block/block-copy: use aio-task-pool API

Run block_copy iterations in parallel in aio tasks.

Changes:
  - BlockCopyTask becomes aio task structure. Add zeroes field to pass
    it to block_copy_do_copy
  - add call state - it's a state of one call of block_copy(), shared
    between parallel tasks. For now used only to keep information about
    first error: is it read or not.
  - convert block_copy_dirty_clusters to aio-task loop.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200429130847.28124-6-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2020-04-29 16:08:47 +03:00 committed by Max Reitz
parent 42ac214406
commit 4ce5dd3e9b
1 changed files with 106 additions and 13 deletions

View File

@ -19,15 +19,29 @@
#include "block/block-copy.h"
#include "sysemu/block-backend.h"
#include "qemu/units.h"
#include "qemu/coroutine.h"
#include "block/aio_task.h"
#define BLOCK_COPY_MAX_COPY_RANGE (16 * MiB)
#define BLOCK_COPY_MAX_BUFFER (1 * MiB)
#define BLOCK_COPY_MAX_MEM (128 * MiB)
#define BLOCK_COPY_MAX_WORKERS 64
static coroutine_fn int block_copy_task_entry(AioTask *task);
typedef struct BlockCopyCallState {
bool failed;
bool error_is_read;
} BlockCopyCallState;
typedef struct BlockCopyTask {
AioTask task;
BlockCopyState *s;
BlockCopyCallState *call_state;
int64_t offset;
int64_t bytes;
bool zeroes;
QLIST_ENTRY(BlockCopyTask) list;
CoQueue wait_queue; /* coroutines blocked on this task */
} BlockCopyTask;
@ -116,6 +130,7 @@ static bool coroutine_fn block_copy_wait_one(BlockCopyState *s, int64_t offset,
* the beginning of it.
*/
static BlockCopyTask *block_copy_task_create(BlockCopyState *s,
BlockCopyCallState *call_state,
int64_t offset, int64_t bytes)
{
BlockCopyTask *task;
@ -135,7 +150,9 @@ static BlockCopyTask *block_copy_task_create(BlockCopyState *s,
task = g_new(BlockCopyTask, 1);
*task = (BlockCopyTask) {
.task.func = block_copy_task_entry,
.s = s,
.call_state = call_state,
.offset = offset,
.bytes = bytes,
};
@ -263,6 +280,38 @@ void block_copy_set_progress_meter(BlockCopyState *s, ProgressMeter *pm)
s->progress = pm;
}
/*
* Takes ownership of @task
*
* If pool is NULL directly run the task, otherwise schedule it into the pool.
*
* Returns: task.func return code if pool is NULL
* otherwise -ECANCELED if pool status is bad
* otherwise 0 (successfully scheduled)
*/
static coroutine_fn int block_copy_task_run(AioTaskPool *pool,
BlockCopyTask *task)
{
if (!pool) {
int ret = task->task.func(&task->task);
g_free(task);
return ret;
}
aio_task_pool_wait_slot(pool);
if (aio_task_pool_status(pool) < 0) {
co_put_to_shres(task->s->mem, task->bytes);
block_copy_task_end(task, -ECANCELED);
g_free(task);
return -ECANCELED;
}
aio_task_pool_start_task(pool, &task->task);
return 0;
}
/*
* block_copy_do_copy
*
@ -366,6 +415,27 @@ out:
return ret;
}
static coroutine_fn int block_copy_task_entry(AioTask *task)
{
BlockCopyTask *t = container_of(task, BlockCopyTask, task);
bool error_is_read;
int ret;
ret = block_copy_do_copy(t->s, t->offset, t->bytes, t->zeroes,
&error_is_read);
if (ret < 0 && !t->call_state->failed) {
t->call_state->failed = true;
t->call_state->error_is_read = error_is_read;
} else {
progress_work_done(t->s->progress, t->bytes);
t->s->progress_bytes_callback(t->bytes, t->s->progress_opaque);
}
co_put_to_shres(t->s->mem, t->bytes);
block_copy_task_end(t, ret);
return ret;
}
static int block_copy_block_status(BlockCopyState *s, int64_t offset,
int64_t bytes, int64_t *pnum)
{
@ -484,6 +554,8 @@ static int coroutine_fn block_copy_dirty_clusters(BlockCopyState *s,
int ret = 0;
bool found_dirty = false;
int64_t end = offset + bytes;
AioTaskPool *aio = NULL;
BlockCopyCallState call_state = {false, false};
/*
* block_copy() user is responsible for keeping source and target in same
@ -495,11 +567,11 @@ static int coroutine_fn block_copy_dirty_clusters(BlockCopyState *s,
assert(QEMU_IS_ALIGNED(offset, s->cluster_size));
assert(QEMU_IS_ALIGNED(bytes, s->cluster_size));
while (bytes) {
g_autofree BlockCopyTask *task = NULL;
while (bytes && aio_task_pool_status(aio) == 0) {
BlockCopyTask *task;
int64_t status_bytes;
task = block_copy_task_create(s, offset, bytes);
task = block_copy_task_create(s, &call_state, offset, bytes);
if (!task) {
/* No more dirty bits in the bitmap */
trace_block_copy_skip_range(s, offset, bytes);
@ -519,6 +591,7 @@ static int coroutine_fn block_copy_dirty_clusters(BlockCopyState *s,
}
if (s->skip_unallocated && !(ret & BDRV_BLOCK_ALLOCATED)) {
block_copy_task_end(task, 0);
g_free(task);
progress_set_remaining(s->progress,
bdrv_get_dirty_count(s->copy_bitmap) +
s->in_flight_bytes);
@ -527,25 +600,45 @@ static int coroutine_fn block_copy_dirty_clusters(BlockCopyState *s,
bytes = end - offset;
continue;
}
task->zeroes = ret & BDRV_BLOCK_ZERO;
trace_block_copy_process(s, task->offset);
co_get_from_shres(s->mem, task->bytes);
ret = block_copy_do_copy(s, task->offset, task->bytes,
ret & BDRV_BLOCK_ZERO, error_is_read);
co_put_to_shres(s->mem, task->bytes);
block_copy_task_end(task, ret);
if (ret < 0) {
return ret;
}
progress_work_done(s->progress, task->bytes);
s->progress_bytes_callback(task->bytes, s->progress_opaque);
offset = task_end(task);
bytes = end - offset;
if (!aio && bytes) {
aio = aio_task_pool_new(BLOCK_COPY_MAX_WORKERS);
}
ret = block_copy_task_run(aio, task);
if (ret < 0) {
goto out;
}
}
return found_dirty;
out:
if (aio) {
aio_task_pool_wait_all(aio);
/*
* We are not really interested in -ECANCELED returned from
* block_copy_task_run. If it fails, it means some task already failed
* for real reason, let's return first failure.
* Still, assert that we don't rewrite failure by success.
*/
assert(ret == 0 || aio_task_pool_status(aio) < 0);
ret = aio_task_pool_status(aio);
aio_task_pool_free(aio);
}
if (error_is_read && ret < 0) {
*error_is_read = call_state.error_is_read;
}
return ret < 0 ? ret : found_dirty;
}
/*