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[SMAGENT-2066] Control driver printing when in interrupt context #1522

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Merged
merged 1 commit into from
Oct 22, 2019
Merged

[SMAGENT-2066] Control driver printing when in interrupt context #1522

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37 changes: 25 additions & 12 deletions driver/main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1396,29 +1396,35 @@ static enum ppm_event_type parse_socketcall(struct event_filler_arguments *fille
}
#endif /* _HAS_SOCKETCALL */

static inline void record_drop_e(struct ppm_consumer_t *consumer, struct timespec *ts)
static inline void record_drop_e(struct ppm_consumer_t *consumer,
struct timespec *ts,
enum syscall_flags drop_flags)
{
struct event_data_t event_data = {0};

if (record_event_consumer(consumer, PPME_DROP_E, UF_NEVER_DROP, ts, &event_data) == 0) {
consumer->need_to_insert_drop_e = 1;
} else {
if (consumer->need_to_insert_drop_e == 1)
if (consumer->need_to_insert_drop_e == 1 && !(drop_flags & UF_ATOMIC)) {
pr_err("drop enter event delayed insert\n");
}

consumer->need_to_insert_drop_e = 0;
}
}

static inline void record_drop_x(struct ppm_consumer_t *consumer, struct timespec *ts)
static inline void record_drop_x(struct ppm_consumer_t *consumer,
struct timespec *ts,
enum syscall_flags drop_flags)
{
struct event_data_t event_data = {0};

if (record_event_consumer(consumer, PPME_DROP_X, UF_NEVER_DROP, ts, &event_data) == 0) {
consumer->need_to_insert_drop_x = 1;
} else {
if (consumer->need_to_insert_drop_x == 1)
if (consumer->need_to_insert_drop_x == 1 && !(drop_flags & UF_ATOMIC)) {
pr_err("drop exit event delayed insert\n");
}

consumer->need_to_insert_drop_x = 0;
}
Expand Down Expand Up @@ -1515,15 +1521,15 @@ static inline int drop_event(struct ppm_consumer_t *consumer,
if (ts->tv_nsec >= consumer->sampling_interval) {
if (consumer->is_dropping == 0) {
consumer->is_dropping = 1;
record_drop_e(consumer, ts);
record_drop_e(consumer, ts, drop_flags);
}

return 1;
}

if (consumer->is_dropping == 1) {
consumer->is_dropping = 0;
record_drop_x(consumer, ts);
record_drop_x(consumer, ts, drop_flags);
}
}

Expand Down Expand Up @@ -1575,12 +1581,15 @@ static int record_event_consumer(struct ppm_consumer_t *consumer,

if (event_type != PPME_DROP_E && event_type != PPME_DROP_X) {
if (consumer->need_to_insert_drop_e == 1)
record_drop_e(consumer, ts);
record_drop_e(consumer, ts, drop_flags);
else if (consumer->need_to_insert_drop_x == 1)
record_drop_x(consumer, ts);
record_drop_x(consumer, ts, drop_flags);

if (drop_event(consumer, event_type, drop_flags, ts,
event_datap->event_info.syscall_data.regs))
if (drop_event(consumer,
event_type,
drop_flags,
ts,
event_datap->event_info.syscall_data.regs))
return res;
}

Expand Down Expand Up @@ -1852,7 +1861,7 @@ static int record_event_consumer(struct ppm_consumer_t *consumer,
}
}

if (ts->tv_sec > ring->last_print_time.tv_sec + 1) {
if (ts->tv_sec > ring->last_print_time.tv_sec + 1 && !(drop_flags & UF_ATOMIC)) {
vpr_info("consumer:%p CPU:%d, use:%d%%, ev:%llu, dr_buf:%llu, dr_pf:%llu, pr:%llu, cs:%llu\n",
consumer->consumer_id,
smp_processor_id(),
Expand Down Expand Up @@ -2087,7 +2096,11 @@ TRACEPOINT_PROBE(sched_switch_probe, bool preempt, struct task_struct *prev, str
event_data.event_info.context_data.sched_prev = prev;
event_data.event_info.context_data.sched_next = next;

record_event_all_consumers(PPME_SCHEDSWITCH_6_E, UF_USED, &event_data);
/*
* Need to indicate ATOMIC (i.e. interrupt) context to avoid the event
* handler calling printk() and potentially deadlocking the system.
*/
record_event_all_consumers(PPME_SCHEDSWITCH_6_E, UF_USED | UF_ATOMIC, &event_data);
}
#endif

Expand Down
1 change: 1 addition & 0 deletions driver/ppm_events_public.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1531,6 +1531,7 @@ enum syscall_flags {
UF_NEVER_DROP = (1 << 1),
UF_ALWAYS_DROP = (1 << 2),
UF_SIMPLEDRIVER_KEEP = (1 << 3),
UF_ATOMIC = (1 << 4), ///< The handler should not block (interrupt context)
};

struct syscall_evt_pair {
Expand Down