| Message ID | 20190315083754.27532-9-tstoyanov@vmware.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | trace-cmd: Timetamps sync between host and guest machines, relying on vsock events. | expand |
On Fri, Mar 15, 2019 at 10:38 AM Tzvetomir Stoyanov <tstoyanov@vmware.com> wrote: > > The TRACECMD_OPTION_TIME_SHIFT is used when synchronizing trace time stamps between > two trace.dat files. It contains multiple long long (time, offset) pairs, describing > time stamps _offset_, measured in the given local _time_. The content of the option > buffer is: > first 4 bytes - integer, count of timestamp offsets > long long array of size _count_, local time in which the offset is measured > long long array of size _count_, offset of the time stamps > > Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com> > --- > include/trace-cmd/trace-cmd.h | 1 + > lib/trace-cmd/trace-input.c | 119 +++++++++++++++++++++++++++++++++- > 2 files changed, 118 insertions(+), 2 deletions(-) > > diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h > index f7c043a..5552396 100644 > --- a/include/trace-cmd/trace-cmd.h > +++ b/include/trace-cmd/trace-cmd.h > @@ -82,6 +82,7 @@ enum { > TRACECMD_OPTION_HOOK, > TRACECMD_OPTION_OFFSET, > TRACECMD_OPTION_CPUCOUNT, > + TRACECMD_OPTION_TIME_SHIFT, > }; > > enum { > diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c > index 0a6e820..714f01c 100644 > --- a/lib/trace-cmd/trace-input.c > +++ b/lib/trace-cmd/trace-input.c > @@ -75,6 +75,11 @@ struct input_buffer_instance { > size_t offset; > }; > > +struct ts_offset_corr { > + long long time; > + long long offset; > +}; ts_offset_corr is not a particularly descriptive name imo. Wdyt about ts_offset_sample? > + > struct tracecmd_input { > struct tep_handle *pevent; > struct tep_plugin_list *plugin_list; > @@ -92,6 +97,8 @@ struct tracecmd_input { > bool use_pipe; > struct cpu_data *cpu_data; > long long ts_offset; > + int ts_corr_count; > + struct ts_offset_corr *ts_corr; > double ts2secs; > char * cpustats; > char * uname; > @@ -1028,6 +1035,68 @@ static void free_next(struct tracecmd_input *handle, int cpu) > free_record(record); > } > > +static inline unsigned long long > +timestamp_correction_calc(unsigned long long ts, struct ts_offset_corr *min, > + struct ts_offset_corr *max) > +{ > + long long tscor = min->offset + > + (((((long long)ts) - min->time)* > + (max->offset-min->offset))/(max->time-min->time)); There's potential of dividing by zero here. Can we handle (drop?) such invalid samples in tsync_offset_load() below? > + > + if (tscor < 0) > + return ts - llabs(tscor); > + > + return ts + tscor; > + > +} > + > +static unsigned long long timestamp_correct(unsigned long long ts, > + struct tracecmd_input *handle) > +{ > + static int min = -1; > + static int max = -1; Caching in static variables here is not thread safe and might bite users in the future when we transition this code to a library. How about dropping caching here and use binary search below instead? -- Slavi > + int i; > + > + if (handle->ts_offset) > + return ts + handle->ts_offset; > + if (!handle->ts_corr_count || !handle->ts_corr) > + return ts; > + > + /* We have only one offset, nothing to calc here */ > + if (handle->ts_corr_count == 1) > + return ts + handle->ts_corr[0].offset; > + > + /* We have two offsets, nothing to search here */ > + if (handle->ts_corr_count == 2) > + return timestamp_correction_calc(ts, &handle->ts_corr[0], > + &handle->ts_corr[1]); > + > + /* We have more than two offsets */ > + /* check if current ts fits in the last found time frame */ > + if (min >= 0 && max >= 0 && > + ts >= handle->ts_corr[min].time && > + ts <= handle->ts_corr[max].time) { > + return timestamp_correction_calc(ts, &handle->ts_corr[min], > + &handle->ts_corr[max]); > + } > + min = -1; > + max = -1; > + for (i = 0; i < handle->ts_corr_count; i++) { > + if (ts > handle->ts_corr[i].time) > + min = i; > + else if (ts <= handle->ts_corr[i].time) { > + max = i; > + break; > + } > + } > + if (min >= 0 && max >= 0 && min != max && > + min < handle->ts_corr_count && max < handle->ts_corr_count) > + return timestamp_correction_calc(ts, &handle->ts_corr[min], > + &handle->ts_corr[max]); > + > + return ts; > +} > + > /* > * Page is mapped, now read in the page header info. > */ > @@ -1049,7 +1118,7 @@ static int update_page_info(struct tracecmd_input *handle, int cpu) > kbuffer_subbuffer_size(kbuf)); > return -1; > } > - handle->cpu_data[cpu].timestamp = kbuffer_timestamp(kbuf) + handle->ts_offset; > + handle->cpu_data[cpu].timestamp = timestamp_correct(kbuffer_timestamp(kbuf), handle); > > if (handle->ts2secs) > handle->cpu_data[cpu].timestamp *= handle->ts2secs; > @@ -1776,7 +1845,7 @@ read_again: > goto read_again; > } > > - handle->cpu_data[cpu].timestamp = ts + handle->ts_offset; > + handle->cpu_data[cpu].timestamp = timestamp_correct(ts, handle); > > if (handle->ts2secs) { > handle->cpu_data[cpu].timestamp *= handle->ts2secs; > @@ -2101,6 +2170,34 @@ void tracecmd_set_ts2secs(struct tracecmd_input *handle, > handle->use_trace_clock = false; > } > > +static int tsync_offset_cmp(const void *a, const void *b) > +{ > + struct ts_offset_corr *ts_a = (struct ts_offset_corr *)a; > + struct ts_offset_corr *ts_b = (struct ts_offset_corr *)b; > + > + if (ts_a->time > ts_b->time) > + return 1; > + if (ts_a->time < ts_b->time) > + return -1; > + return 0; > +} > + > +static void tsync_offset_load(struct tracecmd_input *handle, char *buf) > +{ > + int i; > + long long *buf8 = (long long *)buf; > + > + for (i = 0; i < handle->ts_corr_count; i++) { > + handle->ts_corr[i].time = tep_read_number(handle->pevent, > + buf8+i, 8); > + handle->ts_corr[i].offset = tep_read_number(handle->pevent, > + buf8+handle->ts_corr_count+i, 8); > + } > + qsort(handle->ts_corr, > + handle->ts_corr_count, sizeof(struct ts_offset_corr), > + tsync_offset_cmp); > +} > + > static int handle_options(struct tracecmd_input *handle) > { > long long offset; > @@ -2111,6 +2208,7 @@ static int handle_options(struct tracecmd_input *handle) > struct input_buffer_instance *buffer; > struct hook_list *hook; > char *buf; > + int tsync; > int cpus; > > for (;;) { > @@ -2155,6 +2253,23 @@ static int handle_options(struct tracecmd_input *handle) > offset = strtoll(buf, NULL, 0); > handle->ts_offset += offset; > break; > + case TRACECMD_OPTION_TIME_SHIFT: > + /* > + * int (4 bytes) count of timestamp offsets. > + * long long array of size [count] of times, > + * when the offsets were calculated. > + * long long array of size [count] of timestamp offsets. > + */ > + handle->ts_corr_count = tep_read_number(handle->pevent, > + buf, 4); > + tsync = (sizeof(long long)*handle->ts_corr_count); > + if (size != (4+(2*tsync))) > + break; > + handle->ts_corr = malloc(2*tsync); > + if (!handle->ts_corr) > + return -ENOMEM; > + tsync_offset_load(handle, buf+4); > + break; > case TRACECMD_OPTION_CPUSTAT: > buf[size-1] = '\n'; > cpustats = realloc(cpustats, cpustats_size + size + 1); > -- > 2.20.1 >
On Fri, Mar 15, 2019 at 10:38 AM Tzvetomir Stoyanov <tstoyanov@vmware.com> wrote: > > The TRACECMD_OPTION_TIME_SHIFT is used when synchronizing trace time stamps between > two trace.dat files. It contains multiple long long (time, offset) pairs, describing > time stamps _offset_, measured in the given local _time_. The content of the option > buffer is: > first 4 bytes - integer, count of timestamp offsets > long long array of size _count_, local time in which the offset is measured > long long array of size _count_, offset of the time stamps > > Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com> > --- > include/trace-cmd/trace-cmd.h | 1 + > lib/trace-cmd/trace-input.c | 119 +++++++++++++++++++++++++++++++++- > 2 files changed, 118 insertions(+), 