Skip to content

Commit

Permalink
blobstore: dynamic allocation of request set object pool
Browse files Browse the repository at this point in the history 
With large number of volumes and/or snapshots, a blobstore may
run out of "request set" objects that are used to perform metadata I/O.
The "request sets" are allocated from per-channel object pools, which
are limited by 512 items by default. This effectively limits number of
simultaneous metadata I/O requests.
This commit enables a dynamic growth of per-channel "request set" pools.

Signed-off-by: Dmitry Savitskiy <[email protected]>
  • Loading branch information
@dsavitskiy
dsavitskiy committed Feb 20, 2024
1 parent 817317b commit 29e5e50
Show file tree
Hide file tree
Showing 4 changed files with 123 additions and 42 deletions.
20 changes: 4 additions & 16 deletions lib/blob/blobstore.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3402,37 +3402,25 @@ bs_channel_create(void *io_device, void *ctx_buf)
struct spdk_blob_store *bs = io_device;
struct spdk_bs_channel *channel = ctx_buf;
struct spdk_bs_dev *dev;
uint32_t max_ops = bs->max_channel_ops;
uint32_t i;

dev = bs->dev;

channel->req_mem = calloc(max_ops, sizeof(struct spdk_bs_request_set));
if (!channel->req_mem) {
return -1;
}

TAILQ_INIT(&channel->reqs);

for (i = 0; i < max_ops; i++) {
TAILQ_INSERT_TAIL(&channel->reqs, &channel->req_mem[i], link);
}

channel->bs = bs;
channel->dev = dev;
bs_request_set_pool_init(&channel->req_pool);
channel->dev_channel = dev->create_channel(dev);

if (!channel->dev_channel) {
SPDK_ERRLOG("Failed to create device channel.\n");
free(channel->req_mem);
bs_request_set_pool_free(&channel->req_pool);
return -1;
}

channel->new_cluster_page = spdk_zmalloc(SPDK_BS_PAGE_SIZE, 0, NULL, SPDK_ENV_SOCKET_ID_ANY,
SPDK_MALLOC_DMA);
if (!channel->new_cluster_page) {
SPDK_ERRLOG("Failed to allocate new cluster page\n");
free(channel->req_mem);
bs_request_set_pool_free(&channel->req_pool);
channel->dev->destroy_channel(channel->dev, channel->dev_channel);
return -1;
}
Expand Down Expand Up @@ -3464,7 +3452,7 @@ bs_channel_destroy(void *io_device, void *ctx_buf)

blob_esnap_destroy_bs_channel(channel);

free(channel->req_mem);
bs_request_set_pool_free(&channel->req_pool);
spdk_free(channel->new_cluster_page);
channel->dev->destroy_channel(channel->dev, channel->dev_channel);
}
Expand Down
3 changes: 1 addition & 2 deletions lib/blob/blobstore.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -203,8 +203,7 @@ struct spdk_blob_store {
};

struct spdk_bs_channel {
struct spdk_bs_request_set *req_mem;
TAILQ_HEAD(, spdk_bs_request_set) reqs;
struct spdk_bs_request_set_pool req_pool;

struct spdk_blob_store *bs;

Expand Down
132 changes: 108 additions & 24 deletions lib/blob/request.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,105 @@

#include "spdk/log.h"

void
bs_request_set_pool_init(struct spdk_bs_request_set_pool *req_pool)
{
req_pool->req_mem = NULL;
TAILQ_INIT(&req_pool->reqs);
}

void
bs_request_set_pool_free(struct spdk_bs_request_set_pool *req_pool)
{
struct spdk_bs_request_set **ps = req_pool->req_mem;

if (ps != NULL) {
while (*ps != NULL) {
free(*ps);
++ps;
}
free(req_pool->req_mem);
req_pool->req_mem = NULL;
}
}

static int
bs_request_set_pool_grow(struct spdk_bs_request_set_pool *req_pool,
uint32_t max_ops)
{
struct spdk_bs_request_set **ps;
struct spdk_bs_request_set *new_set;
uint32_t i;

/* Allocate a new chunk of spdk_bs_request_set elements */
new_set = calloc(max_ops, sizeof(struct spdk_bs_request_set));
if (!new_set) {
return -ENOMEM;
}

/* Count the number of existing chunks and grow it by 1 */
i = 0;
if (req_pool->req_mem != NULL) {
ps = req_pool->req_mem;
while (*ps++ != NULL) {
++i;
}
}
++i;

ps = realloc(req_pool->req_mem, (i + 1) * sizeof(struct spdk_bs_request_set *));
if (!ps) {
free(new_set);
return -ENOMEM;
}
ps[i - 1] = new_set;
ps[i] = NULL; /* Final NULL element indicates end of the list */
req_pool->req_mem = ps;

