint) scale up pos_ratio
> + * if (wb_dirty > wb_setpoint) scale down pos_ratio
> *
> * task_ratelimit = dirty_ratelimit * pos_ratio >> RATELIMIT_CALC_SHIFT
> *
> @@ -631,7 +631,7 @@ static long long pos_ratio_polynom(unsigned long setpoint,
> * 0 +------------.------------------.----------------------*------------->
> * freerun^ setpoint^ limit^ dirty pages
> *
> - * (o) bdi control line
> + * (o) wb control line
> *
> * ^ pos_ratio
> * |
> @@ -657,27 +657,27 @@ static long long pos_ratio_polynom(unsigned long setpoint,
> * | . .
> * | . .
> * 0 +----------------------.-------------------------------.------------->
> - * bdi_setpoint^ x_intercept^
> + * wb_setpoint^ x_intercept^
> *
> - * The bdi control line won't drop below pos_ratio=1/4, so that bdi_dirty can
> + * The wb control line won't drop below pos_ratio=1/4, so that wb_dirty can
> * be smoothly throttled down to normal if it starts high in situations like
> * - start writing to a slow SD card and a fast disk at the same time. The SD
> - * 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
> + * card's wb_dirty may rush to many times higher than wb_setpoint.
> + * - the wb dirty thresh drops quickly due to change of JBOD workload
> */
> 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 wb_thresh,
> + unsigned long wb_dirty)
> {
> 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;
> unsigned long setpoint; /* dirty pages' target balance point */
> - unsigned long bdi_setpoint;
> + unsigned long wb_setpoint;
> unsigned long span;
> long long pos_ratio; /* for scaling up/down the rate limit */
> long x;
> @@ -696,146 +696,145 @@ static unsigned long wb_position_ratio(struct bdi_writeback *wb,
> /*
> * The strictlimit feature is a tool preventing mistrusted filesystems
> * from growing a large number of dirty pages before throttling. For
> - * such filesystems balance_dirty_pages always checks bdi counters
> - * against bdi limits. Even if global "nr_dirty" is under "freerun".
> + * such filesystems balance_dirty_pages always checks wb counters
> + * against wb limits. Even if global "nr_dirty" is under "freerun".
> * This is especially important for fuse which sets bdi->max_ratio to
> * 1% by default. Without strictlimit feature, fuse writeback may
> * consume arbitrary amount of RAM because it is accounted in
> * NR_WRITEBACK_TEMP which is not involved in calculating "nr_dirty".
> *
> * Here, in wb_position_ratio(), we calculate pos_ratio based on
> - * two values: bdi_dirty and bdi_thresh. Let's consider an example:
> + * two values: wb_dirty and wb_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.
> - * wb_dirty_limit(wb, bg_thresh) is about ~4K pages. bdi_setpoint is
> - * about ~6K pages (as the average of background and throttle bdi
> + * Then wb_thresh is 1% of 20% of 16GB. This amounts to ~8K pages.
> + * wb_dirty_limit(wb, bg_thresh) is about ~4K pages. wb_setpoint is
> + * about ~6K pages (as the average of background and throttle wb
> * limits). The 3rd order polynomial will provide positive feedback if
> - * bdi_dirty is under bdi_setpoint and vice versa.
> + * wb_dirty is under wb_setpoint and vice versa.
> *
> * Note, that we cannot use global counters in these calculations
> - * because we want to throttle process writing to a strictlimit BDI
> + * because we want to throttle process writing to a strictlimit wb
> * much earlier than global "freerun" is reached (~23MB vs. ~2.3GB
> * in the example above).
