5c0de3d72f
Commit 95b88f4d71 ("dm writecache: pause
writeback if cache full and origin being written directly") introduced a
code that pauses cache flushing if we are issuing writes directly to the
origin.
Improve that initial commit by making the timeout code configurable
(via the option "pause_writeback"). Also change the default from 1s to
3s because it performed better.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
82 lines
1.5 KiB
C
82 lines
1.5 KiB
C
/*
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* Copyright (C) 2021 Red Hat, Inc. All rights reserved.
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*
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* This file is released under the GPL.
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*/
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#ifndef DM_IO_TRACKER_H
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#define DM_IO_TRACKER_H
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#include <linux/jiffies.h>
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struct dm_io_tracker {
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spinlock_t lock;
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/*
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* Sectors of in-flight IO.
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*/
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sector_t in_flight;
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/*
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* The time, in jiffies, when this device became idle
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* (if it is indeed idle).
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*/
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unsigned long idle_time;
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unsigned long last_update_time;
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};
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static inline void dm_iot_init(struct dm_io_tracker *iot)
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{
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spin_lock_init(&iot->lock);
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iot->in_flight = 0ul;
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iot->idle_time = 0ul;
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iot->last_update_time = jiffies;
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}
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static inline bool dm_iot_idle_for(struct dm_io_tracker *iot, unsigned long j)
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{
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bool r = false;
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spin_lock_irq(&iot->lock);
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if (!iot->in_flight)
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r = time_after(jiffies, iot->idle_time + j);
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spin_unlock_irq(&iot->lock);
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return r;
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}
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static inline unsigned long dm_iot_idle_time(struct dm_io_tracker *iot)
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{
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unsigned long r = 0;
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spin_lock_irq(&iot->lock);
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if (!iot->in_flight)
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r = jiffies - iot->idle_time;
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spin_unlock_irq(&iot->lock);
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return r;
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}
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static inline void dm_iot_io_begin(struct dm_io_tracker *iot, sector_t len)
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{
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spin_lock_irq(&iot->lock);
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iot->in_flight += len;
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spin_unlock_irq(&iot->lock);
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}
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static inline void dm_iot_io_end(struct dm_io_tracker *iot, sector_t len)
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{
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unsigned long flags;
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if (!len)
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return;
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spin_lock_irqsave(&iot->lock, flags);
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iot->in_flight -= len;
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if (!iot->in_flight)
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iot->idle_time = jiffies;
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spin_unlock_irqrestore(&iot->lock, flags);
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}
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#endif
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