Add thread_segments as needed
Setup segments in units of 8, and add extra ones as needed. This avoids
having to setup one huge segment upfront for the maximum number of jobs.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/backend.c b/backend.c
index d2b97db..2e6a377 100644
--- a/backend.c
+++ b/backend.c
@@ -62,6 +62,8 @@
int groupid = 0;
unsigned int thread_number = 0;
+unsigned int nr_segments = 0;
+unsigned int cur_segment = 0;
unsigned int stat_number = 0;
int temp_stall_ts;
unsigned long done_secs = 0;
@@ -75,7 +77,7 @@
static void sig_int(int sig)
{
- if (segments[0].threads) {
+ if (nr_segments) {
if (is_backend)
fio_server_got_signal(sig);
else {
diff --git a/fio.h b/fio.h
index 691976a..fffec00 100644
--- a/fio.h
+++ b/fio.h
@@ -470,6 +470,7 @@
struct thread_segment {
struct thread_data *threads;
int shm_id;
+ int nr_threads;
};
/*
@@ -522,6 +523,8 @@
extern bool exitall_on_terminate;
extern unsigned int thread_number;
extern unsigned int stat_number;
+extern unsigned int nr_segments;
+extern unsigned int cur_segment;
extern int groupid;
extern int output_format;
extern int append_terse_output;
@@ -552,6 +555,14 @@
extern struct thread_segment segments[REAL_MAX_SEG];
+static inline struct thread_data *tnumber_to_td(unsigned int tnumber)
+{
+ struct thread_segment *seg;
+
+ seg = &segments[tnumber / JOBS_PER_SEG];
+ return &seg->threads[tnumber & (JOBS_PER_SEG - 1)];
+}
+
static inline bool is_running_backend(void)
{
return is_backend || is_local_backend;
@@ -715,7 +726,7 @@
* Iterates all threads/processes within all the defined jobs
*/
#define for_each_td(td, i) \
- for ((i) = 0, (td) = &segments[0].threads[0]; (i) < (int) thread_number; (i)++, (td)++)
+ for ((i) = 0, (td) = &segments[0].threads[0]; (i) < (int) thread_number; (i)++, (td) = tnumber_to_td((i)))
#define for_each_file(td, f, i) \
if ((td)->files_index) \
for ((i) = 0, (f) = (td)->files[0]; \
diff --git a/gettime-thread.c b/gettime-thread.c
index 9b82e53..86c2e2e 100644
--- a/gettime-thread.c
+++ b/gettime-thread.c
@@ -58,7 +58,7 @@
* but I'm not sure what to use outside of a simple CPU nop to relax
* it - we don't want to lose precision.
*/
- while (segments[0].threads) {
+ while (nr_segments) {
fio_gtod_update();
nop;
}
diff --git a/init.c b/init.c
index 36b10ea..c344284 100644
--- a/init.c
+++ b/init.c
@@ -301,25 +301,34 @@
void free_threads_shm(void)
{
- if (segments[0].threads) {
- void *tp = segments[0].threads;
-#ifndef CONFIG_NO_SHM
- struct shmid_ds sbuf;
+ int i;
- segments[0].threads = NULL;
- shmdt(tp);
- shmctl(segments[0].shm_id, IPC_RMID, &sbuf);
- segments[0].shm_id = -1;
+ for (i = 0; i < nr_segments; i++) {
+ struct thread_segment *seg = &segments[i];
+
+ if (seg->threads) {
+ void *tp = seg->threads;
+#ifndef CONFIG_NO_SHM
+ struct shmid_ds sbuf;
+
+ seg->threads = NULL;
+ shmdt(tp);
+ shmctl(seg->shm_id, IPC_RMID, &sbuf);
+ seg->shm_id = -1;
#else
- segments[0].threads = NULL;
- free(tp);
+ seg->threads = NULL;
+ free(tp);
#endif
+ }
}
+
+ nr_segments = 0;
+ cur_segment = 0;
}
static void free_shm(void)
{
- if (segments[0].threads) {
+ if (nr_segments) {
flow_exit();
fio_debug_jobp = NULL;
fio_warned = NULL;
@@ -337,50 +346,31 @@
scleanup();
}
-/*
- * The thread area is shared between the main process and the job
- * threads/processes. So setup a shared memory segment that will hold
- * all the job info. We use the end of the region for keeping track of
- * open files across jobs, for file sharing.
