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authorTejun Heo <tj@kernel.org>2015-05-22 17:13:27 -0400
committerJens Axboe <axboe@fb.com>2015-06-02 08:33:34 -0600
commit93f78d882865cb90020d0f80a9523c99cf46924c (patch)
tree6cd9c3531085c7d51fbd6ec2086142255bc2c219 /include/linux/backing-dev.h
parent4452226ea276e74fc3e252c88d9bb7e8f8e44bf0 (diff)
writeback: move backing_dev_info->bdi_stat[] 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 bdi->bdi_stat[] into wb. * enum bdi_stat_item is renamed to wb_stat_item and the prefix of all enums is changed from BDI_ to WB_. * BDI_STAT_BATCH() -> WB_STAT_BATCH() * [__]{add|inc|dec|sum}_wb_stat(bdi, ...) -> [__]{add|inc}_wb_stat(wb, ...) * bdi_stat[_error]() -> wb_stat[_error]() * bdi_writeout_inc() -> wb_writeout_inc() * stat init is moved to bdi_wb_init() and bdi_wb_exit() is added and frees stat. * 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. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'include/linux/backing-dev.h')
-rw-r--r--include/linux/backing-dev.h68
1 files changed, 32 insertions, 36 deletions
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index eb14f988a63e..fe7a907a4e16 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -36,15 +36,15 @@ enum wb_state {
typedef int (congested_fn)(void *, int);
-enum bdi_stat_item {
- BDI_RECLAIMABLE,
- BDI_WRITEBACK,
- BDI_DIRTIED,
- BDI_WRITTEN,
- NR_BDI_STAT_ITEMS
+enum wb_stat_item {
+ WB_RECLAIMABLE,
+ WB_WRITEBACK,
+ WB_DIRTIED,
+ WB_WRITTEN,
+ NR_WB_STAT_ITEMS
};
-#define BDI_STAT_BATCH (8*(1+ilog2(nr_cpu_ids)))
+#define WB_STAT_BATCH (8*(1+ilog2(nr_cpu_ids)))
struct bdi_writeback {
struct backing_dev_info *bdi; /* our parent bdi */
@@ -58,6 +58,8 @@ struct bdi_writeback {
struct list_head b_more_io; /* parked for more writeback */
struct list_head b_dirty_time; /* time stamps are dirty */
spinlock_t list_lock; /* protects the b_* lists */
+
+ struct percpu_counter stat[NR_WB_STAT_ITEMS];
};
struct backing_dev_info {
@@ -69,8 +71,6 @@ struct backing_dev_info {
char *name;
- struct percpu_counter bdi_stat[NR_BDI_STAT_ITEMS];
-
unsigned long bw_time_stamp; /* last time write bw is updated */
unsigned long dirtied_stamp;
unsigned long written_stamp; /* pages written at bw_time_stamp */
@@ -137,78 +137,74 @@ static inline int wb_has_dirty_io(struct bdi_writeback *wb)
!list_empty(&wb->b_more_io);
}
-static inline void __add_bdi_stat(struct backing_dev_info *bdi,
- enum bdi_stat_item item, s64 amount)
+static inline void __add_wb_stat(struct bdi_writeback *wb,
+ enum wb_stat_item item, s64 amount)
{
- __percpu_counter_add(&bdi->bdi_stat[item], amount, BDI_STAT_BATCH);
+ __percpu_counter_add(&wb->stat[item], amount, WB_STAT_BATCH);
}
-static inline void __inc_bdi_stat(struct backing_dev_info *bdi,
- enum bdi_stat_item item)
+static inline void __inc_wb_stat(struct bdi_writeback *wb,
+ enum wb_stat_item item)
{
- __add_bdi_stat(bdi, item, 1);
+ __add_wb_stat(wb, item, 1);
}
-static inline void inc_bdi_stat(struct backing_dev_info *bdi,
- enum bdi_stat_item item)
+static inline void inc_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
{
unsigned long flags;
local_irq_save(flags);
- __inc_bdi_stat(bdi, item);
+ __inc_wb_stat(wb, item);
local_irq_restore(flags);
}
-static inline void __dec_bdi_stat(struct backing_dev_info *bdi,
- enum bdi_stat_item item)
+static inline void __dec_wb_stat(struct bdi_writeback *wb,
+ enum wb_stat_item item)
{
- __add_bdi_stat(bdi, item, -1);
+ __add_wb_stat(wb, item, -1);
}
-static inline void dec_bdi_stat(struct backing_dev_info *bdi,
- enum bdi_stat_item item)
+static inline void dec_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
{
unsigned long flags;
local_irq_save(flags);
- __dec_bdi_stat(bdi, item);
+ __dec_wb_stat(wb, item);
local_irq_restore(flags);
}
-static inline s64 bdi_stat(struct backing_dev_info *bdi,
- enum bdi_stat_item item)
+static inline s64 wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
{
- return percpu_counter_read_positive(&bdi->bdi_stat[item]);
+ return percpu_counter_read_positive(&wb->stat[item]);
}
-static inline s64 __bdi_stat_sum(struct backing_dev_info *bdi,
- enum bdi_stat_item item)
+static inline s64 __wb_stat_sum(struct bdi_writeback *wb,
+ enum wb_stat_item item)
{
- return percpu_counter_sum_positive(&bdi->bdi_stat[item]);
+ return percpu_counter_sum_positive(&wb->stat[item]);
}
-static inline s64 bdi_stat_sum(struct backing_dev_info *bdi,
- enum bdi_stat_item item)
+static inline s64 wb_stat_sum(struct bdi_writeback *wb, enum wb_stat_item item)
{
s64 sum;
unsigned long flags;
local_irq_save(flags);
- sum = __bdi_stat_sum(bdi, item);
+ sum = __wb_stat_sum(wb, item);
local_irq_restore(flags);
return sum;
}
-extern void bdi_writeout_inc(struct backing_dev_info *bdi);
+extern void wb_writeout_inc(struct bdi_writeback *wb);
/*
* maximal error of a stat counter.
*/
-static inline unsigned long bdi_stat_error(struct backing_dev_info *bdi)
+static inline unsigned long wb_stat_error(struct bdi_writeback *wb)
{
#ifdef CONFIG_SMP
- return nr_cpu_ids * BDI_STAT_BATCH;
+ return nr_cpu_ids * WB_STAT_BATCH;
#else
return 1;
#endif