c/mirror_zfs
1
0
Fork 0
mirror of https://git.proxmox.com/git/mirror_zfs.git synced 2026-05-23 19:04:45 +03:00
Code Issues Packages Projects Releases Wiki Activity

Revert "Pre-allocate vdev I/O buffers"

Browse Source 
Commit 86dd0fd added preallocated I/O buffers.  This is no longer
required after the recent kmem changes designed to make our memory
allocation interfaces behave more like those found on Illumos.  A
deadlock in this situation is no longer possible.

However, these allocations still have the potential to be expensive.
So a potential future optimization might be to perform then KM_NOSLEEP
so that they either succeed of fail quicky.  Either case is acceptable
here because we can safely abort the aggregation.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This commit is contained in:
Brian Behlendorf
2014-12-12 16:40:21 -08:00
parent 60e1eda929
commit 285b29d959
4 changed files with 2 additions and 72 deletions
Download Patch File Download Diff File Expand all files Collapse all files
module/zfs/vdev_queue.c
+2 -41
View File
@@ -328,9 +328,7 @@ void
vdev_queue_init(vdev_t *vd)
{
vdev_queue_t *vq = &vd->vdev_queue;
int max_active_sum;
zio_priority_t p;
int i;
mutex_init(&vq->vq_lock, NULL, MUTEX_DEFAULT, NULL);
vq->vq_vdev = vd;
@@ -352,39 +350,18 @@ vdev_queue_init(vdev_t *vd)
vdev_queue_offset_compare,
sizeof (zio_t), offsetof(struct zio, io_queue_node));
}
/*
* A list of buffers which can be used for aggregate I/O, this
* avoids the need to allocate them on demand when memory is low.
*/
list_create(&vq->vq_io_list, sizeof (vdev_io_t),
offsetof(vdev_io_t, vi_node));
max_active_sum = zfs_vdev_sync_read_max_active +
zfs_vdev_sync_write_max_active + zfs_vdev_async_read_max_active +
zfs_vdev_async_write_max_active + zfs_vdev_scrub_max_active;
for (i = 0; i < max_active_sum; i++)
list_insert_tail(&vq->vq_io_list, zio_vdev_alloc());
}
void
vdev_queue_fini(vdev_t *vd)
{
vdev_queue_t *vq = &vd->vdev_queue;
vdev_io_t *vi;
zio_priority_t p;
for (p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++)
avl_destroy(&vq->vq_class[p].vqc_queued_tree);
avl_destroy(&vq->vq_active_tree);
while ((vi = list_head(&vq->vq_io_list)) != NULL) {
list_remove(&vq->vq_io_list, vi);
zio_vdev_free(vi);
}
list_destroy(&vq->vq_io_list);
mutex_destroy(&vq->vq_lock);
}
@@ -468,9 +445,6 @@ vdev_queue_pending_remove(vdev_queue_t *vq, zio_t *zio)
static void
vdev_queue_agg_io_done(zio_t *aio)
{
vdev_queue_t *vq = &aio->io_vd->vdev_queue;
vdev_io_t *vi = aio->io_data;
if (aio->io_type == ZIO_TYPE_READ) {
zio_t *pio;
while ((pio = zio_walk_parents(aio)) != NULL) {
@@ -479,9 +453,7 @@ vdev_queue_agg_io_done(zio_t *aio)
}
}
mutex_enter(&vq->vq_lock);
list_insert_tail(&vq->vq_io_list, vi);
mutex_exit(&vq->vq_lock);
zio_buf_free(aio->io_data, aio->io_size);
}
/*
@@ -496,7 +468,6 @@ vdev_queue_agg_io_done(zio_t *aio)
static zio_t *
vdev_queue_aggregate(vdev_queue_t *vq, zio_t *zio)
{
vdev_io_t *vi;
zio_t *first, *last, *aio, *dio, *mandatory, *nio;
uint64_t maxgap = 0;
uint64_t size;
@@ -529,12 +500,6 @@ vdev_queue_aggregate(vdev_queue_t *vq, zio_t *zio)
if (zio->io_type == ZIO_TYPE_READ)
maxgap = zfs_vdev_read_gap_limit;
vi = list_head(&vq->vq_io_list);
if (vi == NULL) {
vi = zio_vdev_alloc();
list_insert_head(&vq->vq_io_list, vi);
}
/*
* We can aggregate I/Os that are sufficiently adjacent and of
* the same flavor, as expressed by the AGG_INHERIT flags.
@@ -622,13 +587,11 @@ vdev_queue_aggregate(vdev_queue_t *vq, zio_t *zio)
if (first == last)
return (NULL);
ASSERT(vi != NULL);
size = IO_SPAN(first, last);
ASSERT3U(size, <=, zfs_vdev_aggregation_limit);
aio = zio_vdev_delegated_io(first->io_vd, first->io_offset,
vi, size, first->io_type, zio->io_priority,
zio_buf_alloc(size), size, first->io_type, zio->io_priority,
flags | ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE,
vdev_queue_agg_io_done, NULL);
aio->io_timestamp = first->io_timestamp;
@@ -655,8 +618,6 @@ vdev_queue_aggregate(vdev_queue_t *vq, zio_t *zio)
zio_execute(dio);
} while (dio != last);
list_remove(&vq->vq_io_list, vi);
return (aio);
}