Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

[WIP; RFC, discussion, feedback] account for ashift when choosing buffers … #3451

Closed
wants to merge 1 commit into from
Closed

[WIP; RFC, discussion, feedback] account for ashift when choosing buffers … #3451

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
29 changes: 20 additions & 9 deletions module/zfs/arc.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5021,6 +5021,7 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz,
l2arc_buf_hdr_t *l2hdr;
kmutex_t *hash_lock;
uint64_t buf_sz;
uint64_t buf_a_sz;

if (arc_warm == B_FALSE)
ab_prev = list_next(list, ab);
Expand Down Expand Up @@ -5049,7 +5050,15 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz,
continue;
}

if ((write_sz + ab->b_size) > target_sz) {
/*
* Assume that the buffer is not going to be compressed
* and could take more space on disk because of a larger
* disk block size.
*/
buf_sz = ab->b_size;
buf_a_sz = vdev_psize_to_asize(dev->l2ad_vdev, buf_sz);

if ((write_asize + buf_a_sz) > target_sz) {
full = B_TRUE;
mutex_exit(hash_lock);
break;
Expand Down Expand Up @@ -5094,7 +5103,6 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz,
l2hdr->b_tmp_cdata = ab->b_buf->b_data;
l2hdr->b_hits = 0;

buf_sz = ab->b_size;
ab->b_l2hdr = l2hdr;

list_insert_head(dev->l2ad_buflist, ab);
Expand All @@ -5109,6 +5117,7 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz,
mutex_exit(hash_lock);

write_sz += buf_sz;
write_asize += buf_a_sz;
}

mutex_exit(list_lock);
Expand All @@ -5130,6 +5139,7 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz,
* and work backwards, retracing the course of the buffer selector
* loop above.
*/
write_asize = 0;
for (ab = list_prev(dev->l2ad_buflist, head); ab;
ab = list_prev(dev->l2ad_buflist, ab)) {
l2arc_buf_hdr_t *l2hdr;
Expand Down Expand Up @@ -5172,7 +5182,7 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz,

/* Compression may have squashed the buffer to zero length. */
if (buf_sz != 0) {
uint64_t buf_p_sz;
uint64_t buf_a_sz;

wzio = zio_write_phys(pio, dev->l2ad_vdev,
dev->l2ad_hand, buf_sz, buf_data, ZIO_CHECKSUM_OFF,
Expand All @@ -5183,13 +5193,14 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz,
zio_t *, wzio);
(void) zio_nowait(wzio);

write_asize += buf_sz;
write_psize += buf_sz;

/*
* Keep the clock hand suitably device-aligned.
*/
buf_p_sz = vdev_psize_to_asize(dev->l2ad_vdev, buf_sz);
write_psize += buf_p_sz;
dev->l2ad_hand += buf_p_sz;
buf_a_sz = vdev_psize_to_asize(dev->l2ad_vdev, buf_sz);
write_asize += buf_a_sz;
dev->l2ad_hand += buf_a_sz;
}
}

Expand All @@ -5199,8 +5210,8 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz,
ARCSTAT_BUMP(arcstat_l2_writes_sent);
ARCSTAT_INCR(arcstat_l2_write_bytes, write_asize);
ARCSTAT_INCR(arcstat_l2_size, write_sz);
ARCSTAT_INCR(arcstat_l2_asize, write_asize);
vdev_space_update(dev->l2ad_vdev, write_asize, 0, 0);
ARCSTAT_INCR(arcstat_l2_asize, write_psize);
vdev_space_update(dev->l2ad_vdev, write_psize, 0, 0);

/*
* Bump device hand to the device start if it is approaching the end.
Expand Down