2 deletions(-) > > diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h > index f7c043a..5552396 100644 > --- a/include/trace-cmd/trace-cmd.h > +++ b/include/trace-cmd/trace-cmd.h > @@ -82,6 +82,7 @@ enum { > TRACECMD_OPTION_HOOK, > TRACECMD_OPTION_OFFSET, > TRACECMD_OPTION_CPUCOUNT, > + TRACECMD_OPTION_TIME_SHIFT, > }; > > enum { > diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c > index 0a6e820..714f01c 100644 > --- a/lib/trace-cmd/trace-input.c > +++ b/lib/trace-cmd/trace-input.c > @@ -75,6 +75,11 @@ struct input_buffer_instance { > size_t offset; > }; > > +struct ts_offset_corr { > + long long time; > + long long offset; > +}; > + > struct tracecmd_input { > struct tep_handle *pevent; > struct tep_plugin_list *plugin_list; > @@ -92,6 +97,8 @@ struct tracecmd_input { > bool use_pipe; > struct cpu_data *cpu_data; > long long ts_offset; > + int ts_corr_count; > + struct ts_offset_corr *ts_corr; > double ts2secs; > char * cpustats; > char * uname; > @@ -1028,6 +1035,68 @@ static void free_next(struct tracecmd_input *handle, int cpu) > free_record(record); > } > > +static inline unsigned long long > +timestamp_correction_calc(unsigned long long ts, struct ts_offset_corr *min, > + struct ts_offset_corr *max) > +{ > + long long tscor = min->offset + > + (((((long long)ts) - min->time)* > + (max->offset-min->offset))/(max->time-min->time)); > + > + if (tscor < 0) > + return ts - llabs(tscor); > + > + return ts + tscor; > + > +} > + > +static unsigned long long timestamp_correct(unsigned long long ts, > + struct tracecmd_input *handle) > +{ > + static int min = -1; > + static int max = -1; > + int i; > + > + if (handle->ts_offset) > + return ts + handle->ts_offset; > + if (!handle->ts_corr_count || !handle->ts_corr) > + return ts; > + > + /* We have only one offset, nothing to calc here */ > + if (handle->ts_corr_count == 1) > + return ts + handle->ts_corr[0].offset; > + > + /* We have two offsets, nothing to search here */ > + if (handle->ts_corr_count == 2) > + return timestamp_correction_calc(ts, &handle->ts_corr[0], > + &handle->ts_corr[1]); > + > + /* We have more than two offsets */ > + /* check if current ts fits in the last found time frame */ > + if (min >= 0 && max >= 0 && > + ts >= handle->ts_corr[min].time && > + ts <= handle->ts_corr[max].time) { > + return timestamp_correction_calc(ts, &handle->ts_corr[min], > + &handle->ts_corr[max]); > + } > + min = -1; > + max = -1; > + for (i = 0; i < handle->ts_corr_count; i++) { > + if (ts > handle->ts_corr[i].time) > + min = i; > + else if (ts <= handle->ts_corr[i].time) { > + max = i; > + break; > + } > + } > + if (min >= 0 && max >= 0 && min != max && > + min < handle->ts_corr_count && max < handle->ts_corr_count) > + return timestamp_correction_calc(ts, &handle->ts_corr[min], > + &handle->ts_corr[max]); > + > + return ts; > +} > + > /* > * Page is mapped, now read in the page header info. > */ > @@ -1049,7 +1118,7 @@ static int update_page_info(struct tracecmd_input *handle, int cpu) > kbuffer_subbuffer_size(kbuf)); > return -1; > } > - handle->cpu_data[cpu].timestamp = kbuffer_timestamp(kbuf) + handle->ts_offset; > + handle->cpu_data[cpu].timestamp = timestamp_correct(kbuffer_timestamp(kbuf), handle); > > if (handle->ts2secs) > handle->cpu_data[cpu].timestamp *= handle->ts2secs; > @@ -1776,7 +1845,7 @@ read_again: > goto read_again; > } > > - handle->cpu_data[cpu].timestamp = ts + handle->ts_offset; > + handle->cpu_data[cpu].timestamp = timestamp_correct(ts, handle); > > if (handle->ts2secs) { > handle->cpu_data[cpu].timestamp *= handle->ts2secs; > @@ -2101,6 +2170,34 @@ void tracecmd_set_ts2secs(struct tracecmd_input *handle, > handle->use_trace_clock = false; > } > > +static int tsync_offset_cmp(const void *a, const void *b) > +{ > + struct ts_offset_corr *ts_a = (struct ts_offset_corr *)a; > + struct ts_offset_corr *ts_b = (struct