On Thu, May 07, 2020 at 04:10:55PM +0800, Frankie Chang wrote: > From: "Frankie.Chang" <[email protected]> > > Record start/end timestamp for binder transaction. > When transaction is completed or transaction is free, > it would be checked if transaction latency over threshold (2 sec), > if yes, printing related information for tracing.
Shouldn't that "printing" go to the trace buffer and not to the kernel information log? > > /* Implement details */ > - Add latency tracer module to monitor slow transaction. > The trace_binder_free_transaction would not be enabled > by default. Monitoring which transaction is too slow to > cause some of exceptions is important. So we hook the > tracepoint to call the monitor function. > > Signed-off-by: Frankie.Chang <[email protected]> > --- > drivers/android/Kconfig | 8 +++ > drivers/android/Makefile | 1 + > drivers/android/binder.c | 2 + > drivers/android/binder_internal.h | 13 ++++ > drivers/android/binder_latency_tracer.c | 105 > +++++++++++++++++++++++++++++++ > drivers/android/binder_trace.h | 26 +++++++- > 6 files changed, 152 insertions(+), 3 deletions(-) > create mode 100644 drivers/android/binder_latency_tracer.c > > Change from v4: > split up into patch series. > > Change from v3: > use tracepoints for binder_update_info and print_binder_transaction_ext, > instead of custom registration functions. > > Change from v2: > create transaction latency module to monitor slow transaction. > > Change from v1: > first patchset. > > diff --git a/drivers/android/Kconfig b/drivers/android/Kconfig > index 6fdf2ab..7ba80eb 100644 > --- a/drivers/android/Kconfig > +++ b/drivers/android/Kconfig > @@ -54,6 +54,14 @@ config ANDROID_BINDER_IPC_SELFTEST > exhaustively with combinations of various buffer sizes and > alignments. > > +config BINDER_USER_TRACKING > + bool "Android Binder transaction tracking" > + help > + Used for track abnormal binder transaction which is over 2 seconds, > + when the transaction is done or be free, this transaction would be > + checked whether it executed overtime. > + If yes, printing out the detail info about it. > + > endif # if ANDROID > > endmenu > diff --git a/drivers/android/Makefile b/drivers/android/Makefile > index c9d3d0c9..552e8ac 100644 > --- a/drivers/android/Makefile > +++ b/drivers/android/Makefile > @@ -4,3 +4,4 @@ ccflags-y += -I$(src) # needed for trace > events > obj-$(CONFIG_ANDROID_BINDERFS) += binderfs.o > obj-$(CONFIG_ANDROID_BINDER_IPC) += binder.o binder_alloc.o > obj-$(CONFIG_ANDROID_BINDER_IPC_SELFTEST) += binder_alloc_selftest.o > +obj-$(CONFIG_BINDER_USER_TRACKING) += binder_latency_tracer.o > diff --git a/drivers/android/binder.c b/drivers/android/binder.c > index 4c3dd98..b89d75a 100644 > --- a/drivers/android/binder.c > +++ b/drivers/android/binder.c > @@ -2657,6 +2657,7 @@ static void binder_transaction(struct binder_proc *proc, > return_error_line = __LINE__; > goto err_alloc_t_failed; > } > + trace_binder_update_info(t, e); > INIT_LIST_HEAD(&t->fd_fixups); > binder_stats_created(BINDER_STAT_TRANSACTION); > spin_lock_init(&t->lock); > @@ -5145,6 +5146,7 @@ static void print_binder_transaction_ilocked(struct > seq_file *m, > t->to_thread ? t->to_thread->pid : 0, > t->code, t->flags, t->priority, t->need_reply); > spin_unlock(&t->lock); > + trace_print_binder_transaction_ext(m, t); > > if (proc != to_proc) { > /* > diff --git a/drivers/android/binder_internal.h > b/drivers/android/binder_internal.h > index ed61b3e..24d7beb 100644 > --- a/drivers/android/binder_internal.h > +++ b/drivers/android/binder_internal.h > @@ -12,6 +12,11 @@ > #include <linux/types.h> > #include <linux/uidgid.h> > > +#ifdef CONFIG_BINDER_USER_TRACKING > +#include <linux/rtc.h> > +#include <linux/time.h> > +#endif > + > struct binder_context { > struct binder_node *binder_context_mgr_node; > struct mutex context_mgr_node_lock; > @@ -131,6 +136,10 @@ struct binder_transaction_log_entry { > uint32_t return_error; > uint32_t return_error_param; > char context_name[BINDERFS_MAX_NAME + 1]; > +#ifdef CONFIG_BINDER_USER_TRACKING > + struct timespec timestamp; > + struct timeval tv; > +#endif > }; > > struct binder_transaction_log { > @@ -520,6 +529,10 @@ struct binder_transaction { > * during thread teardown > */ > spinlock_t lock; > +#ifdef CONFIG_BINDER_USER_TRACKING > + struct timespec timestamp; > + struct timeval tv; > +#endif > }; > > /** > diff --git a/drivers/android/binder_latency_tracer.c > b/drivers/android/binder_latency_tracer.c > new file mode 100644 > index 0000000..45c14fb > --- /dev/null > +++ b/drivers/android/binder_latency_tracer.c > @@ -0,0 +1,105 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2019 MediaTek Inc. > + */ > + > +#include <linux/module.h> > +#include <uapi/linux/android/binder.h> > +#include "binder_alloc.h" > +#include "binder_internal.h" > +#include "binder_trace.h" > + > +/* > + * probe_binder_free_transaction - Output info of a delay transaction > + * @t: pointer to the over-time transaction > + */ > +void probe_binder_free_transaction(void *ignore, struct binder_transaction > *t) > +{ > + struct rtc_time tm; > + struct timespec *startime; > + struct timespec cur, sub_t; > + > + ktime_get_ts(&cur); > + startime = &t->timestamp; > + sub_t = timespec_sub(cur, *startime); > + > + /* if transaction time is over than 2 sec, > + * show timeout warning log. > + */ > + if (sub_t.tv_sec < 2) > + return; Why is 2 seconds somehow "magic" here? > + > + rtc_time_to_tm(t->tv.tv_sec, &tm); > + > + spin_lock(&t->lock); > + pr_info_ratelimited("%d: from %d:%d to %d:%d", > + t->debug_id, > + t->from ? t->from->proc->pid : 0, > + t->from ? t->from->pid : 0, > + t->to_proc ? t->to_proc->pid : 0, > + t->to_thread ? t->to_thread->pid : 0); > + spin_unlock(&t->lock); Why is the lock ok to give up here and not after the next call? > + > + pr_info_ratelimited(" total %u.%03ld s code %u start %lu.%03ld android > %d-%02d-%02d %02d:%02d:%02d.%03lu\n", > + (unsigned int)sub_t.tv_sec, > + (sub_t.tv_nsec / NSEC_PER_MSEC), > + t->code, > + (unsigned long)startime->tv_sec, > + (startime->tv_nsec / NSEC_PER_MSEC), > + (tm.tm_year + 1900), (tm.tm_mon + 1), tm.tm_mday, > + tm.tm_hour, tm.tm_min, tm.tm_sec, > + (unsigned long)(t->tv.tv_usec / USEC_PER_MSEC)); > +} > + > +static void probe_binder_update_info(void *ignore, struct binder_transaction > *t, > + struct binder_transaction_log_entry *e) > +{ > + ktime_get_ts(&e->timestamp); > + do_gettimeofday(&e->tv); > + e->tv.tv_sec -= (sys_tz.tz_minuteswest * 60); > + memcpy(&t->timestamp, &e->timestamp, sizeof(struct timespec)); > + memcpy(&t->tv, &e->tv, sizeof(struct timeval)); No locking needed?