/* Append the elements from the new chunk to the list of free requests */
for (i = 0; i < max_ops; i++) {
TAILQ_INSERT_TAIL(&req_pool->reqs, &new_set[i], link);
}

return 0;
}

static struct spdk_bs_request_set *
bs_request_set_alloc(struct spdk_bs_channel *channel, struct spdk_bs_cpl *cpl,
struct spdk_io_channel *back_channel)
{
struct spdk_bs_request_set *set = NULL;

if (channel->req_pool.req_mem != NULL) {
set = TAILQ_FIRST(&channel->req_pool.reqs);
}

if (!set) {
if (bs_request_set_pool_grow(&channel->req_pool,
channel->bs->max_channel_ops) < 0) {
SPDK_ERRLOG("Failed to allocate per-channel request set pool\n");
return NULL;
}
}

set = TAILQ_FIRST(&channel->req_pool.reqs);
assert(set);
TAILQ_REMOVE(&channel->req_pool.reqs, set, link);

set->cpl = *cpl;
set->bserrno = 0;
set->channel = channel;
set->back_channel = back_channel;

return set;
}

static inline void
bs_request_set_dealloc(struct spdk_bs_request_set *set)
{
TAILQ_INSERT_TAIL(&set->channel->req_pool.reqs, set, link);
}

void
bs_call_cpl(struct spdk_bs_cpl *cpl, int bserrno)
{
Expand Down Expand Up @@ -58,8 +157,7 @@ bs_request_set_complete(struct spdk_bs_request_set *set)
struct spdk_bs_cpl cpl = set->cpl;
int bserrno = set->bserrno;

TAILQ_INSERT_TAIL(&set->channel->reqs, set, link);

bs_request_set_dealloc(set);
bs_call_cpl(&cpl, bserrno);
}

Expand All @@ -81,16 +179,11 @@ bs_sequence_start(struct spdk_io_channel *_channel, struct spdk_bs_cpl *cpl,

channel = spdk_io_channel_get_ctx(_channel);
assert(channel != NULL);
set = TAILQ_FIRST(&channel->reqs);

set = bs_request_set_alloc(channel, cpl, back_channel);
if (!set) {
return NULL;
}
TAILQ_REMOVE(&channel->reqs, set, link);

set->cpl = *cpl;
set->bserrno = 0;
set->channel = channel;
set->back_channel = back_channel;

set->cb_args.cb_fn = bs_sequence_completion;
set->cb_args.cb_arg = set;
Expand Down Expand Up @@ -340,16 +433,11 @@ bs_batch_open(struct spdk_io_channel *_channel, struct spdk_bs_cpl *cpl, struct

channel = spdk_io_channel_get_ctx(_channel);
assert(channel != NULL);
set = TAILQ_FIRST(&channel->reqs);

set = bs_request_set_alloc(channel, cpl, back_channel);
if (!set) {
return NULL;
}
TAILQ_REMOVE(&channel->reqs, set, link);

set->cpl = *cpl;
set->bserrno = 0;
set->channel = channel;
set->back_channel = back_channel;

set->u.batch.cb_fn = NULL;
set->u.batch.cb_arg = NULL;
Expand Down Expand Up @@ -477,15 +565,11 @@ bs_user_op_alloc(struct spdk_io_channel *_channel, struct spdk_bs_cpl *cpl,

channel = spdk_io_channel_get_ctx(_channel);
assert(channel != NULL);
set = TAILQ_FIRST(&channel->reqs);

set = bs_request_set_alloc(channel, cpl, NULL);
if (!set) {
return NULL;
}
TAILQ_REMOVE(&channel->reqs, set, link);

set->cpl = *cpl;
set->channel = channel;
set->back_channel = NULL;
set->ext_io_opts = NULL;

args = &set->u.user_op;
Expand Down Expand Up @@ -541,7 +625,7 @@ bs_user_op_execute(spdk_bs_user_op_t *op)
set->ext_io_opts);
break;
}
TAILQ_INSERT_TAIL(&set->channel->reqs, set, link);
bs_request_set_dealloc(set);
}

void
Expand All @@ -552,7 +636,7 @@ bs_user_op_abort(spdk_bs_user_op_t *op, int bserrno)
set = (struct spdk_bs_request_set *)op;

set->cpl.u.blob_basic.cb_fn(set->cpl.u.blob_basic.cb_arg, bserrno);
TAILQ_INSERT_TAIL(&set->channel->reqs, set, link);
bs_request_set_dealloc(set);
}

SPDK_LOG_REGISTER_COMPONENT(blob_rw)
10 changes: 10 additions & 0 deletions lib/blob/request.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -127,6 +127,16 @@ struct spdk_bs_request_set {
TAILQ_ENTRY(spdk_bs_request_set) link;
};

/* A pool of pre-allocated requested sets. */
struct spdk_bs_request_set_pool {
struct spdk_bs_request_set **req_mem;
TAILQ_HEAD(, spdk_bs_request_set) reqs;
};

void bs_request_set_pool_init(struct spdk_bs_request_set_pool *req_pool);

void bs_request_set_pool_free(struct spdk_bs_request_set_pool *req_pool);

void bs_call_cpl(struct spdk_bs_cpl *cpl, int bserrno);

spdk_bs_sequence_t *bs_sequence_start_bs(struct spdk_io_channel *channel,
Expand Down

0 comments on commit 29e5e50

Please sign in to comment.