On Wed, 27 Jul 2011 13:03:52 -0700
"Bennett, Jeffrey" <jab@xxxxxxxx> wrote:
> Is there any "side effect" by doing this change?
NR_WORKER_THREADS is the number of threads that perform I/Os. So you
run more threads. You consume more memory.
> Is there any plan
> to make this a configuration option that can be changed with the
> tgt-adm command by the user?
tgtd should adjust NR_WORKER_THREADS dynamically since the optimal
value depends on your workload, hardware, etc. Well, until we
implement that feature, I think that we can support the boot option to
specify the number of I/O threads.
The following patch works for you? You can specify the number in the
following way:
tgtd --nr_iothreads=128
diff --git a/usr/bs.c b/usr/bs.c
index d72d090..6f67d15 100644
--- a/usr/bs.c
+++ b/usr/bs.c
@@ -24,6 +24,7 @@
#include <inttypes.h>
#include <pthread.h>
#include <stdio.h>
+#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
@@ -327,6 +328,11 @@ int bs_thread_open(struct bs_thread_info *info, request_func_t *rfn,
{
int i, ret;
+ info->worker_thread = zalloc(sizeof(pthread_t) * nr_threads);
+ if (!info->worker_thread)
+ return TGTADM_NOMEM;
+
+ eprintf("%d\n", nr_threads);
info->request_fn = rfn;
INIT_LIST_HEAD(&info->pending_list);
@@ -335,11 +341,6 @@ int bs_thread_open(struct bs_thread_info *info, request_func_t *rfn,
pthread_mutex_init(&info->pending_lock, NULL);
pthread_mutex_init(&info->startup_lock, NULL);
- if (nr_threads > ARRAY_SIZE(info->worker_thread)) {
- eprintf("too many threads %d\n", nr_threads);
- nr_threads = ARRAY_SIZE(info->worker_thread);
- }
-
pthread_mutex_lock(&info->startup_lock);
for (i = 0; i < nr_threads; i++) {
ret = pthread_create(&info->worker_thread[i], NULL,
@@ -353,6 +354,7 @@ int bs_thread_open(struct bs_thread_info *info, request_func_t *rfn,
}
}
pthread_mutex_unlock(&info->startup_lock);
+ info->nr_worker_threads = nr_threads;
return 0;
destroy_threads:
@@ -367,6 +369,7 @@ destroy_threads:
pthread_cond_destroy(&info->pending_cond);
pthread_mutex_destroy(&info->pending_lock);
pthread_mutex_destroy(&info->startup_lock);
+ free(info->worker_thread);
return TGTADM_NOMEM;
}
@@ -378,13 +381,13 @@ void bs_thread_close(struct bs_thread_info *info)
info->stop = 1;
pthread_cond_broadcast(&info->pending_cond);
- for (i = 0; info->worker_thread[i] &&
- i < ARRAY_SIZE(info->worker_thread); i++)
+ for (i = 0; info->worker_thread[i] && i < info->nr_worker_threads; i++)
pthread_join(info->worker_thread[i], NULL);
pthread_cond_destroy(&info->pending_cond);
pthread_mutex_destroy(&info->pending_lock);
pthread_mutex_destroy(&info->startup_lock);
+ free(info->worker_thread);
info->stop = 0;
}
diff --git a/usr/bs_rdwr.c b/usr/bs_rdwr.c
index 29db403..03b869d 100644
--- a/usr/bs_rdwr.c
+++ b/usr/bs_rdwr.c
@@ -148,11 +148,13 @@ static void bs_rdwr_close(struct scsi_lu *lu)
close(lu->fd);
}
+int nr_iothreads = 16;
+
static int bs_rdwr_init(struct scsi_lu *lu)
{
struct bs_thread_info *info = BS_THREAD_I(lu);
- return bs_thread_open(info, bs_rdwr_request, NR_WORKER_THREADS);
+ return bs_thread_open(info, bs_rdwr_request, nr_iothreads);
}
static void bs_rdwr_exit(struct scsi_lu *lu)
diff --git a/usr/bs_thread.h b/usr/bs_thread.h
index d460032..50dd1c3 100644
--- a/usr/bs_thread.h
+++ b/usr/bs_thread.h
@@ -1,9 +1,8 @@
-#define NR_WORKER_THREADS 4
-
typedef void (request_func_t) (struct scsi_cmd *);
struct bs_thread_info {
- pthread_t worker_thread[NR_WORKER_THREADS];
+ pthread_t *worker_thread;
+ int nr_worker_threads;
/* wokers sleep on this and signaled by tgtd */
pthread_cond_t pending_cond;
diff --git a/usr/tgtd.c b/usr/tgtd.c
index 5e07267..d5a512c 100644
--- a/usr/tgtd.c
+++ b/usr/tgtd.c
@@ -54,13 +54,14 @@ static struct option const long_options[] =
{
{"foreground", no_argument, 0, 'f'},
{"control-port", required_argument, 0, 'C'},
+ {"nr_iothreads", required_argument, 0, 't'},
{"debug", required_argument, 0, 'd'},
{"version", no_argument, 0, 'V'},
{"help", no_argument, 0, 'h'},
{0, 0, 0, 0},
};
-static char *short_options = "fC:d:Vh";
+static char *short_options = "fC:d:t:Vh";
static void usage(int status)
{
@@ -72,6 +73,7 @@ static void usage(int status)
Target framework daemon, version %s\n\
-f, --foreground make the program run in the foreground\n\
-C, --control-port NNNN use port NNNN for the mgmt channel\n\
+ -t, --nr_iothreads NNNN specify the number of I/O threads\n\
-d, --debug debuglevel print debugging information\n\
-V, --version print version and exit\n\
-h, --help display this help and exit\n\
@@ -500,6 +502,9 @@ int main(int argc, char **argv)
case 'C':
control_port = atoi(optarg);
break;
+ case 't':
+ nr_iothreads = atoi(optarg);
+ break;
case 'd':
is_debug = atoi(optarg);
break;
diff --git a/usr/tgtd.h b/usr/tgtd.h
index 032cb1c..8f61a07 100644
--- a/usr/tgtd.h
+++ b/usr/tgtd.h
@@ -210,6 +210,7 @@ enum mgmt_req_result {
extern int system_active;
extern int is_debug;
+extern int nr_iothreads;
extern int kspace_send_tsk_mgmt_res(struct mgmt_req *mreq);
extern int kspace_send_cmd_res(uint64_t nid, int result, struct scsi_cmd *);
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