| Message ID | 1432329245-5844-22-git-send-email-tj@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri 22-05-15 17:13:35, Tejun Heo wrote: > Currently, a wb's (bdi_writeback) congestion state is carried in its > ->state field; however, cgroup writeback support will require multiple > wb's sharing the same congestion state. This patch separates out > congestion state into its own struct - struct bdi_writeback_congested. > A new field wb field, wb_congested, points to its associated congested > struct. The default wb, bdi->wb, always points to bdi->wb_congested. > > While this patch adds a layer of indirection, it doesn't introduce any > behavior changes. > > Signed-off-by: Tejun Heo <tj@kernel.org> Looks good. You can add: Reviewed-by: Jan Kara <jack@suse.com> Honza > --- > include/linux/backing-dev-defs.h | 14 ++++++++++++-- > include/linux/backing-dev.h | 2 +- > mm/backing-dev.c | 7 +++++-- > 3 files changed, 18 insertions(+), 5 deletions(-) > > diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h > index aa18c4b..9e9eafa 100644 > --- a/include/linux/backing-dev-defs.h > +++ b/include/linux/backing-dev-defs.h > @@ -16,12 +16,15 @@ struct dentry; > * Bits in bdi_writeback.state > */ > enum wb_state { > - WB_async_congested, /* The async (write) queue is getting full */ > - WB_sync_congested, /* The sync queue is getting full */ > WB_registered, /* bdi_register() was done */ > WB_writeback_running, /* Writeback is in progress */ > }; > > +enum wb_congested_state { > + WB_async_congested, /* The async (write) queue is getting full */ > + WB_sync_congested, /* The sync queue is getting full */ > +}; > + > typedef int (congested_fn)(void *, int); > > enum wb_stat_item { > @@ -34,6 +37,10 @@ enum wb_stat_item { > > #define WB_STAT_BATCH (8*(1+ilog2(nr_cpu_ids))) > > +struct bdi_writeback_congested { > + unsigned long state; /* WB_[a]sync_congested flags */ > +}; > + > struct bdi_writeback { > struct backing_dev_info *bdi; /* our parent bdi */ > > @@ -48,6 +55,8 @@ struct bdi_writeback { > > struct percpu_counter stat[NR_WB_STAT_ITEMS]; > > + struct bdi_writeback_congested *congested; > + > 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 */ > @@ -84,6 +93,7 @@ struct backing_dev_info { > unsigned int max_ratio, max_prop_frac; > > struct bdi_writeback wb; /* default writeback info for this bdi */ > + struct bdi_writeback_congested wb_congested; > > struct device *dev; > > diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h > index 7857820..bfdaa18 100644 > --- a/include/linux/backing-dev.h > +++ b/include/linux/backing-dev.h > @@ -167,7 +167,7 @@ static inline int bdi_congested(struct backing_dev_info *bdi, int bdi_bits) > { > if (bdi->congested_fn) > return bdi->congested_fn(bdi->congested_data, bdi_bits); > - return (bdi->wb.state & bdi_bits); > + return (bdi->wb.congested->state & bdi_bits); > } > > static inline int bdi_read_congested(struct backing_dev_info *bdi) > diff --git a/mm/backing-dev.c b/mm/backing-dev.c > index 805b287..5ec7658 100644 > --- a/mm/backing-dev.c > +++ b/mm/backing-dev.c > @@ -383,6 +383,9 @@ int bdi_init(struct backing_dev_info *bdi) > if (err) > return err; > > + bdi->wb_congested.state = 0; > + bdi->wb.congested = &bdi->wb_congested; > + > return 0; > } > EXPORT_SYMBOL(bdi_init); > @@ -504,7 +507,7 @@ void clear_bdi_congested(struct backing_dev_info *bdi, int sync) > wait_queue_head_t *wqh = &congestion_wqh[sync]; > > bit = sync ? WB_sync_congested : WB_async_congested; > - if (test_and_clear_bit(bit, &bdi->wb.state)) > + if (test_and_clear_bit(bit, &bdi->wb.congested->state)) > atomic_dec(&nr_bdi_congested[sync]); > smp_mb__after_atomic(); > if (waitqueue_active(wqh)) > @@ -517,7 +520,7 @@ void set_bdi_congested(struct backing_dev_info *bdi, int sync) > enum wb_state bit; > > bit = sync ? WB_sync_congested : WB_async_congested; > - if (!test_and_set_bit(bit, &bdi->wb.state)) > + if (!test_and_set_bit(bit, &bdi->wb.congested->state)) > atomic_inc(&nr_bdi_congested[sync]); > } > EXPORT_SYMBOL(set_bdi_congested); > -- > 2.4.0 >
diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index aa18c4b..9e9eafa 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -16,12 +16,15 @@ struct dentry; * Bits in bdi_writeback.state */ enum wb_state { - WB_async_congested, /* The async (write) queue is getting full */ - WB_sync_congested, /* The sync queue is getting full */ WB_registered, /* bdi_register() was done */ WB_writeback_running, /* Writeback is in progress */ }; +enum wb_congested_state { + WB_async_congested, /* The async (write) queue is getting full */ + WB_sync_congested, /* The sync queue is getting full */ +}; + typedef int (congested_fn)(void *, int); enum wb_stat_item { @@ -34,6 +37,10 @@ enum wb_stat_item { #define WB_STAT_BATCH (8*(1+ilog2(nr_cpu_ids))) +struct bdi_writeback_congested { + unsigned long state; /* WB_[a]sync_congested flags */ +}; + struct bdi_writeback { struct backing_dev_info *bdi; /* our parent bdi */ @@ -48,6 +55,8 @@ struct bdi_writeback { struct percpu_counter stat[NR_WB_STAT_ITEMS]; + struct bdi_writeback_congested *congested; + 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 */ @@ -84,6 +93,7 @@ struct backing_dev_info { unsigned int max_ratio, max_prop_frac; struct bdi_writeback wb; /* default writeback info for this bdi */ + struct bdi_writeback_congested wb_congested; struct device *dev; diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 7857820..bfdaa18 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -167,7 +167,7 @@ static inline int bdi_congested(struct backing_dev_info *bdi, int bdi_bits) { if (bdi->congested_fn) return bdi->congested_fn(bdi->congested_data, bdi_bits); - return (bdi->wb.state & bdi_bits); + return (bdi->wb.congested->state & bdi_bits); } static inline int bdi_read_congested(struct backing_dev_info *bdi) diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 805b287..5ec7658 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -383,6 +383,9 @@ int bdi_init(struct backing_dev_info *bdi) if (err) return err; + bdi->wb_congested.state = 0; + bdi->wb.congested = &bdi->wb_congested; + return 0; } EXPORT_SYMBOL(bdi_init); @@ -504,7 +507,7 @@ void clear_bdi_congested(struct backing_dev_info *bdi, int sync) wait_queue_head_t *wqh = &congestion_wqh[sync]; bit = sync ? WB_sync_congested : WB_async_congested; - if (test_and_clear_bit(bit, &bdi->wb.state)) + if (test_and_clear_bit(bit, &bdi->wb.congested->state)) atomic_dec(&nr_bdi_congested[sync]); smp_mb__after_atomic(); if (waitqueue_active(wqh)) @@ -517,7 +520,7 @@ void set_bdi_congested(struct backing_dev_info *bdi, int sync) enum wb_state bit; bit = sync ? WB_sync_congested : WB_async_congested; - if (!test_and_set_bit(bit, &bdi->wb.state)) + if (!test_and_set_bit(bit, &bdi->wb.congested->state)) atomic_inc(&nr_bdi_congested[sync]); } EXPORT_SYMBOL(set_bdi_congested);
Currently, a wb's (bdi_writeback) congestion state is carried in its ->state field; however, cgroup writeback support will require multiple wb's sharing the same congestion state. This patch separates out congestion state into its own struct - struct bdi_writeback_congested. A new field wb field, wb_congested, points to its associated congested struct. The default wb, bdi->wb, always points to bdi->wb_congested. While this patch adds a layer of indirection, it doesn't introduce any behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> --- include/linux/backing-dev-defs.h | 14 ++++++++++++-- include/linux/backing-dev.h | 2 +- mm/backing-dev.c | 7 +++++-- 3 files changed, 18 insertions(+), 5 deletions(-)