mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-24 20:54:10 +08:00
ntb_perf: Improve thread handling to increase robustness
This commit accomplishes a few things: 1) Properly prevent multiple sets of threads from running at once using a mutex. Lots of race issues existed with the thread_cleanup. 2) The mutex allows us to ensure that threads are finished before tearing down the device or module. 3) Don't use kthread_stop when the threads can exit by themselves, as this is counter-indicated by the kthread_create documentation. Threads now wait for kthread_stop to occur. 4) Writing to the run file now blocks until the threads are complete. The test can then be safely interrupted by a SIGINT. Also, while I was at it: 5) debugfs_run_write shouldn't return 0 in the early check cases as this could cause debugfs_run_write to loop undesirably. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Acked-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
This commit is contained in:
Logan Gunthorpe
Jon Mason
parent
fd2ecd885b
commit
da573eaa3a
@ -58,6 +58,7 @@
|
||||
#include <linux/delay.h>
|
||||
#include <linux/sizes.h>
|
||||
#include <linux/ntb.h>
|
||||
#include <linux/mutex.h>
|
||||
|
||||
#define DRIVER_NAME "ntb_perf"
|
||||
#define DRIVER_DESCRIPTION "PCIe NTB Performance Measurement Tool"
|
||||
@ -121,6 +122,7 @@ struct pthr_ctx {
|
||||
int dma_prep_err;
|
||||
int src_idx;
|
||||
void *srcs[MAX_SRCS];
|
||||
wait_queue_head_t *wq;
|
||||
};
|
||||
|
||||
struct perf_ctx {
|
||||
@ -134,9 +136,11 @@ struct perf_ctx {
|
||||
struct dentry *debugfs_run;
|
||||
struct dentry *debugfs_threads;
|
||||
u8 perf_threads;
|
||||
bool run;
|
||||
/* mutex ensures only one set of threads run at once */
|
||||
struct mutex run_mutex;
|
||||
struct pthr_ctx pthr_ctx[MAX_THREADS];
|
||||
atomic_t tsync;
|
||||
atomic_t tdone;
|
||||
};
|
||||
|
||||
enum {
|
||||
@ -295,12 +299,18 @@ static int perf_move_data(struct pthr_ctx *pctx, char __iomem *dst, char *src,
|
||||
set_current_state(TASK_INTERRUPTIBLE);
|
||||
schedule_timeout(1);
|
||||
}
|
||||
|
||||
if (unlikely(kthread_should_stop()))
|
||||
break;
|
||||
}
|
||||
|
||||
if (use_dma) {
|
||||
pr_info("%s: All DMA descriptors submitted\n", current->comm);
|
||||
while (atomic_read(&pctx->dma_sync) != 0)
|
||||
while (atomic_read(&pctx->dma_sync) != 0) {
|
||||
if (kthread_should_stop())
|
||||
break;
|
||||
msleep(20);
|
||||
}
|
||||
}
|
||||
|
||||
kstop = ktime_get();
|
||||
@ -393,7 +403,10 @@ static int ntb_perf_thread(void *data)
|
||||
pctx->srcs[i] = NULL;
|
||||
}
|
||||
|
||||
return 0;
|
||||
atomic_inc(&perf->tdone);
|
||||
wake_up(pctx->wq);
|
||||
rc = 0;
|
||||
goto done;
|
||||
|
||||
err:
|
||||
for (i = 0; i < MAX_SRCS; i++) {
|
||||
@ -406,6 +419,16 @@ err:
|
||||
pctx->dma_chan = NULL;
|
||||
}
|
||||
|
||||
done:
|
||||
/* Wait until we are told to stop */
|
||||
for (;;) {
|
||||
set_current_state(TASK_INTERRUPTIBLE);
|
||||
if (kthread_should_stop())
|
||||
break;
|
||||
schedule();
|
||||
}
|
||||
__set_current_state(TASK_RUNNING);
|
||||
|
||||
return rc;
|
||||
}
|
||||
|
||||
@ -553,6 +576,7 @@ static ssize_t debugfs_run_read(struct file *filp, char __user *ubuf,
|
||||
struct perf_ctx *perf = filp->private_data;
|
||||
char *buf;
|
||||
ssize_t ret, out_offset;
|
||||
int running;
|
||||
|
||||
if (!perf)
|
||||
return 0;
|
||||
@ -560,7 +584,9 @@ static ssize_t debugfs_run_read(struct file *filp, char __user *ubuf,
|
||||
buf = kmalloc(64, GFP_KERNEL);
|
||||
if (!buf)
|
||||
return -ENOMEM;
|
||||
out_offset = snprintf(buf, 64, "%d\n", perf->run);
|
||||
|
||||
running = mutex_is_locked(&perf->run_mutex);
|
||||
out_offset = snprintf(buf, 64, "%d\n", running);
|
||||
ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
|
||||
kfree(buf);
|
||||
|
||||
@ -572,7 +598,6 @@ static void threads_cleanup(struct perf_ctx *perf)
|
||||
struct pthr_ctx *pctx;
|
||||
int i;
|
||||
|
||||
perf->run = false;
|
||||