> */
> if (unlikely(wb->bdi->capabilities & BDI_CAP_STRICTLIMIT)) {
> - long long bdi_pos_ratio;
> - unsigned long bdi_bg_thresh;
> + long long wb_pos_ratio;
> + unsigned long wb_bg_thresh;
>
> - if (bdi_dirty < 8)
> + if (wb_dirty < 8)
> return min_t(long long, pos_ratio * 2,
> 2 << RATELIMIT_CALC_SHIFT);
>
> - if (bdi_dirty >= bdi_thresh)
> + if (wb_dirty >= wb_thresh)
> return 0;
>
> - bdi_bg_thresh = div_u64((u64)bdi_thresh * bg_thresh, thresh);
> - bdi_setpoint = dirty_freerun_ceiling(bdi_thresh,
> - bdi_bg_thresh);
> + wb_bg_thresh = div_u64((u64)wb_thresh * bg_thresh, thresh);
> + wb_setpoint = dirty_freerun_ceiling(wb_thresh, wb_bg_thresh);
>
> - if (bdi_setpoint == 0 || bdi_setpoint == bdi_thresh)
> + if (wb_setpoint == 0 || wb_setpoint == wb_thresh)
> return 0;
>
> - bdi_pos_ratio = pos_ratio_polynom(bdi_setpoint, bdi_dirty,
> - bdi_thresh);
> + wb_pos_ratio = pos_ratio_polynom(wb_setpoint, wb_dirty,
> + wb_thresh);
>
> /*
> - * Typically, for strictlimit case, bdi_setpoint << setpoint
> - * and pos_ratio >> bdi_pos_ratio. In the other words global
> + * Typically, for strictlimit case, wb_setpoint << setpoint
> + * and pos_ratio >> wb_pos_ratio. In the other words global
> * state ("dirty") is not limiting factor and we have to
> - * make decision based on bdi counters. But there is an
> + * make decision based on wb counters. But there is an
> * important case when global pos_ratio should get precedence:
> * global limits are exceeded (e.g. due to activities on other
> - * BDIs) while given strictlimit BDI is below limit.
> + * wb's) while given strictlimit wb is below limit.
> *
> - * "pos_ratio * bdi_pos_ratio" would work for the case above,
> + * "pos_ratio * wb_pos_ratio" would work for the case above,
> * but it would look too non-natural for the case of all
> - * activity in the system coming from a single strictlimit BDI
> + * activity in the system coming from a single strictlimit wb
> * with bdi->max_ratio == 100%.
> *
> * Note that min() below somewhat changes the dynamics of the
> * control system. Normally, pos_ratio value can be well over 3
> - * (when globally we are at freerun and bdi is well below bdi
> + * (when globally we are at freerun and wb is well below wb
> * setpoint). Now the maximum pos_ratio in the same situation
> * is 2. We might want to tweak this if we observe the control
> * system is too slow to adapt.
> */
> - return min(pos_ratio, bdi_pos_ratio);
> + return min(pos_ratio, wb_pos_ratio);
> }
>
> /*
> * We have computed basic pos_ratio above based on global situation. If
> - * the bdi is over/under its share of dirty pages, we want to scale
> + * the wb is over/under its share of dirty pages, we want to scale
> * pos_ratio further down/up. That is done by the following mechanism.
> */
>
> /*
> - * bdi setpoint
> + * wb setpoint
> *
> - * f(bdi_dirty) := 1.0 + k * (bdi_dirty - bdi_setpoint)
> + * f(wb_dirty) := 1.0 + k * (wb_dirty - wb_setpoint)
> *
> - * x_intercept - bdi_dirty
> + * x_intercept - wb_dirty
> * := --------------------------
> - * x_intercept - bdi_setpoint
> + * x_intercept - wb_setpoint
> *
> - * The main bdi control line is a linear function that subjects to
> + * The main wb control line is a linear function that subjects to
> *
> - * (1) f(bdi_setpoint) = 1.0
> - * (2) k = - 1 / (8 * write_bw) (in single bdi case)
> - * or equally: x_intercept = bdi_setpoint + 8 * write_bw
> + * (1) f(wb_setpoint) = 1.0
> + * (2) k = - 1 / (8 * write_bw) (in single wb case)
> + * or equally: x_intercept = wb_setpoint + 8 * write_bw
> *
> - * For single bdi case, the dirty pages are observed to fluctuate
> + * For single wb case, the dirty pages are observed to fluctuate
> * regularly within range
> - * [bdi_setpoint - write_bw/2, bdi_setpoint + write_bw/2]
> + * [wb_setpoint - write_bw/2, wb_setpoint + write_bw/2]
> * for various filesystems, where (2) can yield in a reasonable 12.5%
> * fluctuation range for pos_ratio.
