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authorLukas Larsson <[email protected]>2014-09-12 16:38:00 +0200
committerLukas Larsson <[email protected]>2016-02-02 10:45:21 +0100
commit664ed2a6fd2b324bb6b56db3d3eca853cfda8f61 (patch)
tree286743a4b1f794948329961e7f5879b5f54f54a5 /erts/emulator/sys/common
parenteea5f896780e07f7ca76685061d01e7be5a7abaa (diff)
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erts: Add microstate accounting
Microstate accounting is a way to track which state the different threads within ERTS are in. The main usage area is to pin point performance bottlenecks by checking which states the threads are in and then from there figuring out why and where to optimize. Since checking whether microstate accounting is on or off is relatively expensive if done in a short loop only a few of the states are enabled by default and more states can be enabled through configure. I've done some benchmarking and the overhead with it turned off is not noticible and with it on it is a fraction of a percent. If you enable the extra states, depending on the benchmark, the ovehead when turned off is about 1% and when turned on somewhere inbetween 5-15%. OTP-12345
Diffstat (limited to 'erts/emulator/sys/common')
-rw-r--r--erts/emulator/sys/common/erl_poll.c36
1 files changed, 28 insertions, 8 deletions
diff --git a/erts/emulator/sys/common/erl_poll.c b/erts/emulator/sys/common/erl_poll.c
index 21fa214364..36ee94111c 100644
--- a/erts/emulator/sys/common/erl_poll.c
+++ b/erts/emulator/sys/common/erl_poll.c
@@ -74,6 +74,7 @@
#include "erl_thr_progress.h"
#include "erl_driver.h"
#include "erl_alloc.h"
+#include "erl_msacc.h"
#if !defined(ERTS_POLL_USE_EPOLL) \
&& !defined(ERTS_POLL_USE_DEVPOLL) \
@@ -2238,6 +2239,7 @@ static ERTS_INLINE int
check_fd_events(ErtsPollSet ps, ErtsMonotonicTime timeout_time, int max_res)
{
int res;
+ ERTS_MSACC_PUSH_STATE_M();
if (erts_smp_atomic_read_nob(&ps->no_of_user_fds) == 0
&& timeout_time == ERTS_POLL_NO_TIMEOUT) {
/* Nothing to poll and zero timeout; done... */
@@ -2259,6 +2261,7 @@ check_fd_events(ErtsPollSet ps, ErtsMonotonicTime timeout_time, int max_res)
#ifdef ERTS_SMP
erts_thr_progress_prepare_wait(NULL);
#endif
+ ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_SLEEP);
timerfd_set(ps, &its);
res = epoll_wait(ps->kp_fd, ps->res_events, max_res, -1);
res = timerfd_clear(ps, res, max_res);
@@ -2268,10 +2271,12 @@ check_fd_events(ErtsPollSet ps, ErtsMonotonicTime timeout_time, int max_res)
}
#else /* !ERTS_POLL_USE_TIMERFD */
timeout = (int) get_timeout(ps, 1000, timeout_time);
+ if (timeout) {
#ifdef ERTS_SMP
- if (timeout)
erts_thr_progress_prepare_wait(NULL);
#endif
+ ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_SLEEP);
+ }
res = epoll_wait(ps->kp_fd, ps->res_events, max_res, timeout);
#endif /* !ERTS_POLL_USE_TIMERFD */
#elif ERTS_POLL_USE_KQUEUE /* --- kqueue ------------------------------ */
@@ -2279,10 +2284,12 @@ check_fd_events(ErtsPollSet ps, ErtsMonotonicTime timeout_time, int max_res)
if (max_res > ps->res_events_len)
grow_res_events(ps, max_res);
timeout = get_timeout_timespec(ps, &ts, timeout_time);
+ if (timeout) {
#ifdef ERTS_SMP
- if (timeout)
erts_thr_progress_prepare_wait(NULL);
#endif
+ ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_SLEEP);
+ }
res = kevent(ps->kp_fd, NULL, 0, ps->res_events, max_res, &ts);
#endif /* ----------------------------------------- */
}
@@ -2306,26 +2313,33 @@ check_fd_events(ErtsPollSet ps, ErtsMonotonicTime timeout_time, int max_res)
if (poll_res.dp_nfds > ps->res_events_len)
grow_res_events(ps, poll_res.dp_nfds);
poll_res.dp_fds = ps->res_events;
+ if (timeout) {
#ifdef ERTS_SMP
- if (timeout)
erts_thr_progress_prepare_wait(NULL);
#endif
+ ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_SLEEP);
+ }
poll_res.dp_timeout = timeout;
res = ioctl(ps->kp_fd, DP_POLL, &poll_res);
#elif ERTS_POLL_USE_POLL && defined(HAVE_PPOLL) /* --- ppoll ---------------- */
struct timespec ts;
timeout = get_timeout_timespec(ps, &ts, timeout_time);
+ if (timeout) {
#ifdef ERTS_SMP
- if (timeout)
erts_thr_progress_prepare_wait(NULL);
#endif
+ ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_SLEEP);
+ }
res = ppoll(ps->poll_fds, ps->no_poll_fds, &ts, NULL);
#elif ERTS_POLL_USE_POLL /* --- poll --------------------------------- */
timeout = (int) get_timeout(ps, 1000, timeout_time);
+
+ if (timeout) {
#ifdef ERTS_SMP
- if (timeout)
erts_thr_progress_prepare_wait(NULL);
#endif
+ ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_SLEEP);
+ }
res = poll(ps->poll_fds, ps->no_poll_fds, timeout);
#elif ERTS_POLL_USE_SELECT /* --- select ------------------------------ */
SysTimeval to;
@@ -2334,18 +2348,22 @@ check_fd_events(ErtsPollSet ps, ErtsMonotonicTime timeout_time, int max_res)
ERTS_FD_COPY(&ps->input_fds, &ps->res_input_fds);
ERTS_FD_COPY(&ps->output_fds, &ps->res_output_fds);
+ if (timeout) {
#ifdef ERTS_SMP
- if (timeout)
erts_thr_progress_prepare_wait(NULL);
#endif
+ ERTS_MSACC_SET_STATE_CACHED_M(ERTS_MSACC_STATE_SLEEP);
+ }
res = ERTS_SELECT(ps->max_fd + 1,
&ps->res_input_fds,
&ps->res_output_fds,
NULL,
&to);
#ifdef ERTS_SMP
- if (timeout)
+ if (timeout) {
erts_thr_progress_finalize_wait(NULL);
+ ERTS_MSACC_POP_STATE_M();
+ }
if (res < 0
&& errno == EBADF
&& ERTS_POLLSET_HAVE_UPDATE_REQUESTS(ps)) {
@@ -2380,10 +2398,12 @@ check_fd_events(ErtsPollSet ps, ErtsMonotonicTime timeout_time, int max_res)
return res;
#endif /* ----------------------------------------- */
}
+ if (timeout) {
#ifdef ERTS_SMP
- if (timeout)
erts_thr_progress_finalize_wait(NULL);
#endif
+ ERTS_MSACC_POP_STATE_M();
+ }
return res;
}
}