Module Name: src
Committed By: ryo
Date: Fri Dec 16 07:59:42 UTC 2022
Modified Files:
src/sys/dev/tprof: tprof.c
Log Message:
- Add support select(2)/poll(2) on /dev/tprof.
- Changed sampling buffer switching frequency (which is the frequency of
tprof_worker()
calls and also the maximum block time of read(2) of /dev/tprof) from 1sec to
125ms.
This improve tprof top responsiveness.
- The maximum number of sampling buffers is now adjusted according to the
number of CPUs.
Previously it was fixed at 100 and was insufficient if ncpu was greater than
this.
The maximum number of samples per second per CPU is calculated by
"TPROF_MAX_SAMPLES_PER_BUF * (HZ of tprof_worker)".
Therefore, currently, 10000 * (1000/125) = 80000 maximum samplings per CPU.
The actual value will vary slightly from this due to tprof_worker and read(2)
timing.
This value may need to be adjusted more in the future.
To generate a diff of this commit:
cvs rdiff -u -r1.20 -r1.21 src/sys/dev/tprof/tprof.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/tprof/tprof.c
diff -u src/sys/dev/tprof/tprof.c:1.20 src/sys/dev/tprof/tprof.c:1.21
--- src/sys/dev/tprof/tprof.c:1.20 Sun Dec 11 01:36:49 2022
+++ src/sys/dev/tprof/tprof.c Fri Dec 16 07:59:42 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: tprof.c,v 1.20 2022/12/11 01:36:49 chs Exp $ */
+/* $NetBSD: tprof.c,v 1.21 2022/12/16 07:59:42 ryo Exp $ */
/*-
* Copyright (c)2008,2009,2010 YAMAMOTO Takashi,
@@ -27,7 +27,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tprof.c,v 1.20 2022/12/11 01:36:49 chs Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tprof.c,v 1.21 2022/12/16 07:59:42 ryo Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -39,8 +39,10 @@ __KERNEL_RCSID(0, "$NetBSD: tprof.c,v 1.
#include <sys/kmem.h>
#include <sys/module.h>
#include <sys/percpu.h>
+#include <sys/poll.h>
#include <sys/proc.h>
#include <sys/queue.h>
+#include <sys/select.h>
#include <sys/workqueue.h>
#include <sys/xcall.h>
@@ -78,9 +80,7 @@ typedef struct tprof_buf {
} tprof_buf_t;
#define TPROF_BUF_BYTESIZE(sz) \
(sizeof(tprof_buf_t) + (sz) * sizeof(tprof_sample_t))
-#define TPROF_MAX_SAMPLES_PER_BUF (TPROF_HZ * 2)
-
-#define TPROF_MAX_BUF 100
+#define TPROF_MAX_SAMPLES_PER_BUF TPROF_HZ
typedef struct {
tprof_buf_t *c_buf;
@@ -111,6 +111,7 @@ static u_int tprof_nbuf_on_list; /* L: #
static struct workqueue *tprof_wq;
static struct percpu *tprof_cpus __read_mostly; /* tprof_cpu_t * */
static u_int tprof_samples_per_buf;
+static u_int tprof_max_buf;
tprof_backend_t *tprof_backend; /* S: */
static LIST_HEAD(, tprof_backend) tprof_backends =
@@ -122,6 +123,7 @@ static off_t tprof_reader_offset; /* R:
static kmutex_t tprof_startstop_lock;
static kcondvar_t tprof_cv; /* L: */
+static struct selinfo tprof_selp; /* L: */
static struct tprof_stat tprof_stat; /* L: */
@@ -229,13 +231,14 @@ tprof_worker(struct work *wk, void *dumm
}
if (buf->b_used == 0) {
tprof_stat.ts_emptybuf++;
- } else if (tprof_nbuf_on_list < TPROF_MAX_BUF) {
+ } else if (tprof_nbuf_on_list < tprof_max_buf) {
tprof_stat.ts_sample += buf->b_used;
tprof_stat.ts_overflow += buf->b_overflow;
tprof_stat.ts_buf++;
STAILQ_INSERT_TAIL(&tprof_list, buf, b_list);
tprof_nbuf_on_list++;
buf = NULL;
+ selnotify(&tprof_selp, 0, NOTE_SUBMIT);
cv_broadcast(&tprof_reader_cv);
} else {