> *
> - * For JBOD case, bdi_thresh (not bdi_dirty!) could fluctuate up to its
> + * For JBOD case, wb_thresh (not wb_dirty!) could fluctuate up to its
> * own size, so move the slope over accordingly and choose a slope that
> - * yields 100% pos_ratio fluctuation on suddenly doubled bdi_thresh.
> + * yields 100% pos_ratio fluctuation on suddenly doubled wb_thresh.
> */
> - if (unlikely(bdi_thresh > thresh))
> - bdi_thresh = thresh;
> + if (unlikely(wb_thresh > thresh))
> + wb_thresh = thresh;
> /*
> - * It's very possible that bdi_thresh is close to 0 not because the
> + * It's very possible that wb_thresh is close to 0 not because the
> * device is slow, but that it has remained inactive for long time.
> * Honour such devices a reasonable good (hopefully IO efficient)
> * threshold, so that the occasional writes won't be blocked and active
> * writes can rampup the threshold quickly.
> */
> - bdi_thresh = max(bdi_thresh, (limit - dirty) / 8);
> + wb_thresh = max(wb_thresh, (limit - dirty) / 8);
> /*
> - * scale global setpoint to bdi's:
> - * bdi_setpoint = setpoint * bdi_thresh / thresh
> + * scale global setpoint to wb's:
> + * wb_setpoint = setpoint * wb_thresh / thresh
> */
> - x = div_u64((u64)bdi_thresh << 16, thresh + 1);
> - bdi_setpoint = setpoint * (u64)x >> 16;
> + x = div_u64((u64)wb_thresh << 16, thresh + 1);
> + wb_setpoint = setpoint * (u64)x >> 16;
> /*
> - * Use span=(8*write_bw) in single bdi case as indicated by
> - * (thresh - bdi_thresh ~= 0) and transit to bdi_thresh in JBOD case.
> + * Use span=(8*write_bw) in single wb case as indicated by
> + * (thresh - wb_thresh ~= 0) and transit to wb_thresh in JBOD case.
> *
> - * bdi_thresh thresh - bdi_thresh
> - * span = ---------- * (8 * write_bw) + ------------------- * bdi_thresh
> - * thresh thresh
> + * wb_thresh thresh - wb_thresh
> + * span = --------- * (8 * write_bw) + ------------------ * wb_thresh
> + * thresh thresh
> */
> - span = (thresh - bdi_thresh + 8 * write_bw) * (u64)x >> 16;
> - x_intercept = bdi_setpoint + span;
> + span = (thresh - wb_thresh + 8 * write_bw) * (u64)x >> 16;
> + x_intercept = wb_setpoint + span;
>
> - if (bdi_dirty < x_intercept - span / 4) {
> - pos_ratio = div64_u64(pos_ratio * (x_intercept - bdi_dirty),
> - x_intercept - bdi_setpoint + 1);
> + if (wb_dirty < x_intercept - span / 4) {
> + pos_ratio = div64_u64(pos_ratio * (x_intercept - wb_dirty),
> + x_intercept - wb_setpoint + 1);
> } else
> pos_ratio /= 4;
>
> /*
> - * bdi reserve area, safeguard against dirty pool underrun and disk idle
> + * wb reserve area, safeguard against dirty pool underrun and disk idle
> * It may push the desired control point of global dirty pages higher
> * than setpoint.
> */
> - x_intercept = bdi_thresh / 2;
> - if (bdi_dirty < x_intercept) {
> - if (bdi_dirty > x_intercept / 8)
> - pos_ratio = div_u64(pos_ratio * x_intercept, bdi_dirty);
> + x_intercept = wb_thresh / 2;
> + if (wb_dirty < x_intercept) {
> + if (wb_dirty > x_intercept / 8)
> + pos_ratio = div_u64(pos_ratio * x_intercept, wb_dirty);
> else
> pos_ratio *= 8;
> }
> @@ -943,17 +942,17 @@ static void global_update_bandwidth(unsigned long thresh,
> }
>
> /*
> - * Maintain bdi->dirty_ratelimit, the base dirty throttle rate.
> + * Maintain wb->dirty_ratelimit, the base dirty throttle rate.
> *
> - * Normal bdi tasks will be curbed at or below it in long term.