for (i = 0; i < MAX_THREADS; i++) {
|
||||
pctx = &perf->pthr_ctx[i];
|
||||
if (pctx->thread) {
|
||||
@ -587,65 +612,66 @@ static ssize_t debugfs_run_write(struct file *filp, const char __user *ubuf,
|
||||
{
|
||||
struct perf_ctx *perf = filp->private_data;
|
||||
int node, i;
|
||||
DECLARE_WAIT_QUEUE_HEAD(wq);
|
||||
|
||||
if (!perf->link_is_up)
|
||||
return 0;
|
||||
return -ENOLINK;
|
||||
|
||||
if (perf->perf_threads == 0)
|
||||
return 0;
|
||||
return -EINVAL;
|
||||
|
||||
if (atomic_read(&perf->tsync) == 0)
|
||||
perf->run = false;
|
||||
|
||||
if (perf->run)
|
||||
threads_cleanup(perf);
|
||||
else {
|
||||
perf->run = true;
|
||||
|
||||
if (perf->perf_threads > MAX_THREADS) {
|
||||
perf->perf_threads = MAX_THREADS;
|
||||
pr_info("Reset total threads to: %u\n", MAX_THREADS);
|
||||
}
|
||||
|
||||
/* no greater than 1M */
|
||||
if (seg_order > MAX_SEG_ORDER) {
|
||||
seg_order = MAX_SEG_ORDER;
|
||||
pr_info("Fix seg_order to %u\n", seg_order);
|
||||
}
|
||||
|
||||
if (run_order < seg_order) {
|
||||
run_order = seg_order;
|
||||
pr_info("Fix run_order to %u\n", run_order);
|
||||
}
|
||||
|
||||
node = dev_to_node(&perf->ntb->pdev->dev);
|
||||
/* launch kernel thread */
|
||||
for (i = 0; i < perf->perf_threads; i++) {
|
||||
struct pthr_ctx *pctx;
|
||||
|
||||
pctx = &perf->pthr_ctx[i];
|
||||
atomic_set(&pctx->dma_sync, 0);
|
||||
pctx->perf = perf;
|
||||
pctx->thread =
|
||||
kthread_create_on_node(ntb_perf_thread,
|
||||
(void *)pctx,
|
||||
node, "ntb_perf %d", i);
|
||||
if (IS_ERR(pctx->thread)) {
|
||||
pctx->thread = NULL;
|
||||
goto err;
|
||||
} else
|
||||
wake_up_process(pctx->thread);
|
||||
|
||||
if (perf->run == false)
|
||||
return -ENXIO;
|
||||
}
|
||||
if (!mutex_trylock(&perf->run_mutex))
|
||||
return -EBUSY;
|
||||
|
||||
if (perf->perf_threads > MAX_THREADS) {
|
||||
perf->perf_threads = MAX_THREADS;
|
||||
pr_info("Reset total threads to: %u\n", MAX_THREADS);
|
||||
}
|
||||
|
||||
/* no greater than 1M */
|
||||
if (seg_order > MAX_SEG_ORDER) {
|
||||
seg_order = MAX_SEG_ORDER;
|
||||
pr_info("Fix seg_order to %u\n", seg_order);
|
||||
}
|
||||
|
||||
if (run_order < seg_order) {
|
||||
run_order = seg_order;
|
||||
pr_info("Fix run_order to %u\n", run_order);
|
||||
}
|
||||
|
||||
node = dev_to_node(&perf->ntb->pdev->dev);
|
||||
atomic_set(&perf->tdone, 0);
|
||||
|
||||
/* launch kernel thread */
|
||||
for (i = 0; i < perf->perf_threads; i++) {
|
||||
struct pthr_ctx *pctx;
|
||||
|
||||
pctx = &perf->pthr_ctx[i];
|
||||
atomic_set(&pctx->dma_sync, 0);
|
||||
pctx->perf = perf;
|
||||
pctx->wq = &wq;
|
||||
pctx->thread =
|
||||
kthread_create_on_node(ntb_perf_thread,
|
||||
(void *)pctx,
|
||||
node, "ntb_perf %d", i);
|
||||
if (IS_ERR(pctx->thread)) {
|
||||
pctx->thread = NULL;
|
||||
goto err;
|
||||
} else {
|
||||
wake_up_process(pctx->thread);
|
||||
}
|
||||
}
|
||||
|
||||
wait_event_interruptible(wq,
|
||||
atomic_read(&perf->tdone) == perf->perf_threads);
|
||||
|
||||
threads_cleanup(perf);
|
||||
mutex_unlock(&perf->run_mutex);
|
||||
return count;
|
||||
|
||||
err:
|
||||
threads_cleanup(perf);
|
||||
mutex_unlock(&perf->run_mutex);
|
||||
return -ENXIO;
|
||||
}
|
||||
|
||||
@ -713,7 +739,7 @@ static int perf_probe(struct ntb_client *client, struct ntb_dev *ntb)
|
||||
perf->ntb = ntb;
|
||||
perf->perf_threads = 1;
|
||||
atomic_set(&perf->tsync, 0);
|
||||
perf->run = false;
|
||||
mutex_init(&perf->run_mutex);
|
||||
spin_lock_init(&perf->db_lock);
|
||||
perf_setup_mw(ntb, perf);
|
||||
INIT_DELAYED_WORK(&perf->link_work, perf_link_work);
|
||||
@ -748,6 +774,8 @@ static void perf_remove(struct ntb_client *client, struct ntb_dev *ntb)
|
||||
|
||||
dev_dbg(&perf->ntb->dev, "%s called\n", __func__);
|
||||
|
||||
mutex_lock(&perf->run_mutex);
|
||||
|
||||
cancel_delayed_work_sync(&perf->link_work);
|
||||
cancel_work_sync(&perf->link_cleanup);
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user