- */
-static int setup_thread_area(void)
+static int add_thread_segment(void)
{
- struct thread_segment *seg = &segments[0];
+ struct thread_segment *seg = &segments[nr_segments];
+ size_t size = JOBS_PER_SEG * sizeof(struct thread_data);
int i;
- if (seg->threads)
- return 0;
+ if (nr_segments + 1 >= REAL_MAX_SEG)
+ return -1;
- /*
- * 1024 is too much on some machines, scale max_jobs if
- * we get a failure that looks like too large a shm segment
- */
- do {
- size_t size = max_jobs * sizeof(struct thread_data);
-
- size += 2 * sizeof(unsigned int);
+ size += 2 * sizeof(unsigned int);
#ifndef CONFIG_NO_SHM
- seg->shm_id = shmget(0, size, IPC_CREAT | 0600);
- if (seg->shm_id != -1)
- break;
- if (errno != EINVAL && errno != ENOMEM && errno != ENOSPC) {
+ seg->shm_id = shmget(0, size, IPC_CREAT | 0600);
+ if (seg->shm_id == -1) {
+ if (errno != EINVAL && errno != ENOMEM && errno != ENOSPC)
perror("shmget");
- break;
- }
+ return -1;
+ }
#else
- seg->threads = malloc(size);
- if (seg->threads)
- break;
+ seg->threads = malloc(size);
+ if (!seg->threads)
+ return -1;
#endif
- max_jobs >>= 1;
- } while (max_jobs);
-
#ifndef CONFIG_NO_SHM
- if (seg->shm_id == -1)
- return 1;
-
seg->threads = shmat(seg->shm_id, NULL, 0);
if (seg->threads == (void *) -1) {
perror("shmat");
@@ -390,19 +380,43 @@
shmctl(seg->shm_id, IPC_RMID, NULL);
#endif
- memset(seg->threads, 0, max_jobs * sizeof(struct thread_data));
- for (i = 0; i < max_jobs; i++)
+ nr_segments++;
+
+ memset(seg->threads, 0, JOBS_PER_SEG * sizeof(struct thread_data));
+ for (i = 0; i < JOBS_PER_SEG; i++)
DRD_IGNORE_VAR(seg->threads[i]);
- fio_debug_jobp = (unsigned int *)(seg->threads + max_jobs);
+ seg->nr_threads = 0;
+
+ /* Not first segment, we're done */
+ if (nr_segments != 1) {
+ cur_segment++;
+ return 0;
+ }
+
+ fio_debug_jobp = (unsigned int *)(seg->threads + JOBS_PER_SEG);
*fio_debug_jobp = -1;
fio_warned = fio_debug_jobp + 1;
*fio_warned = 0;
flow_init();
-
return 0;
}
+/*
+ * The thread areas are shared between the main process and the job
+ * threads/processes, and is split into chunks of JOBS_PER_SEG. If the current
+ * segment has no more room, add a new chunk.
+ */
+static int expand_thread_area(void)
+{
+ struct thread_segment *seg = &segments[cur_segment];
+
+ if (nr_segments && seg->nr_threads < JOBS_PER_SEG)
+ return 0;
+
+ return add_thread_segment();
+}
+
static void dump_print_option(struct print_option *p)
{
const char *delim;
@@ -471,11 +485,12 @@
static struct thread_data *get_new_job(bool global, struct thread_data *parent,
bool preserve_eo, const char *jobname)
{
+ struct thread_segment *seg;
struct thread_data *td;
if (global)
return &def_thread;
- if (setup_thread_area()) {
+ if (expand_thread_area()) {
log_err("error: failed to setup shm segment\n");
return NULL;
}
@@ -485,7 +500,9 @@
return NULL;
}
- td = &segments[0].threads[thread_number++];
+ seg = &segments[cur_segment];
+ td = &seg->threads[seg->nr_threads++];
+ thread_number++;
*td = *parent;
INIT_FLIST_HEAD(&td->opt_list);
@@ -536,6 +553,7 @@
free(td->o.name);
memset(td, 0, sizeof(*td));
+ segments[cur_segment].nr_threads--;
thread_number--;
}
diff --git a/libfio.c b/libfio.c
index 7348b16..6144a47 100644
--- a/libfio.c
+++ b/libfio.c
@@ -156,8 +156,13 @@
void reset_fio_state(void)
{
+ int i;
+
groupid = 0;
thread_number = 0;
+ cur_segment = 0;
+ for (i = 0; i < nr_segments; i++)
+ segments[i].nr_threads = 0;
stat_number = 0;
done_secs = 0;
}
diff --git a/server.c b/server.c
index c9b5c28..1b65297 100644
--- a/server.c
+++ b/server.c
@@ -950,7 +950,7 @@
return 0;
}
- td = &segments[0].threads[tnumber - 1];
+ td = tnumber_to_td(tnumber);
convert_thread_options_to_cpu(&td->o, &pdu->top);
send_update_job_reply(cmd->tag, 0);
return 0;