> + * Normal wb 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 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 wb_thresh,
> + unsigned long wb_dirty,
> unsigned long dirtied,
> unsigned long elapsed)
> {
> @@ -976,7 +975,7 @@ static void wb_update_dirty_ratelimit(struct bdi_writeback *wb,
> dirty_rate = (dirtied - wb->dirtied_stamp) * HZ / elapsed;
>
> pos_ratio = wb_position_ratio(wb, thresh, bg_thresh, dirty,
> - bdi_thresh, bdi_dirty);
> + wb_thresh, wb_dirty);
> /*
> * task_ratelimit reflects each dd's dirty rate for the past 200ms.
> */
> @@ -986,7 +985,7 @@ static void wb_update_dirty_ratelimit(struct bdi_writeback *wb,
>
> /*
> * A linear estimation of the "balanced" throttle rate. The theory is,
> - * if there are N dd tasks, each throttled at task_ratelimit, the bdi's
> + * if there are N dd tasks, each throttled at task_ratelimit, the wb's
> * dirty_rate will be measured to be (N * task_ratelimit). So the below
> * formula will yield the balanced rate limit (write_bw / N).
> *
> @@ -1025,7 +1024,7 @@ static void wb_update_dirty_ratelimit(struct bdi_writeback *wb,
> /*
> * We could safely do this and return immediately:
> *
> - * bdi->dirty_ratelimit = balanced_dirty_ratelimit;
> + * wb->dirty_ratelimit = balanced_dirty_ratelimit;
> *
> * However to get a more stable dirty_ratelimit, the below elaborated
> * code makes use of task_ratelimit to filter out singular points and
> @@ -1059,22 +1058,22 @@ static void wb_update_dirty_ratelimit(struct bdi_writeback *wb,
> step = 0;
>
> /*
> - * For strictlimit case, calculations above were based on bdi counters
> + * For strictlimit case, calculations above were based on wb counters
> * 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".
> + * Hence, to calculate "step" properly, we have to use wb_dirty as
> + * "dirty" and wb_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
> + * 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_dirty_limit()).
> */
> if (unlikely(wb->bdi->capabilities & BDI_CAP_STRICTLIMIT)) {
> - dirty = bdi_dirty;
> - if (bdi_dirty < 8)
> - setpoint = bdi_dirty + 1;
> + dirty = wb_dirty;
> + if (wb_dirty < 8)
> + setpoint = wb_dirty + 1;
> else
> - setpoint = (bdi_thresh +
> + setpoint = (wb_thresh +
> wb_dirty_limit(wb, bg_thresh)) / 2;
> }
>
> @@ -1116,8 +1115,8 @@ 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 wb_thresh,
> + unsigned long wb_dirty,
> unsigned long start_time)
> {
> unsigned long now = jiffies;
> @@ -1144,7 +1143,7 @@ void __wb_update_bandwidth(struct bdi_writeback *wb,
> if (thresh) {
> global_update_bandwidth(thresh, dirty, now);
> wb_update_dirty_ratelimit(wb, thresh, bg_thresh, dirty,
> - bdi_thresh, bdi_dirty,
> + wb_thresh, wb_dirty,
> dirtied, elapsed);
> }
> wb_update_write_bandwidth(wb, elapsed, written);
> @@ -1159,15 +1158,15 @@ 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 wb_thresh,
> + unsigned long wb_dirty,
> unsigned long start_time)
> {
> if (time_is_after_eq_jiffies(wb->bw_time_stamp + BANDWIDTH_INTERVAL))
> return;
> spin_lock(&wb->list_lock);
> __wb_update_bandwidth(wb, thresh, bg_thresh, dirty,
> - bdi_thresh, bdi_dirty, start_time);
> + wb_thresh, wb_dirty, start_time);
> spin_unlock(&wb->list_lock);
> }
>
> @@ -1189,7 +1188,7 @@ static unsigned long dirty_poll_interval(unsigned long dirty,
> }
>
> static unsigned long wb_max_pause(struct bdi_writeback *wb,
> - unsigned long bdi_dirty)
> + unsigned long wb_dirty)
> {
> unsigned long bw = wb->avg_write_bandwidth;
> unsigned long t;
> @@ -1201,7 +1200,7 @@ static unsigned long wb_max_pause(struct bdi_writeback *wb,
> *
> * 8 serves as the safety ratio.