ts_offset_corr *)b; > + > + if (ts_a->time > ts_b->time) > + return 1; > + if (ts_a->time < ts_b->time) > + return -1; > + return 0; > +} > + > +static void tsync_offset_load(struct tracecmd_input *handle, char *buf) > +{ > + int i; > + long long *buf8 = (long long *)buf; > + > + for (i = 0; i < handle->ts_corr_count; i++) { > + handle->ts_corr[i].time = tep_read_number(handle->pevent, > + buf8+i, 8); > + handle->ts_corr[i].offset = tep_read_number(handle->pevent, > + buf8+handle->ts_corr_count+i, 8); > + } > + qsort(handle->ts_corr, > + handle->ts_corr_count, sizeof(struct ts_offset_corr), > + tsync_offset_cmp); > +} > + > static int handle_options(struct tracecmd_input *handle) > { > long long offset; > @@ -2111,6 +2208,7 @@ static int handle_options(struct tracecmd_input *handle) > struct input_buffer_instance *buffer; > struct hook_list *hook; > char *buf; > + int tsync; > int cpus; > > for (;;) { > @@ -2155,6 +2253,23 @@ static int handle_options(struct tracecmd_input *handle) > offset = strtoll(buf, NULL, 0); > handle->ts_offset += offset; > break; > + case TRACECMD_OPTION_TIME_SHIFT: We have to also check `handle->flags & TRACECMD_FL_IGNORE_DATE` and skip loading offset samples and correcting as in the two cases above. > + /* > + * int (4 bytes) count of timestamp offsets. > + * long long array of size [count] of times, > + * when the offsets were calculated. > + * long long array of size [count] of timestamp offsets. > + */ > + handle->ts_corr_count = tep_read_number(handle->pevent, > + buf, 4); > + tsync = (sizeof(long long)*handle->ts_corr_count); > + if (size != (4+(2*tsync))) > + break; > + handle->ts_corr = malloc(2*tsync); > + if (!handle->ts_corr) > + return -ENOMEM; > + tsync_offset_load(handle, buf+4); > + break; > case TRACECMD_OPTION_CPUSTAT: > buf[size-1] = '\n'; > cpustats = realloc(cpustats, cpustats_size + size + 1); > -- > 2.20.1 >
diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h index f7c043a..5552396 100644 --- a/include/trace-cmd/trace-cmd.h +++ b/include/trace-cmd/trace-cmd.h @@ -82,6 +82,7 @@ enum { TRACECMD_OPTION_HOOK, TRACECMD_OPTION_OFFSET, TRACECMD_OPTION_CPUCOUNT, + TRACECMD_OPTION_TIME_SHIFT, }; enum { diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c index 0a6e820..714f01c 100644 --- a/lib/trace-cmd/trace-input.c +++ b/lib/trace-cmd/trace-input.c @@ -75,6 +75,11 @@ struct input_buffer_instance { size_t offset; }; +struct ts_offset_corr { + long long time; + long long offset; +}; + struct tracecmd_input { struct tep_handle *pevent; struct tep_plugin_list *plugin_list; @@ -92,6 +97,8 @@ struct tracecmd_input { bool use_pipe; struct cpu_data *cpu_data; long long ts_offset; + int ts_corr_count; + struct ts_offset_corr *ts_corr; double ts2secs; char * cpustats; char * uname; @@ -1028,6 +1035,68 @@ static void free_next(struct tracecmd_input *handle, int cpu) free_record(record); } +static inline unsigned long long +timestamp_correction_calc(unsigned long long ts, struct ts_offset_corr *min, + struct ts_offset_corr *max) +{ + long long tscor = min->offset + + (((((long long)ts) - min->time)* + (max->offset-min->offset))/(max->time-min->time)); + + if (tscor < 0) + return ts - llabs(tscor); + + return ts + tscor; + +} + +static unsigned long long timestamp_correct(unsigned long long ts, + struct tracecmd_input *handle) +{ + static int min = -1; + static int max = -1; + int i; + + if (handle->ts_offset) + return ts + handle->ts_offset; + if (!handle->ts_corr_count || !handle->ts_corr) + return ts; + + /* We have only one offset, nothing to calc here */ + if (handle->ts_corr_count == 1) + return ts + handle->ts_corr[0].offset; + + /* We have two offsets, nothing to search here */ + if (handle->ts_corr_count == 2) + return timestamp_correction_calc(ts, &handle->ts_corr[0], + &handle->ts_corr[1]); + + /* We have more than two offsets */ + /* check if current ts fits in the last found time frame */ + if (min >= 0 && max >= 0 && + ts >= handle->ts_corr[min].time && + ts <= handle->ts_corr[max].time) { + return timestamp_correction_calc(ts, &handle->ts_corr[min], + &handle->ts_corr[max]); + } + min = -1; + max = -1; + for (i = 0; i < handle->ts_corr_count; i++) { + if (ts > handle->ts_corr[i].time) + min = i; + else if (ts <= handle->ts_corr[i].time) { + max = i; + break; + } + } + if (min >= 0 && max >= 0 && min != max && + min < handle->ts_corr_count && max < handle->ts_corr_count) + return timestamp_correction_calc(ts, &handle->ts_corr[min], + &handle->ts_corr[max]); + + return ts; +} + /* * Page is mapped, now read in the page header info. */ @@ -1049,7 +1118,7 @@ static int update_page_info(struct tracecmd_input *handle, int cpu) kbuffer_subbuffer_size(kbuf)); return -1; } - handle->cpu_data[cpu].timestamp = kbuffer_timestamp(kbuf) + handle->ts_offset; + handle->cpu_data[cpu].timestamp = timestamp_correct(kbuffer_timestamp(kbuf), handle); if (handle->ts2secs) handle->cpu_data[cpu].timestamp *= handle->ts2secs; @@ -1776,7 +1845,7 @@ read_again: goto read_again; } - handle->cpu_data[cpu].timestamp = ts + handle->ts_offset; + handle->cpu_data[cpu].timestamp = timestamp_correct(ts, handle); if (handle->ts2secs) { handle->cpu_data[cpu].timestamp *= handle->ts2secs; @@ -2101,6 +2170,34 @@ void tracecmd_set_ts2secs(struct tracecmd_input *handle, handle->use_trace_clock = false; } +static int tsync_offset_cmp(const void *a, const void *b) +{ + struct ts_offset_corr *ts_a = (struct ts_offset_corr *)a; + struct ts_offset_corr *ts_b = (struct ts_offset_corr *)b; + + if (ts_a->time > ts_b->time) + return 1; + if (ts_a->time < ts_b->time) + return -1; + return 0; +} + +static void tsync_offset_load(struct tracecmd_input *handle, char *buf) +{ + int i; + long long *buf8 = (long long *)buf; + + for (i = 0; i < handle->ts_corr_count; i++) { + handle->ts_corr[i].time = tep_read_number(handle->pevent, + buf8+i, 8); + handle->ts_corr[i].offset = tep_read_number(handle->pevent, + buf8+handle->ts_corr_count+i, 8); + } + qsort(handle->ts_corr, + handle->ts_corr_count, sizeof(struct ts_offset_corr), + tsync_offset_cmp); +} + static int handle_options(struct tracecmd_input *handle) { long long offset; @@ -2111,6 +2208,7 @@ static int handle_options(struct tracecmd_input *handle) struct input_buffer_instance *buffer; struct hook_list *hook; char *buf; + int tsync; int cpus; for (;;) { @@ -2155,6 +2253,23 @@ static int handle_options(struct tracecmd_input *handle) offset = strtoll(buf, NULL, 0); handle->ts_offset += offset; break; + case TRACECMD_OPTION_TIME_SHIFT: + /* + * int (4 bytes) count of timestamp offsets. + * long long array of size [count] of times, + * when the offsets were calculated. + * long long array of size [count] of timestamp offsets. + */ + handle->ts_corr_count = tep_read_number(handle->pevent, + buf, 4); + tsync = (sizeof(long long)*handle->ts_corr_count); + if (size != (4+(2*tsync))) + break; + handle->ts_corr = malloc(2*tsync); + if (!handle->ts_corr) + return -ENOMEM; + tsync_offset_load(handle, buf+4); + break; case TRACECMD_OPTION_CPUSTAT: buf[size-1] = '\n'; cpustats = realloc(cpustats, cpustats_size + size + 1);
The TRACECMD_OPTION_TIME_SHIFT is used when synchronizing trace time stamps between two trace.dat files. It contains multiple long long (time, offset) pairs, describing time stamps _offset_, measured in the given local _time_. The content of the option buffer is: first 4 bytes - integer, count of timestamp offsets long long array of size _count_, local time in which the offset is measured long long array of size _count_, offset of the time stamps Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com> --- include/trace-cmd/trace-cmd.h | 1 + lib/trace-cmd/trace-input.c | 119 +++++++++++++++++++++++++++++++++- 2 files changed, 118 insertions(+), 2 deletions(-)