bcache: Better full stripe scanning
The old scanning-by-stripe code burned too much CPU, this should be
better.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
index 60516bf..fe7d9d5 100644
--- a/drivers/md/bcache/writeback.h
+++ b/drivers/md/bcache/writeback.h
@@ -14,22 +14,27 @@
return ret;
}
-static inline bool bcache_dev_stripe_dirty(struct bcache_device *d,
+static inline unsigned offset_to_stripe(struct bcache_device *d,
+ uint64_t offset)
+{
+ do_div(offset, d->stripe_size);
+ return offset;
+}
+
+static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc,
uint64_t offset,
unsigned nr_sectors)
{
- uint64_t stripe = offset;
-
- do_div(stripe, d->stripe_size);
+ unsigned stripe = offset_to_stripe(&dc->disk, offset);
while (1) {
- if (atomic_read(d->stripe_sectors_dirty + stripe))
+ if (atomic_read(dc->disk.stripe_sectors_dirty + stripe))
return true;
- if (nr_sectors <= d->stripe_size)
+ if (nr_sectors <= dc->disk.stripe_size)
return false;
- nr_sectors -= d->stripe_size;
+ nr_sectors -= dc->disk.stripe_size;
stripe++;
}
}
@@ -45,7 +50,7 @@
return false;
if (dc->partial_stripes_expensive &&
- bcache_dev_stripe_dirty(&dc->disk, bio->bi_sector,
+ bcache_dev_stripe_dirty(dc, bio->bi_sector,
bio_sectors(bio)))
return true;