> */
> - t = bdi_dirty / (1 + bw / roundup_pow_of_two(1 + HZ / 8));
> + t = wb_dirty / (1 + bw / roundup_pow_of_two(1 + HZ / 8));
> t++;
>
> return min_t(unsigned long, t, MAX_PAUSE);
> @@ -1285,31 +1284,31 @@ static long wb_min_pause(struct bdi_writeback *wb,
> 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)
> + unsigned long *wb_dirty,
> + unsigned long *wb_thresh,
> + unsigned long *wb_bg_thresh)
> {
> unsigned long wb_reclaimable;
>
> /*
> - * bdi_thresh is not treated as some limiting factor as
> + * wb_thresh is not treated as some limiting factor as
> * dirty_thresh, due to reasons
> - * - in JBOD setup, bdi_thresh can fluctuate a lot
> + * - in JBOD setup, wb_thresh can fluctuate a lot
> * - in a system with HDD and USB key, the USB key may somehow
> - * go into state (bdi_dirty >> bdi_thresh) either because
> - * bdi_dirty starts high, or because bdi_thresh drops low.
> + * go into state (wb_dirty >> wb_thresh) either because
> + * wb_dirty starts high, or because wb_thresh drops low.
> * 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
> + * dirtiers for 100 seconds until wb_dirty drops under
> + * wb_thresh. Instead the auxiliary wb control line in
> * wb_position_ratio() will let the dirtier task progress
> - * at some rate <= (write_bw / 2) for bringing down bdi_dirty.
> + * at some rate <= (write_bw / 2) for bringing down wb_dirty.
> */
> - *bdi_thresh = wb_dirty_limit(wb, dirty_thresh);
> + *wb_thresh = wb_dirty_limit(wb, dirty_thresh);
>
> - if (bdi_bg_thresh)
> - *bdi_bg_thresh = dirty_thresh ? div_u64((u64)*bdi_thresh *
> - background_thresh,
> - dirty_thresh) : 0;
> + if (wb_bg_thresh)
> + *wb_bg_thresh = dirty_thresh ? div_u64((u64)*wb_thresh *
> + background_thresh,
> + dirty_thresh) : 0;
>
> /*
> * In order to avoid the stacked BDI deadlock we need
> @@ -1321,12 +1320,12 @@ static inline void wb_dirty_limits(struct bdi_writeback *wb,
> * actually dirty; with m+n sitting in the percpu
> * deltas.
> */
> - if (*bdi_thresh < 2 * wb_stat_error(wb)) {
> + if (*wb_thresh < 2 * wb_stat_error(wb)) {
> wb_reclaimable = wb_stat_sum(wb, WB_RECLAIMABLE);
> - *bdi_dirty = wb_reclaimable + wb_stat_sum(wb, WB_WRITEBACK);
> + *wb_dirty = wb_reclaimable + wb_stat_sum(wb, WB_WRITEBACK);
> } else {
> wb_reclaimable = wb_stat(wb, WB_RECLAIMABLE);
> - *bdi_dirty = wb_reclaimable + wb_stat(wb, WB_WRITEBACK);
> + *wb_dirty = wb_reclaimable + wb_stat(wb, WB_WRITEBACK);
> }
> }
>
> @@ -1360,9 +1359,9 @@ static void balance_dirty_pages(struct address_space *mapping,
>
> for (;;) {
> unsigned long now = jiffies;
> - unsigned long uninitialized_var(bdi_thresh);
> + unsigned long uninitialized_var(wb_thresh);
> unsigned long thresh;
> - unsigned long uninitialized_var(bdi_dirty);
> + unsigned long uninitialized_var(wb_dirty);
> unsigned long dirty;
> unsigned long bg_thresh;
>
> @@ -1380,10 +1379,10 @@ static void balance_dirty_pages(struct address_space *mapping,
>
> if (unlikely(strictlimit)) {
> wb_dirty_limits(wb, dirty_thresh, background_thresh,
> - &bdi_dirty, &bdi_thresh, &bg_thresh);
> + &wb_dirty, &wb_thresh, &bg_thresh);
>
> - dirty = bdi_dirty;
> - thresh = bdi_thresh;
> + dirty = wb_dirty;
> + thresh = wb_thresh;
> } else {
> dirty = nr_dirty;
> thresh = dirty_thresh;
> @@ -1393,10 +1392,10 @@ static void balance_dirty_pages(struct address_space *mapping,
> /*
> * Throttle it only when the background writeback cannot
> * catch-up. This avoids (excessively) small writeouts
> - * when the bdi limits are ramping up in case of !strictlimit.