tprof_stat.ts_dropbuf_sample += buf->b_used;
@@ -246,7 +249,7 @@ tprof_worker(struct work *wk, void *dumm
tprof_buf_free(buf);
}
if (!shouldstop) {
- callout_schedule(&c->c_callout, hz);
+ callout_schedule(&c->c_callout, hz / 8);
}
}
@@ -364,6 +367,7 @@ tprof_start(tprof_countermask_t runmask)
}
tprof_samples_per_buf = TPROF_MAX_SAMPLES_PER_BUF;
+ tprof_max_buf = ncpu * 3;
error = workqueue_create(&tprof_wq, "tprofmv", tprof_worker,
NULL, PRI_NONE, IPL_SOFTCLOCK, WQ_MPSAFE | WQ_PERCPU);
if (error != 0) {
@@ -860,12 +864,89 @@ tprof_close(dev_t dev, int flags, int ty
}
static int
+tprof_poll(dev_t dev, int events, struct lwp *l)
+{
+ int revents;
+
+ revents = events & (POLLIN | POLLRDNORM);
+ if (revents == 0)
+ return 0;
+
+ mutex_enter(&tprof_lock);
+ if (STAILQ_EMPTY(&tprof_list)) {
+ revents = 0;
+ selrecord(l, &tprof_selp);
+ }
+ mutex_exit(&tprof_lock);
+
+ return revents;
+}
+
+static void
+filt_tprof_read_detach(struct knote *kn)
+{
+ mutex_spin_enter(&tprof_lock);
+ selremove_knote(&tprof_selp, kn);
+ mutex_spin_exit(&tprof_lock);
+}
+
+static int
+filt_tprof_read_event(struct knote *kn, long hint)
+{
+ int rv = 0;
+
+ if ((hint & NOTE_SUBMIT) == 0)
+ mutex_spin_enter(&tprof_lock);
+
+ if (!STAILQ_EMPTY(&tprof_list)) {
+ tprof_buf_t *buf;
+ int64_t n = 0;
+
+ STAILQ_FOREACH(buf, &tprof_list, b_list) {
+ n += buf->b_used;
+ }
+ kn->kn_data = n * sizeof(tprof_sample_t);
+
+ rv = 1;
+ }
+
+ if ((hint & NOTE_SUBMIT) == 0)
+ mutex_spin_exit(&tprof_lock);
+
+ return rv;
+}
+
+static const struct filterops tprof_read_filtops = {
+ .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
+ .f_attach = NULL,
+ .f_detach = filt_tprof_read_detach,
+ .f_event = filt_tprof_read_event,
+};
+
+static int
+tprof_kqfilter(dev_t dev, struct knote *kn)
+{
+ switch (kn->kn_filter) {
+ case EVFILT_READ:
+ kn->kn_fop = &tprof_read_filtops;
+ mutex_spin_enter(&tprof_lock);
+ selrecord_knote(&tprof_selp, kn);
+ mutex_spin_exit(&tprof_lock);
+ break;
+ default:
+ return EINVAL;
+ }
+
+ return 0;
+}
+
+static int
tprof_read(dev_t dev, struct uio *uio, int flags)
{
tprof_buf_t *buf;
size_t bytes;
size_t resid;
- size_t done;
+ size_t done = 0;
int error = 0;
KASSERT(minor(dev) == 0);
@@ -877,7 +958,7 @@ tprof_read(dev_t dev, struct uio *uio, i
mutex_enter(&tprof_lock);
buf = STAILQ_FIRST(&tprof_list);
if (buf == NULL) {
- if (tprof_nworker == 0) {
+ if (tprof_nworker == 0 || done != 0) {
mutex_exit(&tprof_lock);
error = 0;
break;
@@ -988,9 +1069,9 @@ const struct cdevsw tprof_cdevsw = {
.d_ioctl = tprof_ioctl,
.d_stop = nostop,
.d_tty = notty,
- .d_poll = nopoll,
+ .d_poll = tprof_poll,
.d_mmap = nommap,
- .d_kqfilter = nokqfilter,
+ .d_kqfilter = tprof_kqfilter,
.d_discard = nodiscard,
.d_flag = D_OTHER | D_MPSAFE
};
@@ -1034,6 +1115,7 @@ tprof_driver_init(void)
mutex_init(&tprof_lock, MUTEX_DEFAULT, IPL_NONE);
mutex_init(&tprof_reader_lock, MUTEX_DEFAULT, IPL_NONE);
mutex_init(&tprof_startstop_lock, MUTEX_DEFAULT, IPL_NONE);
+ selinit(&tprof_selp);
cv_init(&tprof_cv, "tprof");
cv_init(&tprof_reader_cv, "tprof_rd");
STAILQ_INIT(&tprof_list);
@@ -1049,6 +1131,7 @@ tprof_driver_fini(void)
mutex_destroy(&tprof_lock);
mutex_destroy(&tprof_reader_lock);
mutex_destroy(&tprof_startstop_lock);
+ seldestroy(&tprof_selp);
cv_destroy(&tprof_cv);
cv_destroy(&tprof_reader_cv);
}
