2022-02-10 06:00:07

by NeilBrown

[permalink] [raw]
Subject: [PATCH 11/11] Remove congestion tracking framework.

This framework is no longer used - so discard it.

Signed-off-by: NeilBrown <[email protected]>
---
include/linux/backing-dev-defs.h | 8 -----
include/linux/backing-dev.h | 2 -
include/trace/events/writeback.h | 28 -------------------
mm/backing-dev.c | 57 --------------------------------------
4 files changed, 95 deletions(-)

diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h
index 993c5628a726..e863c88df95f 100644
--- a/include/linux/backing-dev-defs.h
+++ b/include/linux/backing-dev-defs.h
@@ -207,14 +207,6 @@ struct backing_dev_info {
#endif
};

-enum {
- BLK_RW_ASYNC = 0,
- BLK_RW_SYNC = 1,
-};
-
-void clear_bdi_congested(struct backing_dev_info *bdi, int sync);
-void set_bdi_congested(struct backing_dev_info *bdi, int sync);
-
struct wb_lock_cookie {
bool locked;
unsigned long flags;
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 2d764566280c..87ce24d238f3 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -135,8 +135,6 @@ static inline bool writeback_in_progress(struct bdi_writeback *wb)

struct backing_dev_info *inode_to_bdi(struct inode *inode);

-long congestion_wait(int sync, long timeout);
-
static inline bool mapping_can_writeback(struct address_space *mapping)
{
return inode_to_bdi(mapping->host)->capabilities & BDI_CAP_WRITEBACK;
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index a345b1e12daf..86b2a82da546 100644
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -735,34 +735,6 @@ TRACE_EVENT(writeback_sb_inodes_requeue,
)
);

-DECLARE_EVENT_CLASS(writeback_congest_waited_template,
-
- TP_PROTO(unsigned int usec_timeout, unsigned int usec_delayed),
-
- TP_ARGS(usec_timeout, usec_delayed),
-
- TP_STRUCT__entry(
- __field( unsigned int, usec_timeout )
- __field( unsigned int, usec_delayed )
- ),
-
- TP_fast_assign(
- __entry->usec_timeout = usec_timeout;
- __entry->usec_delayed = usec_delayed;
- ),
-
- TP_printk("usec_timeout=%u usec_delayed=%u",
- __entry->usec_timeout,
- __entry->usec_delayed)
-);
-
-DEFINE_EVENT(writeback_congest_waited_template, writeback_congestion_wait,
-
- TP_PROTO(unsigned int usec_timeout, unsigned int usec_delayed),
-
- TP_ARGS(usec_timeout, usec_delayed)
-);
-
DECLARE_EVENT_CLASS(writeback_single_inode_template,

TP_PROTO(struct inode *inode,
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index eae96dfe0261..7176af65b103 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -1005,60 +1005,3 @@ const char *bdi_dev_name(struct backing_dev_info *bdi)
return bdi->dev_name;
}
EXPORT_SYMBOL_GPL(bdi_dev_name);
-
-static wait_queue_head_t congestion_wqh[2] = {
- __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]),
- __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1])
- };
-static atomic_t nr_wb_congested[2];
-
-void clear_bdi_congested(struct backing_dev_info *bdi, int sync)
-{
- wait_queue_head_t *wqh = &congestion_wqh[sync];
- enum wb_congested_state bit;
-
- bit = sync ? WB_sync_congested : WB_async_congested;
- if (test_and_clear_bit(bit, &bdi->wb.congested))
- atomic_dec(&nr_wb_congested[sync]);
- smp_mb__after_atomic();
- if (waitqueue_active(wqh))
- wake_up(wqh);
-}
-EXPORT_SYMBOL(clear_bdi_congested);
-
-void set_bdi_congested(struct backing_dev_info *bdi, int sync)
-{
- enum wb_congested_state bit;
-
- bit = sync ? WB_sync_congested : WB_async_congested;
- if (!test_and_set_bit(bit, &bdi->wb.congested))
- atomic_inc(&nr_wb_congested[sync]);
-}
-EXPORT_SYMBOL(set_bdi_congested);
-
-/**
- * congestion_wait - wait for a backing_dev to become uncongested
- * @sync: SYNC or ASYNC IO
- * @timeout: timeout in jiffies
- *
- * Waits for up to @timeout jiffies for a backing_dev (any backing_dev) to exit
- * write congestion. If no backing_devs are congested then just wait for the
- * next write to be completed.
- */
-long congestion_wait(int sync, long timeout)
-{
- long ret;
- unsigned long start = jiffies;
- DEFINE_WAIT(wait);
- wait_queue_head_t *wqh = &congestion_wqh[sync];
-
- prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
- ret = io_schedule_timeout(timeout);
- finish_wait(wqh, &wait);
-
- trace_writeback_congestion_wait(jiffies_to_usecs(timeout),
- jiffies_to_usecs(jiffies - start));
-
- return ret;
-}
-EXPORT_SYMBOL(congestion_wait);