> + * when the wb limits are ramping up in case of !strictlimit.
> *
> - * In strictlimit case make decision based on the bdi counters
> - * and limits. Small writeouts when the bdi limits are ramping
> + * In strictlimit case make decision based on the wb counters
> + * and limits. Small writeouts when the wb limits are ramping
> * up are the price we consciously pay for strictlimit-ing.
> */
> if (dirty <= dirty_freerun_ceiling(thresh, bg_thresh)) {
> @@ -1412,24 +1411,23 @@ static void balance_dirty_pages(struct address_space *mapping,
>
> if (!strictlimit)
> wb_dirty_limits(wb, dirty_thresh, background_thresh,
> - &bdi_dirty, &bdi_thresh, NULL);
> + &wb_dirty, &wb_thresh, NULL);
>
> - dirty_exceeded = (bdi_dirty > bdi_thresh) &&
> + dirty_exceeded = (wb_dirty > wb_thresh) &&
> ((nr_dirty > dirty_thresh) || strictlimit);
> if (dirty_exceeded && !wb->dirty_exceeded)
> wb->dirty_exceeded = 1;
>
> wb_update_bandwidth(wb, dirty_thresh, background_thresh,
> - nr_dirty, bdi_thresh, bdi_dirty,
> - start_time);
> + nr_dirty, wb_thresh, wb_dirty, start_time);
>
> dirty_ratelimit = wb->dirty_ratelimit;
> pos_ratio = wb_position_ratio(wb, dirty_thresh,
> background_thresh, nr_dirty,
> - bdi_thresh, bdi_dirty);
> + wb_thresh, wb_dirty);
> task_ratelimit = ((u64)dirty_ratelimit * pos_ratio) >>
> RATELIMIT_CALC_SHIFT;
> - max_pause = wb_max_pause(wb, bdi_dirty);
> + max_pause = wb_max_pause(wb, wb_dirty);
> min_pause = wb_min_pause(wb, max_pause,
> task_ratelimit, dirty_ratelimit,
> &nr_dirtied_pause);
> @@ -1455,8 +1453,8 @@ static void balance_dirty_pages(struct address_space *mapping,
> dirty_thresh,
> background_thresh,
> nr_dirty,
> - bdi_thresh,
> - bdi_dirty,
> + wb_thresh,
> + wb_dirty,
> dirty_ratelimit,
> task_ratelimit,
> pages_dirtied,
> @@ -1484,8 +1482,8 @@ pause:
> dirty_thresh,
> background_thresh,
> nr_dirty,
> - bdi_thresh,
> - bdi_dirty,
> + wb_thresh,
> + wb_dirty,
> dirty_ratelimit,
> task_ratelimit,
> pages_dirtied,
> @@ -1508,15 +1506,15 @@ pause:
>
> /*
> * In the case of an unresponding NFS server and the NFS dirty
> - * pages exceeds dirty_thresh, give the other good bdi's a pipe
> + * pages exceeds dirty_thresh, give the other good wb's a pipe
> * to go through, so that tasks on them still remain responsive.
> *
> * In theory 1 page is enough to keep the comsumer-producer
> * pipe going: the flusher cleans 1 page => the task dirties 1
> - * more page. However bdi_dirty has accounting errors. So use
> + * more page. However wb_dirty has accounting errors. So use
> * the larger and more IO friendly wb_stat_error.
> */
> - if (bdi_dirty <= wb_stat_error(wb))
> + if (wb_dirty <= wb_stat_error(wb))
> break;
>
> if (fatal_signal_pending(current))
> --
> 2.1.0
>
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR